JP4661576B2 - How to adjust the position of the projected image - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make it possible to surely and promptly adjust the positions of projected images projected on a screen by a plurality of projectors. <P>SOLUTION: The position adjustment method comprises an adjustment image data output apparatus 12 capable of outputting two adjustment image data, corresponding to two adjustment images with patterns whereby a prescribed characteristic appears on an overlapped region, when two projectors PJ1, PJ2 among a plurality of the projectors project the two adjustment images in a proper positional relation; an evaluation value calculation apparatus 13 that calculates evaluation value, cross-referenced with the characteristics on the basis of photographed image data, obtained by photographing the two adjustment images, at a prescribed position between the two projectors and a viewer side display screen of a rear projection screen SCR', when the two projectors project the two adjustment images; and a position adjustment control apparatus 14 for adjusting the positions of the two projected images, on the basis of the evaluation value. <P>COPYRIGHT: (C)2007,JPO&amp;INPIT

Description

  The present invention relates to a projection image position adjustment method, a projection image position adjustment device, a projection image position adjustment program, and a multi-projection image, which are used for a multi-projection display that projects a projection image from a plurality of projectors onto a screen. It relates to a projection display.

  There is known a multi-projection display that projects tiling projection or stacking projection of projected images from a plurality of projectors on a screen. In such a multi-projection display, the accuracy of the position adjustment of each projection image on the screen greatly affects the quality of the projection image.

  For example, when tiling projection is taken as an example, if the accuracy of position adjustment is low, the quality of the projected image will be greatly improved, such as discontinuous seams between the projected images and the overlapping area appearing blurred. There is a problem of deterioration.

In order to cope with this, in a multi-projection display, it is essential to adjust the position between each projected image. However, if this position adjustment is performed manually by the user, it takes a lot of time and effort. There is a problem that skill required for work is required.
For this reason, various techniques for automating position adjustment have been conventionally proposed (see, for example, Patent Document 1 and Patent Document 2).

  The technique disclosed in Patent Document 1 captures a plurality of test pattern images (having a luminance distribution of chevron waveforms) projected on a screen with a camera, and generates a plurality of test patterns from the captured image data. Each representative position (center position of the chevron waveform) is obtained, and based on the obtained representative positions, the interval between the test pattern images and the intersection of the line segment connecting each test pattern image and the adjacent screen are perpendicular to the horizontal direction. The distance in both or one of the directions is obtained, and using these distances, what kind of misalignment is measured is measured.

  In addition, the technique disclosed in Patent Document 2 displays and superimposes two adjustment patterns having a black display portion along a boundary portion between adjacent projection images and a white display portion on the inside by two projectors. Display a dark line on the part. And the width | variety of a black display part is reduced gradually, it images with a camera, the width change of a dark line is observed from the captured image data, and the disappearance position of a dark line is memorize | stored as a boundary position. Then, the position adjustment is performed so that the outline of the projected image projected from each projection apparatus is aligned with the boundary position.

JP 2001-356005 A JP 2002-365718 A

The technique disclosed in Patent Document 1 is considered to be able to detect a positional shift using an imaging device having a resolution lower than the resolution of the projected image. However, a complicated image analysis process is required to obtain the positional deviation. For this reason, there is a problem that an image data processing apparatus having a high processing capability is required, and the amount of calculation is large, so that high-speed positional deviation adjustment cannot be performed.
In addition, the technique disclosed in Patent Document 2 has a problem that the boundary position cannot be obtained with high accuracy unless a high-resolution imaging device having a resolution in pixel units of a projected image is used.

  The present invention makes it possible to adjust the position of projected images from a plurality of projectors projected on a screen at high speed and with high accuracy, and in particular, for projected images that are effective in a rear projection type multi-projection display or the like. An object of the present invention is to provide a position adjusting method, a projected image position adjusting device, a projected image position adjusting program, and a multi-projection display.

(1) In the projection image position adjustment method of the present invention, the position of two projection images projected on a screen so as to have an overlapping region from two projectors in a multi-projection display having a plurality of projectors is adjusted. A method for adjusting the position of a projected image to be adjusted using
Two pieces of adjustment image data corresponding to the two adjustment images having a pattern in which a predetermined feature appears in the superposition region when the two adjustment images are projected in an appropriate positional relationship. A first step for two projectors;
Imaging obtained by photographing the two adjustment images at a predetermined position between the two projectors and the viewer-side display surface when the two adjustment images are projected from the two projectors A second step of calculating an evaluation value associated with the feature based on image data;
A third step of adjusting the position of the two projected images based on the evaluation value;
Have
The feature is a pixel value in the captured image data,
The evaluation value is calculated based on the number of pixels having the pixel value equal to or greater than a threshold value and the difference between the pixel value of each pixel having the maximum pixel value and the pixel having the minimum pixel value. And calculated using
The third step is characterized in that the position of the two projection images is adjusted with the position where the evaluation value is maximized as the optimum projection position of the two projection images .

As described above, according to the method for adjusting the position of a projected image of the present invention, an adjustment image in which a predetermined feature appears in the superimposed region when projected with an appropriate positional relationship is projected onto the screen by two projectors. The evaluation value associated with the feature is calculated based on the captured image data at a predetermined position , the number of pixels equal to or greater than the threshold, the pixel having the maximum pixel value of each pixel, and the minimum By calculating the evaluation value using two parameters of contrast calculated based on the difference between the pixel values of the pixels having the pixel value, the two evaluation images are appropriately positioned. It is possible to appropriately evaluate whether or not the adjustment has been made.

  Specifically, when performing position adjustment using two adjustment images, a final projection image of the two adjustment images (for example, an image displayed on the viewer-side display surface of the screen) is captured. Rather than using the obtained captured image data, position adjustment is performed based on captured image data obtained by capturing an image of an arbitrary cross section on the optical path of the projected image from the projector. Therefore, in the present invention, for example, an imaging means such as a camera is installed on the opposite side (rear side) of the rear projection screen to the viewer side display surface, and is projected on the rear projection surface of the rear projection screen. The present invention can be applied to a rear projection type multi-projection display that performs position adjustment based on captured image data obtained by capturing a projected image.

(2) In the projected image position adjustment method according to (1), the second step moves at least one of the two adjustment images in the horizontal direction or the vertical direction in units of pixels. It is preferable to calculate the evaluation value every time the adjustment image is moved in units of pixels.
Accordingly, an evaluation value for each movement of the adjustment image in units of one pixel can be calculated, and position adjustment can be performed with accuracy in units of one pixel.

(3) In the projected image position adjustment method according to (1) or (2), it is preferable that the pattern has a line drawing having a width corresponding to one pixel.
In this way, by making the patterns of the two adjustment images into line drawings having a width of one pixel, it is possible to observe the features that appear due to the overlapping of the patterns for each movement of the adjustment image in units of one pixel. As a result, the evaluation value for each pixel can be appropriately calculated, and the position can be adjusted with accuracy for each pixel.

(4) In the projected image position adjustment method according to any one of (1) to (3), the feature is preferably a pixel value in the captured image data.
Thus, by representing the feature with a pixel value, the feature can be represented as an objective value. In the present invention, it is assumed that the pixel value represents a luminance value. Accordingly, when the two adjustment images are appropriately adjusted, a region with high luminance appears in the overlapping region.

  (5) In the projected image position adjustment method according to (4), the evaluation value is calculated based on a difference between the number of pixels having the pixel value equal to or greater than a threshold and the pixel value of each pixel. It is preferable that the third step adjusts the position of the two projection images with the position where the evaluation value is maximized as the optimum projection position of the two projection images.

Thus, the evaluation value is calculated using the number of pixels equal to or greater than the threshold value and the contrast, and the position where the calculated evaluation value is the maximum is set as the optimum projection position of the two projection images. Note that the number of pixels equal to or greater than the threshold is the number of pixels having a luminance equal to or higher than a predetermined luminance value, that is, when each pattern of two adjustment images is superimposed, a high-luminance pixel in the overlapping region. Therefore, the number of high luminance pixels (the number of high luminance pixels) can be used as an index for determining the degree of position adjustment. Similarly, since the contrast becomes higher when the positions of the two adjustment images are appropriately adjusted, the contrast can also be used as an index for determining the degree of position adjustment.
Therefore, by calculating the evaluation value using the two parameters of the number of pixels equal to or greater than the threshold and the contrast, the calculated evaluation value appropriately determines whether or not the two adjustment images are appropriately adjusted. It is a value that can be evaluated.

  (6) In the projection image position adjustment method according to (5), the threshold value is set to a value corresponding to a color that appears only when the patterns in the two adjustment images overlap. It is preferable.

  For example, when the present invention is applied to a rear projection type multi-projection display, the characteristics of the screen for rear projection used in the rear projection type multi-projection display are taken into consideration.

  One of the characteristics of the rear projection screen is that the rear projection screen reflects light projected from the opposite side (rear side) of the front display surface of the screen to the rear projection surface as much as possible. And has a characteristic that more light is output from the front display surface of the screen. Because the rear projection screen has these characteristics, the amount of light that can be observed from the projection surface on the rear side of the screen is greatly reduced compared to the amount of light that can be observed from the front display surface of the screen in the front projection type. Will be.

  As a result, when the imaging device is installed on the rear side of the rear projection screen and the rear projection surface of the rear projection screen is imaged by the imaging device, the captured image data is obtained from the front projection type multi-projection display. The luminance is greatly reduced as compared with captured image data captured by an imaging device that captures the front side of the screen.

  In order to deal with such characteristics of the rear projection screen, the image data obtained by imaging the rear projection surface of the rear projection screen by setting a low threshold value for determining that the pixel is a high luminance pixel. Even when the luminance of the pixel decreases, the number of pixels having a certain pixel value (luminance value) can be obtained.

  (7) In the projected image position adjustment method according to (5) or (6), the difference in pixel value between the pixels when calculating the contrast is the minimum pixel value and the minimum pixel value. It is preferable that the difference is between pixel values of pixels having pixel values.

(8) In the projection image position adjustment method according to (7), it is preferable that a value obtained by a product of each color component constituting the captured image data is used as the pixel value of each pixel.
Thus, by multiplying each color component, the difference in pixel value of each pixel can be clearly expressed. Thereby, the pixel having the maximum pixel value and the pixel having the minimum pixel value can be accurately and easily specified, and the contrast can be obtained appropriately.

(9) In the projected image position adjustment method according to any one of (5) to (8), the evaluation value is obtained based on a sum of the number of pixels equal to or greater than the threshold and the contrast. It is preferable.
Thereby, it is possible to obtain an evaluation value in consideration of the number of pixels equal to or greater than the threshold and the contrast. Further, since the evaluation value is calculated using two parameters of the number of pixels equal to or greater than the threshold and the contrast, as described above, the calculated evaluation value is appropriately adjusted by the two adjustment images. It becomes a value that can be appropriately evaluated whether or not it is.

(10) In the projected image position adjustment method according to (9), it is preferable to normalize the number of pixels equal to or greater than the threshold value and the contrast.
This is because there is a large difference between the number of pixels equal to or greater than the threshold (the number of high-luminance pixels) and the contrast value. By normalizing the number of pixels equal to or greater than the threshold and the contrast, An evaluation value reflecting both of them in an equal manner can be obtained without being biased toward either the number of pixels equal to or greater than the threshold value or the two feature quantities of contrast.

(11) In the projected image position adjustment method according to (10), it is preferable to perform weighting so that the contrast is more reflected in the evaluation value.
This is because the contrast is not easily affected by various interference factors such as the exposure setting of the imaging device and the lighting conditions of the space where the multi-projection display is installed, and a stable measurement result can be obtained even when the environmental conditions change to some extent. In view of the feature of being able to perform the evaluation, it is possible to obtain a more appropriate evaluation value by performing weighting with more importance on the contrast.

  (12) In the projected image position adjustment method according to any one of (1) to (11), one of the two adjustment images includes a first pattern of a first color. And the other adjustment image has a second pattern of the second color, and the first color and the second color are overlapped with the first pattern and the second pattern. It is preferable that values of a red component, a green component, and a blue component in each of the two adjustment images are set so that the predetermined feature appears.

  In this way, the values of the R (red), G (green), and B (blue) color components are set so that the predetermined features appear in the overlapping regions of the two adjustment images. Thus, when the two adjustment images are appropriately superimposed, it is possible to cause a feature that the two adjustment images originally do not have to appear.

  (13) In the projected image position adjustment method according to any one of (1) to (12), in the second step, the two adjustment images are performed a plurality of times with the same positional relationship. It is preferable that the evaluation value is calculated by photographing.

  As described above, by calculating the evaluation value using the captured image data obtained by a plurality of times of imaging, it is possible to obtain a highly accurate evaluation value in which the influence of noise of the imaging device is reduced. For example, it is conceivable that an average value of evaluation values calculated using captured image data obtained by a plurality of times of imaging is obtained, and the average value is set as an evaluation value to be obtained.

(14) In the method for adjusting a position of a projected image according to any one of (1) to (13), the third step includes an image forming region in an electro-optic modulation device of one of two projectors. It is preferable to adjust the position of the two projected images by moving the position of the effective image display area in units of pixels.
In this way, the projected image can be moved in units of pixels by using the function that the projector originally has.

  (15) In the projected image position adjustment method according to any one of (1) to (14), the multi-projection display is a rear projection multi-projection display, and the captured image data is the rear projection-type multi-projection display. It is preferable that the image data is obtained by capturing the adjustment image projected on a projection surface opposite to the viewer-side display surface in a rear projection screen used in a projection multi-projection display.

  As described above, since the multi-projection display is a rear projection type multi-projection display, the method for adjusting the position of a projected image according to the present invention can exhibit a greater effect. That is, the present invention makes it possible to adjust the position of a projected image in consideration of the characteristics of a rear projection screen used in a rear projection type multi-projection display.

  Specifically, as described above, when the imaging device is installed on the rear side of the rear projection screen and the rear projection surface of the rear projection screen is imaged from the imaging device, the captured image data has luminance. In addition to the characteristics such as a significant reduction, the characteristics of the rear projection screen, which is another characteristic of the rear projection screen (details will be described later), such as the focus of the image on the front side display surface and the rear side projection surface are significantly different. The position of the projected image is adjusted. Thereby, in the rear projection type multi-projection display, it is possible to adjust the position with high accuracy in units of one pixel.

  (16) According to the projection image position adjusting apparatus of the present invention, the position of two projection images projected on the screen so as to have an overlapping region from two projectors in a multi-projection display having a plurality of projectors is adjusted to two adjustment images. A projection image position adjusting device that adjusts using the two, wherein the two adjustment images have patterns in which a predetermined feature appears in the superimposed region when the two adjustment images are projected in an appropriate positional relationship. An adjustment image data output device capable of outputting two adjustment image data corresponding to the adjustment image to the two projectors, and the two projectors when the two adjustment images are projected from the two projectors The two adjustment images at a predetermined position from the screen to the viewer side display surface of the screen An evaluation value calculation device that calculates an evaluation value associated with the feature based on captured image data obtained in this manner, and a position adjustment control device that adjusts the position of the two projected images based on the evaluation value. It is characterized by.

  This projected image position adjusting apparatus can also achieve the same effect as the projected image position adjusting method described in (1). The projected image position adjusting device preferably has the same characteristics as the projected image position adjusting methods (2) to (15).

  (17) The projection image position adjustment program of the present invention is configured to adjust the positions of two projection images projected on a screen so as to have an overlapping area from two projectors in a multi-projection display having a plurality of projectors. A projected image position adjusting program for adjusting using the image, wherein the projected image has a pattern in which a predetermined feature appears in the superimposed region when the two adjustment images are projected in an appropriate positional relationship. A first step of providing two adjustment image data corresponding to two adjustment images to the two projectors; and the two projectors when the two adjustment images are projected from the two projectors. The two adjustment images are taken at a predetermined position while reaching the viewer's display surface. A second step of calculating an evaluation value associated with the feature based on the captured image data obtained as a result, and a third step of adjusting the position of the two projected images based on the evaluation value. Features.

  Also in this projected image position adjustment program, the same effect as the projected image position adjustment method described in (1) can be obtained. The projected image position adjustment program preferably has the same characteristics as the projected image position adjustment methods (2) to (15).

  (18) A multi-projection display of the present invention is a multi-projection display having a plurality of projectors, and capable of projecting onto a screen such that projected images from the plurality of projectors have an overlapping region, Two adjustment image data corresponding to the two adjustment images having a pattern in which a predetermined feature appears in the superimposed region when the image is projected in an appropriate positional relationship can be output to the two projectors. Image data output device for adjustment, and the two adjustments at a predetermined position between the two projectors and the viewer side display surface when the two adjustment images are projected from the two projectors Associated with the feature based on the captured image data obtained by capturing the image. An evaluation value calculating device for calculating an evaluation value, characterized by further comprising a position adjustment control apparatus for adjusting the position of the two projection images on the basis of the evaluation value.

  Since the multi-projection display having a plurality of projectors has a configuration for performing such position adjustment, the position adjustment of the projected image projected from each projector can be performed at high speed and high accuracy with a small amount of calculation. Note that this multi-projection display also preferably has the same characteristics as the projection image position adjustment methods (2) to (15).

  (19) The multi-projection display according to (18) is preferably configured to be capable of tiling projection on a screen so that a plurality of projection images from the plurality of projectors have an overlapping region.

  As described above, even in a multi-projection display in which tiling projection is performed with adjacent areas between adjacent projection images among projection images projected from a plurality of projectors, the position adjustment of the projection images from each projector is small. The calculation amount can be performed at high speed and with high accuracy.

  (20) The multi-projection display according to (18) is preferably configured to be capable of stacking projection on a screen so that a plurality of projection images from the plurality of projectors have an overlapping region.

  As described above, even in a multi-projection display such as stacking projection in which projected images projected from a plurality of projectors are projected in the same projection area, the position adjustment of the projected images from each projector can be performed quickly with a small amount of calculation. And it can be performed with high accuracy.

  The method for adjusting the position of the projected image according to the embodiment of the present invention will be described below. The projection image position adjusting method according to the embodiment of the present invention is particularly effective when applied to a rear projection type multi-projection display.

  Before describing the method for adjusting the position of the projected image according to the embodiment of the present invention, the method for adjusting the position of the projected image applied to the front projection type multi-projection display will be described, and then the rear projection type multi-projection display. An example in which the method for adjusting the position of a projected image according to an embodiment of the present invention is applied will be described. The projected image position adjustment method applied to the front projection type multi-projection display is referred to as a “basic projected image position adjustment method”.

  FIG. 1 is a diagram showing a configuration of a front projection type multi-projection display. The multi-projection display shown in FIG. 1 has two left and right projectors PJ1 and PJ2 arranged in a horizontal direction for easy understanding, and each projector PJ1 and PJ2 is included in a part of each projected image. It is assumed that tiling projection is possible on the screen SCR as a projection surface so as to have an overlapping region. FIG. 1 is a view of the screen SCR and the projectors PJ1 and PJ2 as viewed from above.

  The multi-projection display shown in FIG. 1 includes two projectors PJ1 and PJ2, and a projected image position adjusting device 1 having a function of adjusting the position of the projected images from the two projectors PJ1 and PJ2. .

  It is assumed that projectors PJ1 and PJ2 can move the display position of the projected image on the screen SCR in the horizontal and vertical directions in units of one pixel by an external operation. If the image display position cannot be moved by an external operation, for example, in an image data output device (such as a personal computer), the image to be displayed itself is moved in the horizontal and vertical directions in units of one pixel. It is assumed that this can be dealt with by providing the projectors PJ1 and PJ2 with the projectors.

  The projected image position adjusting device 1 includes an image pickup device 11 that can pick up the adjustment images CG1 and CG2 that are tiled and projected on the screen SCR with a partial overlapping area, and two adjustment images CG1 and CG1. Based on the adjustment image data output device 12 capable of outputting the adjustment image data CGD1 and CGD2 corresponding to CG2 to the projectors PJ1 and PJ2, and the imaged image data from the imaging device 11, an evaluation value for the adjustment image is calculated. Based on the evaluation value calculation device 13 and the evaluation result by the evaluation value calculation device 13, the optimal projection position of the projection image from the projectors PJ1 and PJ2 is acquired, and the position adjustment of the projection image is performed based on the acquired position. And a position adjustment control device 14 for performing the operation.

  Note that one of the two adjustment images CG1 and CG2 (the adjustment image CG1 projected by the projector PJ1) is fixed, and the other adjustment image (the adjustment image CG2 projected by the projector PJ2) ) Is moved in the vertical direction (up and down direction) on the screen SCR, and the optimum projection position is detected.

  FIG. 2 is a diagram showing in detail the configuration of the position adjustment device 1 for the projected image. The adjustment image data output device 12 includes an adjustment image data generation unit 121 that generates adjustment image data CGD1 and CGD2 for the projectors PJ1 and PJ2, and the generated adjustment image data CGD1 and CGD2 corresponding to the projectors. And an adjustment image data output unit 122 for outputting to PJ1 and PJ2.

  The imaging device 11 images adjustment images CG1 and CG2 corresponding to the adjustment image data CGD1 and CGD2 from the projectors PJ1 and PJ2 projected on the screen SCR, and outputs the captured image data. In addition, this imaging device 11 can use the thing of the resolution lower than the resolution of the projection image projected on the screen SCR.

  The evaluation value calculation device 13 stores a captured image data input unit 131 that inputs captured image data obtained by the imaging device 11 capturing the adjustment images CG1 and CG2 on the screen SCR, and stores the input captured image data. The captured image data storage unit 132, an evaluation value calculation unit 133 that calculates an evaluation value (details will be described later) based on the positional relationship between the adjustment images CG1 and CG2, and the position obtained by the movement of the adjustment image CG2 and the calculated evaluation value And a position / evaluation value storage unit 134 that stores them in correspondence with each other.

  The position adjustment control device 14 includes a projection image position control unit 141 that can move and control the projection image positions of the projectors PJ1 and PJ2 in units of one pixel, and positions stored in the position / evaluation value storage unit 134 of the evaluation value calculation device 13. And the evaluation value for the position, the maximum evaluation value of the evaluation values and the position (referred to as the maximum evaluation position) are acquired, and the maximum evaluation position for the acquired maximum evaluation value is the maximum evaluation position storage unit 142. Based on the position / evaluation value acquisition unit 143 to be stored, the maximum evaluation value acquired by the position / evaluation value acquisition unit 143, and the maximum evaluation position at that time, movement control information is transmitted to the projection image position control unit 141. And a control unit 144 for providing

  FIG. 3 is a diagram schematically illustrating an example of the adjustment images CG1 and CG2 that are separately projected on the screen SCR from the two projectors PJ1 and PJ2 arranged in the horizontal direction. FIG. 3A shows the adjustment image CG1, and FIG. 3B shows the adjustment image CG2. Adjustment images CG1 and CG2 shown in FIG. 3 are adjustment images for adjusting the position of each projection image from the projectors PJ1 and PJ2 in the vertical direction on the screen SCR.

  As described above, the adjustment images CG1 and CG2 are generated as adjustment images corresponding to the two projectors PJ1 and PJ2, respectively, and the generated two adjustment images are transferred to the corresponding projectors PJ1 and PJ2. However, it is also possible to generate one adjustment image as the adjustment image and divide the adjustment image into the corresponding projectors PJ1 and PJ2. The same applies to the adjustment image used in the projection image position adjustment method according to each embodiment described later.

  The adjustment images CG1 and CG2 have a pattern such that when the adjustment images CG1 and CG2 are projected on the screen SCR with an appropriate positional relationship, a predetermined feature appears in the overlapping region.

  That is, in the two adjustment images CG1 and CG2, one adjustment image CG1 has a first pattern of the first color, and the other adjustment image CG2 has a second pattern of the second color. The first color and the second color are the red component in each of the two adjustment images so that the characteristic white appears when the first pattern and the second pattern are superimposed, Pixel values of the green component and blue component are set.

  For example, the first color in the adjustment image CG1 is a color having a relatively strong red component and a relatively weak green component, and the second color in the adjustment image CG2 is a relatively strong blue component. And a color having a relatively weak green component. Specifically, for the first color in the adjustment image CG1, the pixel values (gradation values) of the color components of R (red), G (green), and B (blue) are R = 255, G = 160, B = 0, and for the second color in the adjustment image CG2, the pixel values (gradation values) of the color components of R (red), G (green), and B (blue) are R = Set 0, G = 160, and B = 255. The background color is preferably black. In addition, it is assumed that the pixel value used in each embodiment of the present invention represents a luminance value.

  In order to make the pixel value in the overlapping region of the adjustment images CG1 and CG2 white (R = 255, G = 255, B = 255), ideally, G (green) of the adjustment images CG1 and CG2 Although the component should be 128, in reality, the luminance characteristics of the captured image data may change due to the effects of the gamma characteristics, illumination conditions, and the like of the projectors PJ1 and PJ2. For this reason, G (green) = 160 is set. Thus, the value of G (green) can be set to a value that is optimal for the conditions at that time.

  In the above example, the R and B pixel values are fixed to 255 or 0, respectively, and G is variably set to an optimum value. However, the G and B pixel values are fixed to 255 or 0, respectively. Then, R may be variably set to an optimum value, or R and G pixel values may be fixed to 255 or 0, respectively, and B may be variably set to an optimum value. . However, since it is general that the imaging device has high sensitivity to G (green), it is preferable to variably set G (green) to an optimum value.

  In addition, each pattern (first pattern and second pattern) of the adjustment images CG1 and CG2 is a pattern based on a line drawing including a plurality of horizontal lines. The width (thickness) of each line corresponds to one pixel of an electro-optic modulation device (referred to as a liquid crystal modulation device) in the projectors PJ1 and PJ2, as shown in the enlarged view of the dashed frame in FIG. The interval between the lines corresponds to 20 pixels of the liquid crystal modulation device in the projectors PJ1 and PJ2.

  Next, a basic method for adjusting the position of a projected image in the multi-projection display shown in FIG. 1 will be described. Here, the resolution of each liquid crystal modulation device in the projectors PJ1 and PJ2 is horizontal 1280 pixels × vertical 720 pixels, and the resolution of the imaging device is horizontal 1280 pixels × vertical 1024 pixels.

  First, the user adjusts the position of the two adjustment images CG1 and CG2 within a possible range by manual operation. Note that a position set by position adjustment by a user's manual operation is referred to as an initial position.

  The final fine adjustment from the initial position is performed by applying a basic method for adjusting the position of the projected image to determine the optimum projection position. The procedure for adjusting the position of the projected image will be described below.

  First, the adjustment image data output device 12 outputs the adjustment image data CGD1 to the projector PJ1 that projects the left projection image on the screen SCR, and the adjustment image data CGD1 is projected to the projector PJ2 that projects the right projection image. Image data CGD2 is output. Among the adjustment image data CGD1 and CGD2, the adjustment image data CGD1 has pixel values of R = 255, G = 160, and B = 0, and the adjustment image data CGD2 has R = 0, G = It has a pixel value of 160, B = 255.

  FIG. 4 is a diagram schematically showing a state in which the adjustment images CG1 and CG2 shown in FIG. 3 are projected on the screen SCR with a partly overlapping region. As shown in FIG. 4, on the screen SCR, an adjustment image CG1 having pixel values of R = 255, G = 160, B = 0 by the projector PJ1, and R = 0, G = 160, B by the projector PJ2. = Adjustment image CG2 having a pixel value of = 255 is projected with a partial overlap area. Note that the adjustment image CG1 and the adjustment image CG2 in FIG. 4 are in a state before the position adjustment is performed.

  After the adjustment images CG1 and CG2 are projected on the screen SCR, one of the adjustment images CG1 and CG2 is moved in the vertical direction in units of one pixel. As described above, in this case, the adjustment image CG1 is fixed, and the position of the adjustment image CG2 is moved in units of one pixel. The adjustment image CG2 can be easily moved in units of pixels by using a function that can move the position of the effective image display area in the image forming area in the liquid crystal modulation device of the projector PJ2 in units of pixels. .

  The adjustment image CG2 projected by the projector PJ2 from the initial position set by the position adjustment by manual operation is moved to a position (this is set as a processing start position) by 10 pixels in the vertical direction (upward). . Next, an operation of sequentially moving the adjustment image CG2 downward by 20 pixels in units of one pixel from the processing start position is performed.

  As described above, the position where the adjustment image CG2 projected by the projector PJ2 is moved 10 pixels in the vertical direction from the initial position set by the manual operation is set as the processing start position, and 20 pixels from the processing start position. The initial position set by manual operation has a certain degree of accuracy even if it is manual operation, and is optimally within a range of about 10 pixels in the vertical direction with reference to the initial position. This is because the probability that a projection position exists is high. By performing such an operation, the optimum projection position can be found more efficiently.

  FIG. 5 is an enlarged view of the superimposed areas of the adjustment images CG1 and CG2 in the captured image data from the imaging device 11 at each position of the adjustment image CG2. Each image shown in FIG. 5 shows the state of the adjustment images CG1 and CG2 at each position when an operation for sequentially moving the adjustment image CG2 downward by 20 pixels in units of one pixel from the processing start position is performed. Yes. In FIG. 5, the numerical values “1” to “20” attached to the lower left of each image are numbers indicating the respective positions when the adjustment image CG2 is moved by 20 pixels from the processing start position. “1” is a processing start position.

  On the other hand, the imaging device 11 captures the adjustment images CG1 and CG2 on the screen SCR in accordance with the movement of the adjustment image CG2 in units of one pixel, and outputs the captured image data. The captured image data is input to the captured image data input unit 131 and stored in the captured image data storage unit 132. Then, the evaluation value calculation unit 133 calculates an evaluation value for each position of one pixel unit of the adjustment image CG2 using the captured image data stored in the captured image data storage unit 132. The evaluation value is calculated as follows.

  As shown in FIG. 5, when the adjustment image CG2 is moved in units of one pixel and the adjustment images CG1 and CG2 have a predetermined positional relationship, the original adjustment image CG1 and CG1 are overlapped with the adjustment images CG1 and CG2. Features that do not exist in CG2 appear. Here, the feature that appears in the superimposed region of the adjustment images CG1 and CG2 is a change in the pixel value in the captured image data due to the superimposition of the lines of the adjustment images CG1 and CG2, and in this case, both are appropriately If superposed, white appears in the superposed region.

  Since FIG. 5 is a monochrome drawing, it is difficult to read the appearance of white from FIG. 5, but in practice it is easy to read the appearance of white on the original color image of FIG. In this case, in the overlapping region of the adjustment image CG1 and the adjustment image CG2, white having a pixel value that has reached a predetermined threshold value (the threshold value will be described later) is displayed in pink so that It becomes even easier to read the appearance of white on the color image.

  Although it cannot be easily read from FIG. 5, a white area starts to appear from the position “6”, and the white area becomes the maximum at the position “8”, and thereafter, “9”, “10”,. As the position advances, it can be read from FIG. 6 that will be described later that the white area rapidly decreases.

  In FIG. 5, it can be determined that the adjustment images CG1 and CG2 are in an appropriate positional relationship at the position “8”. The determination that the adjustment images CG1 and CG2 are in an appropriate positional relationship can be made based on the number of pixels that are white from the captured image data.

  At this time, whether or not the color is white can be determined based on whether or not the pixel value of each pixel is equal to or greater than a predetermined value. That is, it is ideal that the pixel value is R, G, B = (255, 255, 255). However, in the basic method for adjusting the position of the projected image, the pixel as the threshold value is used. For example, the value is set as R, G, B = (240, 240, 240), and the pixel value is determined as white when R, G, B = (240, 240, 240) or more.

  Here, the threshold value is not R, G, B = (255, 255, 255), but R, G, B = (240, 240, 240) is a device characteristic such as a gamma characteristic and illumination conditions. This is because a certain margin is provided in consideration of fluctuation due to the above.

  FIG. 6 is a diagram illustrating the number of pixels determined to be white at each position from the processing start position “1” to a position “20” moved by 20 pixels. As shown in FIG. 6, the number of pixels determined to be white at position “8” is the largest. The number of pixels for each position shown in FIG. 6 is calculated by the evaluation value calculation unit 133 in FIG. 2, and the calculated number of pixels is associated with each position in the position / value of the evaluation value calculation device 13 in FIG. It is stored in the evaluation value storage unit 134.

  Then, the position / evaluation value acquisition unit 143 of the position adjustment control device 14 in FIG. 2 maximizes the position having the maximum number of pixels from the contents stored in the position / evaluation value storage unit 134 of the evaluation value calculation device 13. Acquired as a position, and the acquired maximum evaluation position is stored in the maximum evaluation position storage unit 142. In this case, since the position “8” is the maximum evaluation position having the maximum number of pixels, the position “8” is stored in the maximum evaluation position storage unit 142 as the maximum evaluation position.

  That is, FIG. 6 shows that each line of the adjustment image CG1 and each line of the adjustment image CG2 are overlapped in an optimum projection position relationship in the vertical direction when the adjustment image CG2 is set to the position “8”. In this positional relationship, if the projectors PJ1 and PJ2 perform projection, each projection image is projected at the optimum projection position in the vertical direction.

  Therefore, the position adjustment is performed so that the maximum evaluation position is the projection position of the projection image of the projector PJ2. As a result, the projected images of the projectors PJ1 and PJ2 become optimum projection positions that have been appropriately adjusted in the vertical direction, and high-quality images that do not cause discontinuous seams or blurs in the overlapping region. Can be displayed.

  Further, the resolution of the imaging device 11 used in the multi-projection display shown in FIG. 1 is horizontal 1280 pixels × vertical 1024 pixels, and even a relatively low resolution of about 1 million pixels has a higher resolution than that. The position of the projected image (here, the resolution of one projector is horizontal 1280 × vertical 720) can be adjusted in units of one pixel.

  In the basic projection image position adjustment method described above, the position of the adjustment image CG2 is determined by fixing the adjustment image CG1 and moving the adjustment image CG2 among the adjustment images CG1 and CG2. However, it goes without saying that the adjustment image CG2 may be fixed and the adjustment image CG1 may be moved.

  The basic method for adjusting the position of the projected image has been described above. Next, an example in which this basic method for adjusting the position of a projected image is applied to a rear projection type multi-projection display will be described with reference to the following embodiments.

  By the way, it has been experimentally confirmed that if the above-described basic projection image position adjustment method is applied to a rear projection type multi-projection display as it is, highly accurate position adjustment may not be performed. This is considered to be due to the influence of the characteristics of a rear projection screen (referred to as a rear projection screen) used in a rear projection type multi-projection display.

  Here, the characteristics of the rear projection screen that are considered to affect the accuracy of the position adjustment will be described as “rear projection screen characteristic 1” and “rear projection screen characteristic 2”.

(Characteristics of rear projection screen 1)
In the rear projection type, an image projected from the projector, that is, light passes through the rear projection screen and reaches the viewer side display surface (referred to as the front side display surface). Therefore, in order to provide a brighter image on the front display surface, the rear projection screen, as described above, transmits light projected from the opposite side (rear side) of the screen to the rear side of the screen. It is necessary to have such characteristics that more light is output from the front display surface of the screen without being reflected as much as possible by the side projection surface (referred to as the rear projection surface).

  Because the rear projection screen has such characteristics, the amount of light that can be observed from the rear side projection surface of the screen is greatly reduced compared to the amount of light that can be observed from the front side display surface of the screen in the front projection type. It will be.

  As a result, the rear projection surface of the rear projection screen is imaged by an imaging device installed on the rear side of the rear projection screen as in the rear projection multi-projection display according to the embodiment of the present invention described below. The captured image data obtained in this way has a luminance significantly higher than that of the captured image data obtained by the imaging device that images the front display surface of the screen in the front projection type multi-projection display as shown in FIG. It will drop to. For this reason, if the position adjustment by the basic method for adjusting the position of the projected image described above is performed as it is, a case where the position adjustment with high accuracy cannot be performed may occur.

(Rear projection screen characteristics 2)
Generally, a rear projection screen has a special lens structure inside the screen in order to ensure a wider viewing angle on the front display surface. For this reason, the focus of the image on the front side display surface and the rear side projection surface is greatly different, and it is necessary to set the focus of each projector so that the focus is appropriate when viewed from the front side display surface. For this reason, the focus of the image projected on the rear projection surface of the screen is in a state where “blurring” has occurred. Therefore, the captured image data captured by the imaging device installed on the rear side of the screen is also image data in which “blurring” occurs in the focus, and it is difficult to adjust the position with high accuracy in units of one pixel.

  Therefore, in the present invention, in consideration of the characteristics 1 and 2 of the rear projection screen, in order to enable highly accurate position adjustment in the rear projection type multi-projection display, the basic projection image described above is used. Improve the position adjustment method. Hereinafter, embodiments of the present invention will be described.

[Embodiment 1]
FIG. 7 is a diagram showing a configuration of a multi-projection display to which the projection image position adjustment method according to the first embodiment of the present invention is applied. The multi-projection display shown in FIG. 7 is a rear projection type multi-projection display, and the screen SCR is a rear projection screen SCR ′ with respect to the front projection type multi-projection display shown in FIG. The difference is that the two projectors PJ1 and PJ2 and the imaging device 11 in the projection image position adjusting device 1 are installed on the rear side of the rear projection screen SCR ′.

  Therefore, in the multi-projection display to which the projection image position adjustment method according to the first embodiment is applied, the projection images from the two projectors PJ1 and PJ2 are projected onto the rear-side projection surface R of the rear projection screen SCR ′. Then, the imaging device 11 captures a projection image projected on the rear projection surface R of the rear projection screen SCR ′. Also, the viewer looks at the front side display surface F of the rear projection screen SCR '.

  The rear projection type multi-projection display shown in FIG. 7 has an adjustment image data output device 12, an evaluation value calculation device 13, and a position adjustment control, similar to the projection image position adjustment device 1 shown in the multi-projection display of FIG. A position adjusting device 1 having a device 14 is provided.

  The adjustment image data output device 12, the evaluation value calculation device 13, and the position adjustment control device 14 of the projection image position adjustment device 1 have the same components as in FIG. 2, but in the first embodiment of the present invention. The evaluation value calculation process of the evaluation value calculation unit 133 in the evaluation value calculation device 13 is partly different from the evaluation value calculation process used in the basic method for adjusting the position of the projected image described above.

  In other words, in the projection image position adjustment method according to the first embodiment of the present invention, the evaluation value calculation process is performed in consideration of the above-mentioned “rear projection screen characteristics No. 1 and No. 2”. Evaluation value calculation processing in the projected image position adjustment method according to the first embodiment of the present invention will be described later.

  The rear projection type multi-projection display shown in FIG. 7 and the projected image position adjustment apparatus 1 shown in FIG. 2 can be used not only in the first embodiment but also in the second to fourth embodiments described later. However, the third and fourth embodiments differ in that the two projectors PJ1 and PJ2 shown in FIG. 7 are arranged in the vertical direction.

  Next, a method for adjusting the position of the projected image according to the first embodiment will be described. The position adjustment operation in the method for adjusting the position of the projected image according to the first embodiment is also the same as the basic method for adjusting the position of the projected image described above.

  That is, first, the user adjusts the position of the two adjustment images CG1 and CG2 within a possible range by manual operation, and the position set by the position adjustment by manual operation by the user is used as the basic projected image described above. Similar to the position adjustment method, the initial position is called. Then, from this initial position, a position where the adjustment image CG2 projected by the projector PJ2 is moved 10 pixels in the vertical direction (upward) is set as a processing start position, and the adjustment image CG2 is moved downward from this processing start position. The operation of sequentially moving 20 pixels by 1 pixel unit is performed.

  As described above, since the operation for adjusting the position is the same as the basic method for adjusting the position of the projected image described above, the above-described “rear projection screen characteristics No. 1 and No. 2” are considered here. The evaluated value calculation process will be described.

  Here, in Embodiment 1 and Embodiments 2 to 4 to be described later, the threshold value (RGB = 240, 240, 240) in which the pixel value as the threshold is set in the above-described basic projected image position adjustment method. ) To a value sufficiently lower than. For example, R, G, B = (128, 128, 128) is set, and the number of pixels having pixel values of R, G, B = (128, 128, 128) or more is measured. In each embodiment of the present invention, a pixel equal to or higher than this threshold is referred to as a high luminance pixel, and the number of high luminance pixels is referred to as a high luminance pixel number.

  As described above, the threshold value for determining whether or not the pixel is a high-luminance pixel is sufficiently lower than the threshold value (RGB = 240, 240, 240) used in the above-described basic projection image position adjustment method. The reason why the value is set is that the above-described “rear projection screen characteristic 1” is taken into consideration. The number of high luminance pixels is calculated by the evaluation value calculation unit 133 in FIG.

  The evaluation value calculation unit 133 not only calculates the number of high-luminance pixels at each position but also has a function of calculating the contrast for each position. Next, calculation of contrast for each position will be described. This contrast is used as a parameter for obtaining an evaluation value together with the number of high luminance pixels.

  By the way, in consideration of “rear projection screen characteristic 1”, the threshold value for determining a high luminance pixel (“white” in the basic projection image position adjustment method) is set to a low value. The position can be adjusted with a certain degree of accuracy by obtaining an evaluation value based on the number of pixels that have reached the threshold (the number of high-luminance pixels).

  However, in general, an imaging device used in an imaging device has a low luminance resolution in a dark part, and further, in a low luminance region, the influence of noise emitted from the imaging device itself increases. The rate at which erroneous determination occurs in the determination of high-luminance pixels increases. For this reason, it is difficult to adjust the position with high accuracy in units of one pixel by simply lowering the threshold value. Therefore, in the present invention, contrast is used as a parameter for obtaining an evaluation value together with the number of high luminance pixels.

  It should be noted that the contrast is used as a parameter for obtaining the evaluation value together with the number of high-luminance pixels by utilizing “rear projection screen characteristics 2”. That is, the range of “blur” of the adjustment images CG1 and CG2 is wide when the adjustment images CG1 and CG2 are largely misaligned. From the captured image data obtained by imaging the adjustment images CG1 and CG2 in that state. The resulting contrast is small. On the other hand, in the state where the positional deviation between the adjustment images CG1 and CG2 is small, the “blurred” range of the adjustment images CG1 and CG2 becomes narrow, so that the light concentrates in a narrower range, and the adjustment image CG1 in that state The contrast obtained from the captured image data obtained by imaging CG2 increases. Therefore, the contrast appropriately represents the position adjustment state of the two adjustment images CG1 and CG2.

  The contrast is obtained every time the adjustment image CG2 is moved in units of one pixel from the processing start position described above. That is, in the first embodiment of the present invention, a process of counting high-brightness pixels every time the adjustment image CG2 is moved by 20 pixels in units of pixels from the processing start position, and a process of calculating the contrast at each position I do.

  The contrast at each position is obtained from the difference between the pixel values of the pixel having the maximum pixel value and the pixel having the minimum pixel value in the captured image data captured at each position.

Specifically, in each pixel, the pixel having the maximum value and the pixel having the minimum value obtained by multiplying the pixel values (0 to 255) for each RGB are searched, and the difference between them is determined as the contrast at the position. To do. That is, the maximum pixel value obtained by multiplying the pixel values for each RGB is represented by (R · G · B) _max , and the minimum pixel value obtained by multiplying the pixel values for each RGB is represented by (R · G · B) _max. G · B) If expressed in _min , the contrast C is
C = (R · G · B) _max- (R · G · B) _min (1)
It can be asked.

  For example, in the captured image at a certain position, the pixel values of R, G, B in the pixel having the maximum pixel value are R = 255, G = 255, B = 255, and the pixel having the minimum pixel value If the values are R = 0, G = 0, and B = 0, the contrast C of the captured image at that position is determined as C = (255 × 255 × 255) − (0 × 0 × 0). Can do.

  Here, in the equation (1), when the maximum value and the minimum value of the pixel values are obtained, the respective pixel values of RGB are multiplied to express the difference in pixel values between the pixels more clearly by multiplication. This is because the pixel having the maximum pixel value and the minimum pixel value can be appropriately identified.

  For example, in the captured image data at a certain position, when there are pixels with RGB pixel values of R = 255, G = 255, B = 255 and pixels with R = 255, G = 255, B = 254, these When the pixel values of the former are averaged, the pixel value of the former pixel is 255, and the pixel value of the latter pixel is about 254.666. There is no significant difference between the two pixel values, and whichever is the maximum pixel value. This is because it is difficult to specify whether the pixel has a pixel.

  On the other hand, when each pixel value of RGB is multiplied, the pixel value of the former pixel is 255 × 255 × 255 = 16581375, and the pixel value of the latter pixel is 255 × 255 × 254 = 16516350. Therefore, a large difference can be recognized between both pixel values. For this reason, it is possible to appropriately identify the pixel having the maximum pixel value. The same applies to the case where the pixel having the minimum pixel value is specified.

  The contrast becomes maximum when the two adjustment images CG1 and CG2 overlap each other at an appropriate position. This is because, as described above, when the two adjustment images CG1 and CG2 are appropriately overlapped, the so-called “blur” range is narrow and the light concentrates, so that bright pixels become brighter, and similarly dark pixels Because it is darker because it does not receive other light. On the other hand, if the two adjustment images CG1 and CG2 are not properly overlapped, the range of so-called “blur” is wide and the light is dispersed more widely, resulting in a low contrast.

  FIG. 8 is a diagram illustrating a histogram of pixel values (R × G × B) at each position when the position adjustment operation of the two adjustment images CG1 and CG2 is performed. That is, FIG. 8 shows the relationship between the degree of position adjustment deviation and contrast as a result of the position adjustment operation.

  FIG. 8A shows a state where the two adjustment images CG1 and CG2 are not misaligned and are appropriately aligned (this is expressed as “± 0”), and FIG. 8B shows that the adjustment image CG2 is displayed. FIG. 8C shows a state where one pixel is shifted upward from the adjustment image CG1 (represented as “+1”). FIG. 8C illustrates that the adjustment image CG2 has two pixels upward from the adjustment image CG1. The state is shifted (this is expressed as “+2”). FIG. 8D shows a state in which the adjustment image CG2 is shifted by one pixel in the downward direction with respect to the adjustment image CG1 (this is expressed as “−1”), and FIG. 8E shows the adjustment image. This is a state where CG2 is shifted downward by two pixels with respect to the adjustment image CG1 (this is represented as “−2”).

  8A to 8E, the horizontal axis indicates the pixel value (R × G × B) at each position, and the vertical axis indicates the frequency (number of pixels) of the pixel value (R × G × B). In this case, since it is a rear projection type multi-projection display, there are many dark pixels, that is, pixels with a small pixel value, in the imaging data obtained by imaging the rear projection plane R.

  In FIG. 8, the possible range of the pixel value of each pixel is from R × G × B = 0 to R × G × B = 255 × 255 × 255, that is, a large value from 0 to 16 million or more. However, in FIG. 8, for the convenience of illustration, pixel values are represented in a range of up to 35000 by performing a process for reducing the value.

  Here, since the contrast is expressed by the difference between the maximum pixel value and the minimum pixel value, the wider the distribution of pixel values in the horizontal axis direction, the higher the contrast. That is, as can be seen from FIG. 8, the contrast is lower as the shift between the adjustment images CG1 and CG2 is larger in the vertical direction, and the contrast is highest when there is no position shift (± 0) between the adjustment images CG1 and CG2. Yes.

  For example, in a state (± 0) in which the two adjustment images CG1 and CG2 are not misaligned and appropriately aligned (± 0), the minimum pixel value is 0 and the maximum pixel value is 16920, so the contrast C is 16920. . Further, in a state (+2) in which the adjustment image CG2 is shifted by two pixels upward with respect to the adjustment image CG1, the minimum pixel value is 0 and the maximum pixel value is 11431, so the contrast C is 11431. . Further, in the state (−2) in which the adjustment image CG2 is shifted downward by two pixels with respect to the adjustment image CG1, the minimum pixel value is 0 and the maximum pixel value is 12310. Therefore, the contrast C is 12310. is there.

  Accordingly, the contrast height of the adjustment images CG1 and CG2 at the respective positions can be used as an index for determining whether or not the two adjustment images CG1 and CG2 are appropriately overlapped. That is, as a result of calculating the contrast, the high calculated contrast means that the two adjustment images CG1 and CG2 are more appropriately overlapped.

  As described above, in the operation of aligning the two adjustment images CG1 and CG2 by moving the adjustment image CG2 pixel by pixel, processing for calculating the number of high-luminance pixels and contrast at each position is performed. In the projection image position adjustment method according to the first embodiment, the evaluation value is calculated by the evaluation value calculation unit 133 using the number of high-luminance pixels and the contrast calculated at each position. This evaluation value can be obtained simply by adding the number of high-luminance pixels and contrast, that is, “evaluation value = number of high-luminance pixels + contrast”. In the projection image position adjustment method according to the first embodiment, The evaluation value is calculated by the following procedure.

  There is a large difference between the number of high-luminance pixels described above and the contrast value. That is, as can be seen from the above (1), the contrast value obtained at each position is calculated as the product of the pixel values of the RGB components of each pixel at that position. X0x0-255x255x255 ", that is," 0-16581375 ".

  On the other hand, the possible range of the value of the number of high-luminance pixels is the upper limit of the number of pixels of the image sensor of the camera. For example, when a camera having an image sensor of 1 million pixels is used, it is “0 to 1000000”. . Actually, only a part of the region where the number of high-luminance pixels exceeding the set threshold value is generated, and the maximum value of the number of high-luminance pixels is empirically about 20000 pixels. Therefore, the possible range of the value of the number of high luminance pixels can be considered as “0 to 20000”.

  Thus, there is a maximum difference of about 830 times between the contrast and the number of high-luminance pixels. Therefore, as a first step for calculating an appropriate evaluation value, normalization is performed to align the values of contrast and the number of high luminance pixels.

Specifically, the normalized high luminance pixel number (referred to as normalized high luminance pixel number) is calculated by performing the following processing on the high luminance pixel number. The normalized number of high-intensity pixels is
Normalized number of high brightness pixels = number of high brightness pixels x (maximum value in contrast group / maximum value in number of high brightness pixels) (2)
It shall be expressed as

  Note that the maximum value in the contrast group is, for example, 16920 shown in FIG. 8A as the maximum value in the contrast group obtained at each position shown in FIGS. 8A to 8E in FIG. It will be.

  In the above equation (2), “the maximum value in the contrast group / the maximum value in the high luminance pixel number group” is not limited to the maximum value, but the average value of the contrast group, the average value of the high luminance pixel number group, etc. The value of may be used.

Next, as a second step for calculating an appropriate evaluation value, predetermined weighting coefficients α and β are respectively multiplied to the normalized number of high-luminance pixels subjected to the normalization process and the contrast. That is, the evaluation value used in the embodiment of the present invention is
Evaluation value = α × normalized high luminance pixel number + β × contrast (3)
It is assumed that Note that α and β are not limited to certain numerical values, but here, the contrast is not easily affected by interference factors, and stable measurement results can be obtained even when environmental conditions change to some extent. In consideration of the above, weighting is performed with more emphasis on contrast. Considering this point, α = 1 and β = 5 are set in the projected image position adjustment method according to the first embodiment of the present invention.

  By the way, the above-described expression (3) should be obtained for each position in the position adjustment operation by moving the adjustment image CG2 pixel by pixel. However, the “maximum value in the contrast group / maximum value in the high-luminance pixel number group” in the above-described equation (2) is not obtained for each position in the position adjustment operation. It can be obtained only when the contrast and the number of high luminance pixels are calculated. Accordingly, at each position in the position adjustment operation, the contrast and the number of high-luminance pixels at that position are provisionally stored in the position / evaluation value storage unit 134 of the evaluation value calculation device 13 in FIG. 2 in association with each position. Then, after the contrast and the number of high-luminance pixels at all positions are calculated, the evaluation value at each position is obtained by applying the above-described equation (3) to the temporarily stored contrast and the number of high-luminance pixels. The calculated evaluation value is associated with each position and stored again in the position / evaluation value storage unit 134 of the evaluation value calculation apparatus 13 in FIG.

  Then, the position / evaluation value acquisition unit 143 of the position adjustment control device 14 in FIG. 2 maximizes the position having the maximum evaluation value from the contents stored in the position / evaluation value storage unit 134 of the evaluation value calculation device 13. Acquired as a position, and the acquired maximum evaluation position is stored in the maximum evaluation position storage unit 142. For example, if the position having the maximum evaluation value is “8”, the position “8” is stored in the maximum evaluation position storage unit 142 as the maximum evaluation position.

  That is, when the adjustment image CG2 is set to the maximum evaluation position “8”, each line of the adjustment image CG1 and each line of the adjustment image CG2 are superimposed in an optimum projection position relationship in the vertical direction. If projection is performed by the projectors PJ1 and PJ2 in that positional relationship, each projected image is projected at the optimum projection position in the vertical direction.

  Therefore, the position adjustment is performed so that the maximum evaluation position is the projection position of the projection image of the projector PJ2. As a result, the projected images of the projectors PJ1 and PJ2 become optimum projection positions that have been appropriately adjusted in the vertical direction, and high-quality images that do not cause discontinuous seams or blurs in the overlapping region. Can be displayed.

  In addition, the resolution of the imaging device 11 used in the method for adjusting the position of a projected image according to each embodiment of the present invention is 1280 pixels horizontal × 1024 pixels vertical, even if it has a relatively low resolution of around 1 million pixels. The position of a projected image with a higher resolution than that (here, the resolution of one projector is horizontal 1280 × vertical 720) can be adjusted in units of one pixel.

  FIG. 9 is a flowchart schematically showing a procedure for adjusting the position of the projected image in the method for adjusting the position of the projected image according to the first embodiment. Since the processing of the individual steps in FIG. 9 has already been described, the overall processing flow will be briefly described here.

  First, the adjustment images CG1 and CG2 are projected onto the rear projection screen SCR 'by the projectors PJ1 and PJ2 (step S1). The user adjusts the position of the adjustment images CG1 and CG2 projected by the projectors PJ1 and PJ2 within a possible range by manual operation, and then adjusts one of the adjustment images CG1 and CG2 (adjustment). Is set to the processing start position “1” (step S2). In this state, the adjustment image projected on the rear projection surface R of the rear projection screen SCR ′ by the imaging device 11 is set. CG1 and CG2 are imaged (step S3).

  Next, the contrast and the number of high luminance pixels are calculated from the captured image data obtained by imaging (step S4), and the calculated contrast and the number of high luminance pixels are stored in association with the position at that time (step S5). .

  Then, the position is incremented (step S6), and it is determined whether or not the position after the increment exceeds the maximum movement position (“20” in the first embodiment) (step S7). Then, the process returns to step S3, and the processes after step S3 are performed. On the other hand, if the maximum movement position is exceeded, the evaluation value at each position is calculated by applying the above-described equation (3) to the contrast and the number of high-luminance pixels recorded in step S5, And the evaluation value is acquired (step S8), and the position having the maximum evaluation value is stored in the maximum evaluation position storage unit 142 as the maximum evaluation position (step S9).

  Then, control unit 144 adjusts the position of projector PJ2 so that the maximum evaluation position is the projection position of the projection image of projector PJ2. As a result, the projected images of the projectors PJ1 and PJ2 have an optimal positional relationship in the vertical direction.

  As described above, according to the first embodiment, the evaluation value for each position is calculated by the above-described equation (3) using the number of high luminance pixels and the contrast obtained for each position. . Thus, by calculating the evaluation value using the number of high-luminance pixels and the contrast, it is possible to obtain an optimal evaluation value in consideration of the “rear projection screen characteristics 1 and 2” as described above. .

  Further, by calculating an evaluation value using the number of high-luminance pixels and contrast, an evaluation value that is not easily affected by various interference factors such as the exposure setting of the imaging device 11 and the illumination conditions of the space where the multi-projection display is installed is obtained. Obtainable.

  10 and 11 are diagrams illustrating the relationship between the position adjustment operation of the adjustment image when the exposure setting of the imaging device 11 that is one of the interference factors is changed, and the evaluation value at that time. In FIG. 10, the horizontal axis represents the position, and the vertical axis represents the evaluation value. 10 shows the case where only the number of high luminance pixels is used as the evaluation value, and FIG. 11 shows the case where the evaluation value is calculated using the number of high luminance pixels and the contrast. ”,“ 64 ”,“ 80 ”,“ 96 ”,“ 112 ”,“ 128 ”. 10 and 11 are obtained by experiments different from those in FIG. 6. In FIGS. 10 and 11, the adjustment images CG1 and CG2 are appropriately aligned when the position is “6”. Suppose that it is in a state.

  As can be seen from FIG. 10, when only the number of high-luminance pixels is used as an evaluation value, when the exposure setting of the camera is low (in the example of FIG. 10, exposure settings “48”, “64”, etc.) The position when the number of pixels is the maximum, that is, the maximum evaluation value is “6”, and the correspondence between the maximum evaluation value and an appropriate position can be taken. However, when the exposure setting of the camera becomes high (in the example of FIG. 10, the exposure setting “ 80 ”or higher), and the number of high-luminance pixels is the maximum, that is, the maximum evaluation value at a position other than the position“ 6 ”, and erroneous alignment is performed. In this example, the positional deviation is at most about two pixels, but the present invention aims at performing highly accurate positional adjustment in units of one pixel, and thus the positional deviation of two pixels is out of the allowable range.

  On the other hand, when the evaluation value is calculated using the number of high-luminance pixels and the contrast, as shown in FIG. 11, not only when the camera exposure setting is low, but also when the camera exposure setting is high, The position at the time of the maximum evaluation value (evaluation value calculated by the expression (3)) is “6”. As described above, being unaffected by the exposure setting of the imaging device 11 means that it is not easily affected by changes in illumination of a space in which the multi-projection display is used, and is not easily affected by so-called interference factors. It shows that highly accurate position adjustment can be performed.

  In the projection image position adjustment method according to the first embodiment described above, the position of the adjustment image CG2 is obtained by fixing the adjustment image CG1 and moving the adjustment image CG2 among the adjustment images CG1 and CG2. However, on the contrary, of course, the adjustment image CG2 may be fixed and the adjustment image CG1 may be moved.

[Embodiment 2]
In the projection image position adjustment method according to the first embodiment described above, the case where the vertical image (vertical direction) position adjustment of the respective projection images from the two projectors PJ1 and PJ2 arranged in the horizontal direction has been described. In the method for adjusting the position of the projected image according to the second embodiment, the position adjustment in the horizontal direction (left and right direction) of the respective projected images from the two projectors PJ1 and PJ2 arranged in the horizontal direction will be described.

  FIG. 12 is a diagram schematically showing an example of the adjustment images CG3 and CG4 projected separately from the two projectors PJ1 and PJ2 arranged in the horizontal direction onto the rear projection surface R of the rear projection screen SCR ′. It is. As the adjustment images in this case, adjustment images CG3 and CG4 as shown in FIGS. 12A and 12B are used.

  The adjustment image data CGD3 and CGD4 corresponding to the adjustment images CG3 and CG4 are generated by the adjustment image data generation unit 121 shown in FIG. Then, the adjustment image data CGD3 and CGD4 generated by the adjustment image data generation unit 121 are given to the projectors PJ1 and PJ2 by the adjustment image data output unit 122, so that the rear projection of the rear projection screen SCR ′ is performed. On the surface R, adjustment images CG3 and CG4 as shown in FIG. 12 are projected.

  These adjustment images CG3 and CG4 are also predetermined in the overlapping region when the adjustment images CG3 and CG4 are projected onto the rear projection screen SCR ′ in an appropriate positional relationship, similarly to the adjustment images CG1 and CG2. It has a pattern in which the features of It is assumed that the adjustment images CG3 and CG4 have a pattern made up of line drawings in the vertical direction. Note that the thickness (width) of line drawings, the interval between line drawings, and the like are the same as those of the adjustment images CG1 and CG2 (see the broken line frame in FIG. 12).

  FIG. 13 is a diagram schematically showing a state in which the adjustment images CG3 and CG4 shown in FIG. 12 are partially projected on the rear projection surface R of the rear projection screen SCR ′. As shown in FIG. 13, an adjustment image CG3 by the projector PJ1 and an adjustment image CG4 by the projector PJ2 partially overlap each other on the rear projection plane R of the rear projection screen SCR ′. Projected. Note that the adjustment image CG3 and the adjustment image CG4 in FIG. 13 are in a state before the position adjustment is performed.

  Also in the projection image position adjustment method according to the second embodiment, one of the two adjustment images CG3 and CG4 (the adjustment image CG3 projected by the projector PJ1) is fixed and the other adjustment image is used. It is assumed that the optimum projection position is detected by moving an image (adjustment image CG4 projected by the projector PJ2) in the horizontal direction (left-right direction) on the rear projection screen SCR ′. The adjustment image CG4 can be easily moved in units of pixels by using a function that can move the position of the effective image display area of the image forming area in the liquid crystal modulation device of the projector PJ2 in units of pixels. .

  The projected image position adjustment method according to the second embodiment can be performed using the projected image position adjustment device 1 (see FIG. 2) in substantially the same procedure as the projected image position adjustment method according to the first embodiment. So here is a brief description.

  First, the user adjusts the adjustment images CG4 projected by the projector PJ2 in the horizontal direction (from the left direction to the left direction) after the user has adjusted the position of the adjustment images CG3, CG4 projected by the projectors PJ1, PJ2 within a range that can be manually operated. The position moved by 10 pixels is set as the processing start position, and the adjustment image CG4 is sequentially moved from the processing start position to the right by 20 pixels in units of one pixel. Note that processing for setting an optimal projection position, such as an evaluation value calculation method, can be performed in the same manner as described in the first embodiment, and thus description thereof is omitted.

  The procedure for adjusting the position of the projected image in the method for adjusting the position of the projected image according to the second embodiment is the same as the adjustment images CG1 and CG2 in the flowchart of FIG. 9 used in the description of the method for adjusting the position of the projected image according to the first embodiment. Is replaced with the adjustment images CG3 and CG4, the flowchart of FIG. 9 can be applied.

  In the projected image position adjustment method according to the second embodiment, the position of the adjustment image CG4 is determined by fixing the adjustment image CG3 and moving the adjustment image CG4 among the adjustment images CG3 and CG4. However, on the contrary, of course, the adjustment image CG4 may be fixed and the adjustment image CG3 may be moved.

[Embodiment 3]
In the projection image position adjustment method according to the first and second embodiments described above, the vertical direction (up and down direction) and the horizontal direction (left and right direction) of the respective projection images from the two projectors PJ1 and PJ2 arranged in the horizontal direction. ), The horizontal position of each projection image from the two projectors PJ1 and PJ2 arranged in the vertical direction by the adjustment images CG3 and CG4 used in the description of the second embodiment. Adjustments can also be made.

  Hereinafter, the horizontal position adjustment of the projected images from the two projectors PJ1 and PJ2 arranged in the vertical direction by the adjustment images CG3 and CG4 will be described.

  The rear projection type multi-projection display to which the projection image position adjustment method according to the third embodiment is applied differs from FIG. 1 in that the two projectors PJ1 and PJ2 shown in FIG. 1 are installed side by side in the vertical direction. Therefore, the configuration of the rear projection multi-projection display to which the projection image position adjustment method according to the third embodiment is applied is not shown.

  The projector PJ1 projects a projection image in the vertical direction on the rear projection plane R of the rear projection screen SCR ′, and the projector PJ2 projects in the vertical direction on the rear projection plane R of the rear projection screen SCR ′. Projected images are projected. In addition, the projected images from the projectors PJ1 and PJ2 are tiling projected on the rear projection screen SCR 'so as to partially have an overlapping region.

  FIG. 14 is a diagram schematically showing an example of adjustment images CG3 and CG4 separately projected on the rear projection screen SCR 'from two projectors PJ1 and PJ2 arranged in the vertical direction. FIG. 14 (a) shows the adjustment image CG3, and FIG. 14 (b) shows the adjustment image CG4.

  FIG. 15 is a diagram schematically showing a state in which the adjustment images CG3 and CG4 shown in FIG. 14 are projected on the rear projection screen SCR 'with a partly overlapping region. As shown in FIG. 15, an adjustment image CG3 by the projector PJ1 and an adjustment image CG4 by the projector PJ2 are projected on the rear projection screen SCR 'with a partial overlapping area. Note that the adjustment image CG3 and the adjustment image CG4 in FIG. 15 are in a state before the position adjustment is performed.

  Also in the method for adjusting the position of the projected image according to the third embodiment, one of the two adjustment images CG3 and CG4 (the adjustment image CG3 projected by the projector PJ1) is fixed and the other adjustment image is used. The optimal projection position is detected by moving an image (adjustment image CG4 projected by the projector PJ2) in the horizontal direction (left-right direction) on the rear projection screen SCR ′.

  The method for adjusting the position of the projected image according to the third embodiment can be performed using the projected image position adjusting apparatus 1 (see FIG. 2) in substantially the same procedure as the method for adjusting the position of the projected image according to the first embodiment. So here is a brief description.

  First, the user adjusts the adjustment images CG4 projected by the projector PJ2 in the horizontal direction (from the left direction to the left direction) after the user has adjusted the position of the adjustment images CG3, CG4 projected by the projectors PJ1, PJ2 within a range that can be manually operated. The position moved by 10 pixels is set as the processing start position, and the adjustment image CG4 is sequentially moved from the processing start position to the right by 20 pixels in units of one pixel. Note that processing for setting an optimal projection position, such as an evaluation value calculation method, can be performed in the same manner as described in the first embodiment, and thus description thereof is omitted.

  The procedure for adjusting the position of the projected image in the method for adjusting the position of the projected image according to the third embodiment is the same as the adjustment images CG1 and CG2 in the flowchart of FIG. 9 used in the description of the method for adjusting the position of the projected image according to the first embodiment. Is replaced with the adjustment images CG3 and CG4, the flowchart of FIG. 9 can be applied.

  In the projected image position adjustment method according to the third embodiment, the position of the adjustment image CG4 is determined by fixing the adjustment image CG3 and moving the adjustment image CG4 among the adjustment images CG3 and CG4. However, on the contrary, of course, the adjustment image CG4 may be fixed and the adjustment image CG3 may be moved.

[Embodiment 4]
In the projection image position adjustment method according to the third embodiment described above, the case has been described in which the position adjustment in the horizontal direction (left-right direction) of each projection image from the two projectors PJ1 and PJ2 arranged in the vertical direction is performed. By using the adjustment images CG1 and CG2 used in the description of the first embodiment, the position adjustment in the vertical direction (vertical direction) of each projection image from the two projectors PJ1 and PJ2 arranged in the vertical direction is performed. You can also.

  FIG. 16 shows a state in which the adjustment images CG1 and CG2 are projected from the two projectors PJ1 and PJ2 arranged in the vertical direction onto the rear-side projection surface R of the rear projection screen SCR ′ with a partly overlapping region. FIG. Note that the adjustment image CG1 and the adjustment image CG2 in FIG. 16 are in a state before the position adjustment is performed.

  Note that in the projection image position adjustment method according to the fourth embodiment, the adjustment image CG1 projected by the projector PJ1 is fixed out of the two adjustment images CG1 and CG2, and the adjustment image CG2 projected by the projector PJ2 is rear-mounted. It is assumed that the optimum projection position is detected by moving in the vertical direction (up and down direction) on the projection screen SCR ′.

  Then, the adjustment image CG2 projected by the projector PJ2 is set in the vertical direction (upward and downward) from the state in which the user has adjusted the position of the adjustment images CG1 and CG2 projected by the projector PJ1 and PJ2 within a range that can be manually operated. The position moved by 10 pixels is set as the processing start position, and the adjustment image CG2 is sequentially moved from the processing start position by 20 pixels in units of one pixel downward. Note that processing for setting an optimal projection position, such as an evaluation value calculation method, can be performed in the same manner as described in the first embodiment, and thus description thereof is omitted.

  Note that the procedure for adjusting the position of the projected image in the method for adjusting the position of the projected image according to the fourth embodiment can apply the flowchart of FIG. 9 used in the description of the method for adjusting the position of the projected image according to the first embodiment.

  In the projected image position adjustment method according to the fourth embodiment, the position of the adjustment image CG2 is determined by fixing the adjustment image CG1 and moving the adjustment image CG2 among the adjustment images CG1 and CG2. However, on the contrary, of course, the adjustment image CG2 may be fixed and the adjustment image CG1 may be moved.

  As described above, the adjustment images CG1 and CG2 and the adjustment images CG3 and CG4 are arranged in the horizontal direction and the vertical direction in the rear projection type multi-projection display as described in the first to fourth embodiments. Position adjustment in the horizontal direction and the vertical direction with respect to the projection images from the two projectors PJ1 and PJ2 can be performed at high speed and with high accuracy.

  That is, by using the adjustment images CG1 and CG2 for the projection images from the two projectors PJ1 and PJ2, the vertical position adjustment of the two projectors PJ1 and PJ2 arranged in the horizontal direction and the vertical direction is performed. It can be performed at high speed and with high accuracy, and by using the adjustment images CG3, CG4, the horizontal position adjustment of each of the two projectors PJ1, PJ2 arranged in the horizontal direction and the vertical direction can be performed at high speed and with high accuracy. Can be done.

  Then, by appropriately combining the projection image position adjustment methods according to the first to fourth embodiments as necessary, m projectors in the horizontal direction and n projectors in the vertical direction and n projectors in the vertical direction are used. In the rear projection type multi-projection display, the position of each projection image of each projector can be adjusted at high speed and with high accuracy.

  For example, FIG. 17 shows a rear projection type multi-projection display having a total of 16 projectors PJ1, PJ2,... Also, by performing the position adjustment operation as described in the method for adjusting the position of the projected image according to the first to fourth embodiments, a set of two projectors arranged adjacent to each other in the horizontal direction and the vertical direction, Position adjustment of the projected images of all projectors can be performed in a short time and with high accuracy.

  The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present invention. For example, in each of the above-described embodiments, the case where the projection image from each projector PJ1, PJ2 is tiling projected on the rear projection screen SCR ′ has been described. However, not only the tiling projection but also each projector PJ1, PJ2 This can also be applied to so-called stacking projection in which the projected images are superimposed on the same projection area.

  In the above-described embodiments, for the first color in the adjustment image CG1, the pixel values (gradation values) of the color components of R (red), G (green), and B (blue) are set as R = 255, G = 160, and B = 0. For the second color in the adjustment image CG2, the pixel values of the R (red), G (green), and B (blue) color components are R = 0. G = 160 and B = 255, but when the two adjustment images are projected in an appropriate positional relationship, a captured image obtained by photographing the rear projection surface R of the rear projection screen SCR ′. The pixel values of the two adjustment images CG1 and CG2 are not limited to the aforementioned values, as long as a predetermined feature can be acquired in the data.

  Further, in each of the above-described embodiments, the threshold value of the pixel value for determining as a high-luminance pixel is set to “128, 128, 128”. Optimum values can be set according to environmental conditions such as characteristics and lighting.

  Further, although the interval between the lines in the adjustment images CG1 and CG2 and the adjustment images CG3 and CG4 is 20 pixels, this is not limited to 20 pixels, but it is preferable that the interval is 10 pixels or more.

  In addition, it is preferable that the evaluation value is calculated by performing imaging a plurality of times in a state where the two adjustment images have the same positional relationship, and calculating the evaluation value using the plurality of imaging data. As described above, by calculating the evaluation value using the captured image data obtained by a plurality of times of imaging, it is possible to obtain a highly accurate evaluation value in which the influence of noise of the imaging device is reduced. In this case, it is conceivable that an average value of evaluation values calculated using captured image data obtained by a plurality of times of imaging is obtained and the average value is set as an evaluation value to be obtained.

  In each of the above-described embodiments, the position adjustment is performed for two projectors out of a plurality of projectors. However, this means that the position adjustment is performed with at least two projectors as one set. It also includes simultaneously adjusting the position of the projected images from a plurality of projectors or a plurality of sets of projectors.

  For example, in the case of a multi-projection display using 2 × 2 4 projectors, the upper two projectors are set as one set, and the horizontal position adjustment of the projected image from the upper set of projectors is made At the same time, it is possible to set the two projectors in the lower stage as a set and adjust the position of the projected image from the lower set of projectors in the horizontal direction. In this way, by adjusting the position of the projection images from a plurality of projectors or a plurality of sets of projectors at the same time, when the multi-projection display is composed of a large number of projectors as shown in FIG. The position adjustment time can be greatly shortened.

  In each of the above-described embodiments, an example is described in which position adjustment is performed by obtaining an evaluation value based on captured image data obtained by capturing an image projected on the rear projection surface R of the rear projection screen SCR ′. Although it demonstrated, it is not restricted to this, For example, it can be used also for the rear projection type multi-projection display which uses a reflecting mirror in order to earn a projection distance in order to make depth small. In this case, it is also possible to use a half mirror as a reflecting mirror, install a camera on the back side of the half mirror, and perform position adjustment using the captured image.

  Thus, according to the present invention, when the position adjustment of a plurality of projection images is performed using two adjustment images, the final projection image of the two adjustment images (for example, in a rear projection type multi-projection display). Rather than using a picked-up image obtained by picking up an image displayed on the front-side display surface F of the rear projection screen SCR ′), it picks up a projected image at an arbitrary cross section on the optical path of the projected image. Position adjustment is performed based on the obtained captured image data.

  The projector used in each of the above-described embodiments has been described assuming a three-plate projector of RGB three primary colors, but the present invention can also be applied to a projector of a multi-primary color type having four or more primary colors. .

  In each of the above-described embodiments, the projectors are physically arranged in the horizontal direction or the vertical direction in order to arrange (project) the projection images from the plurality of projectors in the horizontal direction or the vertical direction. Of course, a projection position changing function such as lens shift may be used instead of changing the target position.

  Further, in each of the above-described embodiments, the adjustment images CG1 and CG2 and the adjustment images CG3 and CG4 are formed using a pattern composed of horizontal and vertical straight lines. However, the adjustment images CG1 and CG2 and the adjustment image CG3 are used. As the pattern of CG4, various patterns can be used as long as they have line drawings.

  FIG. 18 is a diagram showing a modification (part 1) of the adjustment image pattern, FIG. 19 is a diagram showing a modification (part 2) of the adjustment image pattern, and FIG. 20 is a modification of the adjustment image pattern (part 2). It is a figure which shows the 3).

  FIG. 18A shows an example of an adjustment image made up of a straight line pattern having an inclination, and FIGS. 18B and 18I show adjustment images made up of a pattern having periodicity between the lines. In FIG. 18C, (i) and (ii) are examples of an adjustment image made up of a curved pattern, and FIG. 18D is an example of an adjustment image made up of a broken line pattern.

  FIG. 19A shows an example of an adjustment image made up of a pattern having periodicity in the thickness of the line, FIG. 19B shows an example of an adjustment image made up of a pattern based on a figure, and FIG. FIG. 19D shows an example of an adjustment image made up of a pattern with characters, FIG. 19D shows an example of an adjustment image made up of a pattern in which the length or pattern of adjacent lines is changed, and FIG. It is an example of the image for adjustment.

  20A shows an example of an adjustment image made up of a pattern having a gradation on a line, FIG. 20B shows an example of an adjustment image made up of a pattern in which colors are changed in the vertical direction of the same line, and FIG. (C) is an example of the image for adjustment which consists of the pattern which made the color differ by the adjacent line.

  In addition to those shown in FIGS. 18 to 20, for example, a pattern in which the color is inverted, a pattern in which the color is changed on the time axis, a pattern in which the shape is changed on the time axis, these various patterns, and FIG. Various patterns such as a pattern formed by combining FIG. 20 can be used as the adjustment image.

  It is also possible to create a projected image position adjustment program in which the processing procedure for realizing the present invention described above is described, and to record the projected image position adjustment program on various recording media. Accordingly, the present invention also includes a recording medium on which the projected image position adjustment program is recorded. Further, a position adjustment program for the projected image may be obtained from the network.

The figure which shows the structure of a multi-projection display of a front projection type. The figure which shows the structure of the position adjustment apparatus 1 of a projection image in detail. The figure which shows typically an example of adjustment image CG1, CG2 separately projected on the screen SCR from two projectors PJ1, PJ2 arranged in the horizontal direction. FIG. 4 is a diagram schematically showing a state in which adjustment images CG1 and CG2 shown in FIG. 3 are partially projected and projected on a screen SCR. The figure which expands and shows the superimposition area | region of adjustment image CG1, CG2 in the captured image data from the imaging device 11 in each position of the adjustment image CG2. The figure which shows the pixel count determined as white in each position from the process start position "1" to the position "20" moved by 20 pixels. 1 is a diagram illustrating a configuration of a rear projection multi-projection display to which a projection image position adjustment method according to a first embodiment of the present invention is applied. FIG. The figure which shows the histogram of the brightness | luminance (RxGxB) in each position at the time of performing position adjustment operation of the two images for adjustment CG1, CG2. 5 is a flowchart schematically showing a position control procedure of a projected image in the projected image position adjustment method according to the first embodiment. The figure which shows the relationship between the position adjustment operation of the image for adjustment when changing the exposure setting of the camera which is one of the interference factors, and the evaluation value at that time (evaluation value only by a high-intensity pixel). The figure which shows the relationship between position adjustment operation of the image for adjustment when changing the exposure setting of the camera which is one of the interference factors, and the evaluation value at that time (evaluation value calculated using a high-intensity pixel and contrast) . The figure which shows typically an example of adjustment image CG3, CG4 each separately projected on the screen SCR 'for rear projection from the two projectors PJ1, PJ2 arranged in the horizontal direction. FIG. 13 is a diagram schematically showing a state in which the adjustment images CG3 and CG4 shown in FIG. 12 are projected on the rear projection screen SCR 'with a partial overlapping region. The figure which shows typically an example of adjustment image CG3, CG4 separately projected on the screen SCR 'for rear projection from the two projectors PJ1, PJ2 arranged in the perpendicular direction. FIG. 15 is a diagram schematically illustrating a state in which the adjustment images CG3 and CG4 illustrated in FIG. 14 are projected onto the rear projection screen SCR ′ with a partial overlapping region. FIG. 4 is a diagram schematically showing a state in which adjustment images CG1 and CG2 are partially projected from two projectors PJ1 and PJ2 arranged in the vertical direction onto a rear projection screen SCR ′. The figure which shows the rear projection type multi-projection display which has a total of 16 projectors of 4 units | sets x 4 units | sets. The figure which shows the modification (the 1) of the pattern of the image for adjustment. The figure which shows the modification (the 2) of the pattern of the image for adjustment. The figure which shows the modification (the 3) of the pattern of the image for adjustment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Projection image position adjustment apparatus, 11 ... Imaging apparatus, 12 ... Adjustment image data output apparatus, 13 ... Evaluation value calculation apparatus, 14 ... Position adjustment control apparatus, CG1, CG2 , CG3, CG4 ... adjustment image, PJ1, PJ2 ... projector, SCR '... rear projection screen, F ... front side display surface, R ... rear side projection surface

Claims (17)

A projected image position adjusting method for adjusting positions of two projected images projected on a screen so as to have an overlapping area from two projectors in a multi-projection display having a plurality of projectors, using two adjustment images. ,
Two pieces of adjustment image data corresponding to the two adjustment images having a pattern in which a predetermined feature appears in the superposition region when the two adjustment images are projected in an appropriate positional relationship. A first step for two projectors;
Imaging obtained by photographing the two adjustment images at a predetermined position between the two projectors and the viewer-side display surface when the two adjustment images are projected from the two projectors A second step of calculating an evaluation value associated with the feature based on image data;
A third step of adjusting the position of the two projected images based on the evaluation value;
Have
The feature is a pixel value in the captured image data,
The evaluation value is calculated based on the number of pixels having the pixel value equal to or greater than a threshold value and the difference between the pixel value of each pixel having the maximum pixel value and the pixel having the minimum pixel value. And calculated using
In the third step, the position of the two projected images is adjusted with the position where the evaluation value is maximized as the optimum projection position of the two projected images . In the projection image position adjustment method according to claim 1,
In the second step, at least one of the two adjustment images is moved in the horizontal direction or the vertical direction in units of pixels, and the evaluation value is calculated each time the adjustment image is moved in units of pixels. A method for adjusting a position of a projected image, comprising calculating the position. In the projected image position adjustment method according to claim 1 or 2,
The method for adjusting a position of a projected image, wherein the pattern has a line drawing having a width corresponding to one pixel. In the projection image position adjustment method according to claim 1,
The projected image position adjustment method, wherein the threshold value is set to a value corresponding to a color that appears only when the patterns in the two adjustment images overlap. In the position adjustment method of the projected image according to claim 1,
The projected image position adjustment method, wherein a value obtained by a product of each color component constituting the captured image data is used as the pixel value of each pixel. In the position adjustment method of the projected image according to any one of claims 4-5,
The projection image position adjustment method, wherein the evaluation value is obtained based on a sum of the number of pixels equal to or greater than the threshold value and the contrast. The method for adjusting the position of a projected image according to claim 6 ,
A method for adjusting the position of a projected image, wherein normalization of the number of pixels equal to or greater than the threshold and the contrast is performed. In the projected image position adjustment method according to claim 7 ,
A method for adjusting a position of a projected image, wherein weighting is performed so that the contrast is more reflected in the evaluation value. In the projection image position adjustment method according to any one of claims 1 to 8 ,
In the two adjustment images, one adjustment image has a first pattern of a first color,
The other adjustment image has a second pattern of a second color, and the first color and the second color are the predetermined colors when the first pattern and the second pattern overlap each other. A projected image position adjustment method, wherein values of a red component, a green component, and a blue component in each of the two adjustment images are set so that a feature appears. In the projected image position adjustment method according to any one of claims 1 to 9 ,
In the second step, the evaluation value is calculated by performing photographing a plurality of times in a state where the two adjustment images have the same positional relationship. In the position adjustment method of the projected image according to any one of claims 1-10,
In the third step, the position of the two projected images is adjusted by moving the position of the effective image display area of the image forming area in the electro-optic modulation device of one of the two projectors in units of pixels. A method for adjusting the position of a projected image characterized by the above. In the position adjustment method of the projected image according to any one of claims 1 to 11
The multi-projection display is a rear projection multi-projection display, and the captured image data is projected on the opposite side of the viewer-side display surface in a rear projection screen used in the rear projection multi-projection display. A method for adjusting a position of a projected image, which is image data obtained by capturing the adjustment image projected on a surface. A projection image position adjustment device that adjusts the position of two projection images projected on a screen from two projectors in a multi-projection display having a plurality of projectors using two adjustment images. ,
Two pieces of adjustment image data corresponding to the two adjustment images having a pattern in which a predetermined feature appears in the superposition region when the two adjustment images are projected in an appropriate positional relationship. Image data output device for adjustment that can be output to two projectors;
Imaging obtained by photographing the two adjustment images at a predetermined position between the two projectors and the viewer-side display surface when the two adjustment images are projected from the two projectors An evaluation value calculation device for calculating an evaluation value associated with the feature based on image data;
A position adjustment control device that adjusts the position of the two projected images based on the evaluation value ;
The feature is a pixel value in the captured image data,
The evaluation value is calculated based on the number of pixels having the pixel value equal to or greater than a threshold value and the difference between the pixel value of each pixel having the maximum pixel value and the pixel having the minimum pixel value. And calculated using
Wherein the position adjustment control unit, the position adjusting device of the projected image in which the evaluation value is characterized that you adjust the position of the two projection images the position where the maximum as the optimum projection position of the two projected images. A projected image position adjustment program for adjusting the positions of two projected images projected on a screen so as to have an overlapping area from two projectors in a multi-projection display having a plurality of projectors using two adjustment images There,
Two pieces of adjustment image data corresponding to the two adjustment images having a pattern in which a predetermined feature appears in the superposition region when the two adjustment images are projected in an appropriate positional relationship. A first step for two projectors;
Imaging obtained by photographing the two adjustment images at a predetermined position between the two projectors and the viewer-side display surface when the two adjustment images are projected from the two projectors A second step of calculating an evaluation value associated with the feature based on image data;
A third step of adjusting the position of the two projected images based on the evaluation value ,
The feature is a pixel value in the captured image data,
The evaluation value is calculated based on the number of pixels having the pixel value equal to or greater than a threshold value and the difference between the pixel value of each pixel having the maximum pixel value and the pixel having the minimum pixel value. And calculated using
The third step, the position adjustment program of the projected image of the evaluation value, characterized that you adjust the position of the two projection images the position where the maximum as the optimum projection position of the two projected images. A multi-projection display having a plurality of projectors, and capable of projecting onto a screen such that projected images from the plurality of projectors have an overlapping region;
Two pieces of adjustment image data corresponding to the two adjustment images having a pattern in which a predetermined feature appears in the superposition region when the two adjustment images are projected in an appropriate positional relationship. Image data output device for adjustment that can be output to two projectors;
Imaging obtained by photographing the two adjustment images at a predetermined position between the two projectors and the viewer-side display surface when the two adjustment images are projected from the two projectors An evaluation value calculation device for calculating an evaluation value associated with the feature based on image data;
A position adjustment control device that adjusts the position of the two projected images based on the evaluation value ;
The feature is a pixel value in the captured image data,
The evaluation value is calculated based on the number of pixels having the pixel value equal to or greater than a threshold value and the difference between the pixel value of each pixel having the maximum pixel value and the pixel having the minimum pixel value. And calculated using
The positioning control device, a multi-projection display the evaluation value is characterized that you adjust the position of the two projection images the position where the maximum as the optimum projection position of the two projected images. The multi-projection display according to claim 15 ,
A multi-projection display configured to be capable of tiling projection on a screen such that a plurality of projection images from the plurality of projectors have an overlapping region. The multi-projection display according to claim 15 ,
A multi-projection display configured to be capable of stacking projection on a screen such that a plurality of projection images from the plurality of projectors have an overlapping region.