JP2006010416A - Device and method for measuring three-dimensional shape - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To decrease code search errors while increasing measurement point density. <P>SOLUTION: Two stripe patterns are stored in a frame memory 110. The stripe patterns are changed over by a pattern changeover portion 190, the two stripe patterns are projected continuously, and respective images of the projected stripe patterns are photographed and two photographed images are obtained. Edge extraction processing and code attaching processing to the respective photographed images are performed, and two sets of coded edge images are acquired. The obtained two sets of coded edge images are superposed, and an integrated coded edge image high in edge density and excellent in code distribution is acquired. By carrying out computation of distance measurement with respect to the found integrated coded edge image, generation of errors caused by algorithm can be reduced more when distance calculation is performed, than in the case where distance calculation is performed with respect to each of the plurality of coded edge images. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a three-dimensional shape measurement technique for acquiring distance information to a target object using a pattern projection method.

  As a method for measuring the shape of an object, a method called a pattern projection method is used in which a reference pattern is projected onto an object, and photographing is performed with a CCD camera or the like from a direction different from the direction in which the reference pattern light is projected. There is. In this method, the photographed pattern is deformed depending on the shape of the object. By associating the photographed deformation pattern with the projected pattern, three-dimensional measurement of the object can be performed. The problem with the pattern projection method is how to make the correspondence between the deformed pattern and the projected pattern simple and easy to avoid. Various pattern projection methods have been proposed in the past.

  For example, in the technique disclosed in Patent Document 1 (Japanese Patent Laid-Open No. 2000-65542), a projector that projects a coded pattern, a first camera that captures a projection pattern from the optical axis direction of the projector, and a projector And a second camera for photographing a projection pattern from a direction different from the optical axis direction of the first, and a new code is assigned and assigned to an area where the amount of change in the photographing pattern by the first camera relative to the projection pattern is a predetermined value or more. The first distance information is generated from the photographing pattern by the second camera using the code, and the three-dimensional image is obtained based on the first distance information and the luminance information obtained from the first camera. A photographing apparatus is configured. As an example, a stripe pattern having three levels of intensity is used as the projection pattern. By re-encoding the projection pattern using the pattern photographed by the first camera placed on the same optical axis, three-dimensional measurement can be performed with high accuracy.

Patent Document 2 (Japanese Patent Laid-Open No. 2002-131031) prepares a plurality of mask patterns that determine the exposure amount of stripe light, and sequentially encodes the mask patterns during one frame exposure time of the camera to encode a plurality of gradations. A pattern is projected.
JP 2000-65542 A JP 2002-131031 A

  However, when projecting a multi-level pattern as described above, the three-level pattern in the former example is a set of 6 stripes, and the latter example is a set of 16 stripes with 4 masks. A repeated pattern will be projected. Thus, when the repetition period is small, there is a problem that the probability of erroneous matching during code search processing increases. In order to avoid this problem, in the former example, the number of levels may be increased, and in the latter example, the types of masks are increased within one frame of the camera.

  However, when the number of pattern levels is increased in this way, adjacent pattern areas influence each other due to signal degradation factors such as the MTF of the projection system and the imaging system and the S / N of the CCD camera, and erroneous values are detected. A new problem arises that is more likely. Also, when measuring an object with a dark surface color, the reflectance will be small, so the dynamic range of the pattern will be small on the image captured by the camera, the gradation level difference for each stripe will be reduced, and the wrong value will be displayed in the code processing. There are also problems such as calculating.

  Furthermore, the shape data points acquired in these shape measurement methods are limited to the locations marked by the projected pattern, and are actually only points corresponding to the edge positions between stripes. On the other hand, there is a demand to increase the density of the points capable of measuring the shape, and the pattern must be made finer. In order to ensure the repetition cycle while making the pattern fine, it is necessary to increase the number of gradation levels, which causes another error problem related to the above-mentioned error problem of gradation step reduction for each stripe. There is a problem that these requirements are in a trade-off relationship and cannot be satisfied at the same time.

  The present invention has been made in view of such a problem, and an object of the present invention is to enable accurate and dense pattern detection in a three-dimensional shape measurement technique using a plurality of levels of projection patterns.

  In order to solve the above problems, a stripe pattern encoded with a predetermined luminance range, for example, a plurality of levels of luminance (which may be hues; the same applies hereinafter) divided at equal intervals from all white to all black is applied to the subject. In a three-dimensional shape measuring apparatus that obtains a three-dimensional image of a subject using a projector that projects and a camera that is arranged so as to deviate from the optical axis of the projector and that captures the subject, a difference in luminance level between two adjacent stripes A plurality of different stripe patterns having N or more (N is a positive number greater than 1, eg, N = 2) level or more are used. For example, the plurality of stripe patterns can be configured by taking out stripes in order from the basic stripe pattern composed of the stripes of the plurality of levels. However, the present invention is not limited to this. For example, when two stripe patterns are used, one stripe pattern is formed from the odd-numbered stripes of the basic stripe pattern, and the other stripe pattern is formed from the even-numbered stripes. Each of the plurality of stripe patterns obtained by sequentially removing the stripes from the basic stripe pattern and dividing the stripes prevents the arrangement (permutation) of two adjacent stripes from becoming the same during the repetition cycle. Further, when dividing a plurality of stripe patterns from the basic stripe pattern as described above, the level difference between adjacent stripes of the stripe pattern after division is N (N is a positive number greater than 1) or more. Select the underlying stripe pattern.

  A code corresponding to a plurality of stripe patterns is obtained after acquiring a coded edge image group by performing edge extraction and code addition processing corresponding to an edge between stripes on a captured image corresponding to each of the plurality of stripe patterns. The distance calculation process is performed after superimposing the grouped edge image group. Since the projection and imaging of the stripe pattern are performed for each stripe pattern, the distance calculation process is performed once. A distance calculation process may be performed for each coded edge image corresponding to each stripe pattern to integrate the calculation results.

  In this three-dimensional shape measuring apparatus, a group of stripe patterns projected onto a subject having a uniform color distribution divides all white to all black at equal intervals on a photographed image of the subject having a uniform color distribution by the camera. It is preferable that the input data is in consideration of the gamma characteristics of the projector and the camera so that the luminance is at a plurality of levels.

  Further, the present invention will be described.

  According to the present invention, a projector that projects a stripe pattern encoded with a plurality of levels of brightness set in advance within a predetermined luminance range onto a subject, and a camera that is arranged offset from the optical axis of the projector and shoots the subject A three-dimensional shape measuring apparatus for obtaining a three-dimensional image of the subject, comprising a calculating unit that calculates the distance to the subject by associating the stripe pattern with the projection image of the camera. A stripe pattern in which stripes are arranged so that the brightness level difference between the stripes is N (a positive number of 2 or more) level or more, and the edge positions between the stripes are shifted from each other, and the adjacent 2 included in the pattern period. Prepare multiple stripe patterns with different brightness levels (permutations) that do not overlap each other. The subject separately projected by photographing the subject, so that integration process after separately coded edge images obtained in each of the stripe pattern.

  In this configuration, by adopting a plurality of different stripe patterns and omitting the edge positions, the edge density is increased, and the level difference between adjacent stripes can be easily set to 2 or more. Therefore, accurate and dense pattern detection is possible.

  In this configuration, it is preferable that the plurality of luminance levels are set in consideration of gradation reproduction characteristics of the projector and the camera.

  The predetermined luminance range is, for example, a range from all white to all black.

  The plurality of luminance levels are preferably arranged at substantially equal intervals in the predetermined luminance range.

  A second camera having substantially the same optical axis as the projector is arranged, and the brightness level distribution in the stripe of the stripe pattern is readjusted according to the brightness distribution of the camera image of the second camera. preferable. The second camera may be arranged such that the optical axis is the same as that of the projector using a boom splitter, or the projector and the second camera are arranged relatively slightly shifted from each other. Alternatively, both optical axes may be the same.

  The above and other aspects of the invention are set forth in the appended claims and are described in detail below using examples.

  According to the present invention, it is possible to reduce the probability of a code search error and realize a high distance measurement point cloud density by using a plurality of stripe patterns with a large luminance level difference and shifted edge positions. it can.

  Embodiments of the three-dimensional shape measuring apparatus according to the present invention will be described below.

  FIG. 1 is a block diagram of a three-dimensional image measuring apparatus according to an embodiment of the present invention. In FIG. 1, the three-dimensional image measuring apparatus projects a pattern for three-dimensional measurement (for example, a liquid crystal projector) 10. , An imaging device (for example, a CCD camera, also called a first camera) 20, a triangulation imaging device (for example, a CCD camera, also called a second camera) 30, a calculation processing device 60 (a distance calculation unit) For example, a personal computer or a dedicated processing device). Reference numeral 40 denotes a half mirror, and reference numeral 50 denotes an object. The basic configuration of this three-dimensional measuring apparatus is the same as the configuration disclosed in Patent Document 1 (Japanese Patent Laid-Open No. 2000-65542). The pattern projection apparatus 10 uses a liquid crystal projector, a DLP (trademark) projector, or a slide projector. The pattern projection apparatus 10 employs a plurality of stripe patterns, sequentially projects the stripe patterns, and images are taken by the imaging devices 20 and 30. In this embodiment, two stripe patterns are used as will be described later (see the specific examples of stripe patterns in FIGS. 19 and 20), but the present invention is not limited to this, and three or more stripe patterns may be used. The projection pattern input to the pattern projection apparatus 10, for example, a liquid crystal projector, typically uses a stripe pattern with shading as shown in FIG. 2, for example, an object (object) shown on the right side of FIG. Project a pattern. Actually, the two stripe patterns shown in FIGS. 19 and 20 are individually projected. When a slide projector is used, projection patterns (two types) are formed on a slide film, or a metal film or the like is deposited on a glass pattern, and the transmittance is controlled by the film thickness, the retinal point pattern, or the like.

  FIG. 3 schematically shows a luminance profile in the horizontal direction of pattern data input to a liquid crystal projector, for example. In FIG. 3, for convenience of explanation, the projection pattern (pattern data) is a combination of seven types of luminance stripes in which 256 gradations are divided into six stages, but the present invention is not limited to this. In a specific stripe pattern to be described later, 14 types of luminance stripes are combined (see FIGS. 19 and 20). In the stripe pattern of FIG. 3, the adjacent stripes are arranged so as not to have a one-level level difference. This is equivalent to dividing 256 gradations into three levels (four levels of 0, 85, 170, and 255) as far as the level difference between adjacent stripes is concerned. In the case of repeating a normal four-level stripe into one set, the limit is to set one set to 12 stripes so that each combination of adjacent stripes does not appear in one set. Repeatedly, a stripe pattern including a large number of stripes is formed. If the same combination of adjacent stripes overlaps in the vicinity, it causes a code search error. On the other hand, when 7 levels of stripes are used and the adjacent stripes are arranged so as not to have a one-level level difference as in this embodiment, the same combination of adjacent stripes appears in one set. In order to avoid this, the number of stripes in one set can be about 28. In the range of at least 28 stripes, combinations of the same adjacent stripes do not overlap, and the probability of code search errors also decreases.

  FIG. 4 shows a pattern projection pattern. Pattern projection is performed every two stripe patterns. An imaging device (first camera 20) and a projection device (pattern projection device 10) are arranged on the same optical axis by a half mirror 40 or the like, an imaging device is prepared for triangulation measurement, and a stripe pattern as shown in FIG. 2 is projected. To do. Re-encoding is performed from an image (first camera image) observed by the image sensor (first camera 20) of the same optical axis, and an image (second image) observed by the measurement image sensor (second camera 30). A three-dimensional distance image (distance) is calculated using the camera image.

  FIG. 5 shows a configuration example for calculating the distance image. In this figure, portions corresponding to those in FIG. Components other than the pattern projection device 10, the first camera 20, and the second camera 30 are realized by the previous calculation processing device 60, for example. In FIG. 5, the pattern projection apparatus 10 projects two coded stripe patterns onto the object 50. These two stripe patterns are stored in the frame memory 110. The pattern switching unit 190 switches the stripe pattern. A projection pattern on the object 50 is imaged by the first camera 20 for monitoring and the second camera 30 for triangulation, and stored in the pattern image memories 120 and 150, respectively.

  The area dividing unit 130 divides the pattern image stored in the pattern image memory 120 into an area where the projection pattern (light) from the pattern projection apparatus 10 has sufficiently arrived (also referred to as area 2) and an area where it has not reached (also referred to as area 1). To divide. For example, for an area where the intensity difference between adjacent stripes is less than or equal to the threshold, it is determined that the projection pattern has not reached sufficiently, and the projection pattern has sufficiently reached an area where the intensity difference between stripes is greater than or equal to the threshold. Determined as an area. As described below, an edge pixel serving as a boundary line is calculated and a distance calculation is performed on an area where the projection pattern has sufficiently reached. For areas where the projection pattern does not reach sufficiently, distance calculation based on parallax is performed separately. Although not specifically described here, refer to Patent Document 1 for details.

  The recoding unit 160 extracts stripes for the extracted region 2, divides each stripe in the vertical direction for each stripe width, generates a square cell, and recodes the cell. This will be described in detail later.

  The code decoding unit 170 determines the code of each cell (edge) of the pattern image from the second camera 30 for triangulation stored in the pattern image memory 150 using the code from the recoding unit 160. . Thereby, the x coordinate of the pixel at the measurement point p (edge) in the pattern image of the pattern image memory 150 and the irradiation direction (slit angle) θ from the light source are determined, and the distance Z is measured by the equation (1) described later. (See FIG. 14). The three-dimensional image memory 180 stores the distance and the luminance value of the object acquired from the first camera 20 (stored in the luminance value memory 140) as three-dimensional image data.

  In this embodiment, two stripe patterns are projected in succession, and a projected image of each stripe pattern is captured to obtain two captured images. Edge extraction processing and code addition processing are performed on each captured image to obtain two sets of coded edge images. The obtained two sets of coded edge images are superimposed to obtain one integrated coded edge image having a high edge density and a good code distribution. Compared to the case where distance calculation is performed for each of multiple coded edge images by performing distance measurement calculation on the obtained integrated coded edge image, an error caused by the algorithm at the time of distance calculation Can be further reduced. A separate memory may be prepared for each coded edge image, or processing may be performed with one memory. Note that distance calculation may be performed separately from each coded edge image, and distance information obtained for each stripe pattern may be integrated to obtain comprehensive distance information.

  In this example, since two coded edge images can be created, for example, two pattern image memories 120 are prepared, and the respective images are integrated, and then the integrated coded edge image is stored in one or another prepared memory. Alternatively, one pattern image memory 120 may be used for each stripe pattern projection, and a coded edge image integrated therein may be held. The same applies to the pattern image memory 150.

  Details of the calculation of the three-dimensional shape in this configuration example will be further described.

  Re-encoding is performed according to the flowchart shown in FIG. 7 using the pattern image photographed by the first camera 20 for monitoring on the same optical axis and the pattern image used for light projection. First, the region of the pattern image photographed by the first camera 20 is divided. A region where the intensity difference between adjacent stripes is less than or equal to the threshold is extracted as region 1 where the projection pattern from the pattern projection apparatus 10 has not reached, and a region where the intensity difference between stripes is greater than or equal to the threshold is extracted as region 2. (S10), the edge pixel that becomes the boundary line for the region 2 is calculated.

  Stripes are extracted from the extracted region 2, and each stripe is divided in the vertical direction for each stripe width to generate a square cell. The average value of the intensity is taken for each generated cell, and the average value is set as the intensity of each cell (S11). Compare the intensities between the corresponding cells in order from the center of the image, and if the inter-cell intensity differs by more than a threshold because the pattern has changed due to factors such as the reflectance of the object, the distance to the object, etc. Code generation and allocation are performed (S12 to S16).

  FIG. 8 is a simplified example for simplicity, but the left side of FIG. 8 is a light projection pattern coded by the arrangement of stripes. The intensity is 3 (strong), 2 (medium), 1 (weak) is assigned. The right side of FIG. 8 is obtained by extracting the stripes photographed by the first coaxial camera 20 in the direction perpendicular to the stripes by the cell width. In the example on the upper right in FIG. 8, since the strength changes in the third cell from the left and a new code appears, a new code of 0 is assigned. In the lower right example of FIG. 8, since the existing code appears in the third cell from the left and the second cell from the top, as a new code (232, 131) from the cell sequence (vertical) The code is expressed by (line, horizontal line). This re-encoding is equivalent to projecting a complex pattern such as a two-dimensional pattern at a site where the shape of the object is rich in change, and projecting a simple pattern at a site where there is little change. This process is repeated and recoding is performed by assigning unique codes to all cells.

  As an example, FIGS. 11 and 12 show simplified images obtained by the first camera 20 and the second camera 30 when the pattern of FIG. 10 is projected onto the object of FIG. In this example, FIG. 13 is obtained as a new coded pattern on the surface of the plate.

  Next, stripes are extracted from the stripe image obtained by the second camera 30 and divided into cells as before. For each cell, the code of each cell is detected using the recoded code, and the irradiation direction θ from the light source is calculated based on the detected code. The distance Z is calculated by Equation (1) using θ of the cell to which each pixel belongs, the x coordinate on the image taken by the camera 2, the focal length F and the base line length L which are camera parameters. FIG. 14 shows the relationship among the measurement point p, the irradiation direction θ from the light source, the x coordinate on the image captured by the second camera 30, the focal length F that is a camera parameter, and the baseline length L. .

  Z = FL / (x + Ftanθ) ---- Equation (1)

  This calculation is actually performed using the x-coordinate of the cell boundary. At this time, the x-coordinate is calculated in a unit smaller than the pixel resolution of the camera, thereby improving the measurement accuracy. The x-coordinate value is obtained from the brightness average values d1 and d2 of appropriate pixels of the cells on both sides of the edge pixel calculated in advance and the brightness de of the edge pixel. A pixel position de ′ (indicated by x in the drawing for convenience) corresponding to the luminance de is obtained from a straight line obtained by linear interpolation from the pixel positions p1 and p2 adjacent to the edge pixel and the luminance average values d1 and d2, and this is the x coordinate value. . (See Figure 15)

  In the example schematically shown in FIG. 3, the projection pattern is a combination of luminance stripes for each of the 42 gradations or 43 gradations in which 256 gradations are divided into 6 gradations. Therefore, the intensity difference between the stripes is large and the x-coordinate value can be easily calculated as compared with the pattern in which the luminance stripes are simply divided into six levels. FIG. 16 shows the luminance distribution of the pixel unit of the camera when the intensity difference between stripes is large and small. The average luminance value of several pixels on both sides of the edge pixel can take a range indicated by the thickness of the gray horizontal line due to the influence of noise of each pixel. As shown on the left in FIG. 16, when the intensity difference is large, the influence of noise on the luminance average value of several pixels on both sides of the edge pixel is expressed by the thickness of each gray line when the calculation method of FIG. 15 is applied. As a result, the x coordinate value is determined within the range of a. However, when the intensity difference is small, the ratio of the noise component of the luminance average value of several pixels on both sides of the edge pixel becomes relatively large with respect to the intensity difference, which causes ambiguity in the calculation of the x coordinate value. The range becomes the range of b, and as a result, the measurement accuracy is lowered. For this reason, it is desirable that the difference in intensity between stripes is large.

  FIG. 6 shows a configuration example for obtaining the x coordinate. In FIG. 6, the edge right neighboring pixel position input unit 210, the edge right cell luminance average value input unit 220, the edge left neighboring pixel position input unit 230, the edge left cell luminance average value input unit 240, and the edge luminance input unit 250 respectively. d1, p1, d2, p2, and de are supplied to the interpolation calculation unit 200 to calculate the x coordinate as described above.

  In this embodiment, since the pattern is constrained so that the intensity difference between stripes is 2 levels or more, the x-coordinate value can be measured with high accuracy.

  Next, correction of gamma characteristics of the projector and camera will be described.

  When a liquid crystal projector is used as the pattern projection device (projector) 10, an output image projected on an input image of the liquid crystal projector generally has a gamma characteristic. Therefore, even if 256 gradations are divided into six equal parts in the input image, the brightness of the projected pattern is not equal to seven levels. Therefore, the gamma characteristic must be taken into account when creating the input image. In the projector having the gamma characteristic of the output level on the vertical axis with respect to the input level on the horizontal axis as shown in FIG. 17, the input image shows each luminance gradation value of 0, 148, 185, 203, 222, 237, and 255 from the graph. It is desirable to have a stripe pattern. The same applies to the case where the pattern projector (projector) 10 is a DLP projector. When the pattern projector (projector) 10 is a slide projector, it is necessary to prepare data in consideration of the gamma characteristics of the slide film at the time of film creation.

  Similarly, a gamma characteristic also exists in a CCD camera. Therefore, when it is desired to obtain a stripe pattern having a uniform luminance interval on a camera image, an input image that further considers the gamma characteristic of the CCD camera is required.

  Next, specific examples of the two stripe patterns of this embodiment will be described.

  Here, first, in order to increase the density of the distance measurement points, consider a case where the stripe pattern to be used corresponds to a large number of gradation levels and a narrow stripe width shown in FIG. In this case, as described above, an error due to too many gradation divisions is likely to occur. In addition, since the stripe width is narrow, the gray level detection error increases, and a desired result cannot be obtained. Accordingly, the stripe pattern shown in FIG. 18 is divided as shown in FIGS. 19 and 20 to create a plurality (two in this case) of stripe patterns and used in this embodiment (for convenience, the divided stripe pattern and Sometimes called). In this embodiment, a divided stripe pattern is projected continuously, and imaging is performed corresponding to each divided stripe pattern to obtain a plurality of captured images. Edge extraction processing and code addition processing are performed on each captured image to obtain a plurality of coded edge images. A plurality of obtained coded edge images are superimposed to obtain one integrated coded edge image having a high edge density and a good code distribution. Compared to the case where distance calculation is performed for each of multiple coded edge images by performing distance measurement calculation on the obtained integrated coded edge image, an error caused by the algorithm at the time of distance calculation Can be further reduced.

  Here, although the description has been made using the divided stripe pattern in comparison with the stripe pattern of FIG. 18, the basic stripe pattern of FIG. 18 is not essential in this embodiment. In short, a plurality of, for example, two stripe patterns are used. It suffices that the edge is shifted and any of the types of adjacent stripes arranged in one stripe pattern (permutation of two stripes) is not included in the other stripe pattern. That is, it is only necessary to increase the measurement density (edge density) and make it possible to distinguish edges between a plurality of stripe patterns.

  In addition, this invention is not limited to the above-mentioned Example, A various change is possible in the range which does not deviate from the meaning. For example, in the above embodiment, an example of equally dividing into 7 levels or 14 levels has been described, but it goes without saying that other numbers of levels may be set. In addition, when 256 gradations are equally divided into 7 levels or 14 levels, 255 cannot be divided by 6 or 13, so rounding the interval between each level to 42 gradations, 43 gradations, 19 gradations or 20 gradations is a problem. It is included in the technical scope of the invention.

  Further, it goes without saying that the present invention is effective for projection light having invisible wavelengths such as near infrared in addition to visible wavelengths. Instead of the luminance pattern, a hue pattern may be used.

  For example, in the above-described embodiment, the projection device 10 and the monitor imaging device 20 are arranged on the same optical axis (same principal point) using the half mirror 20, but as shown in FIG. The projection device 10 and the imaging device 0 may be arranged so as to be negligibly spaced in the direction of the stripe (edge) of the pattern, and may be arranged on substantially the same optical axis (same principal point). In this case, it is possible to avoid power reduction and variation due to pattern light loss and distribution by the half mirror.

It is a figure which shows the apparatus structure of the Example of this invention. It is a figure which shows an example of the pattern and subject for demonstrating the said Example. It is a figure which shows the example of a stripe pattern of the above-mentioned Example. It is a schematic diagram explaining operation | movement of the said Example. It is a block diagram explaining the structural example of the said Example. It is a figure explaining the circuit structural example which performs the interpolation calculation of the coordinate x on the image of the 2nd camera of the measurement point of the said structural example. It is a flowchart explaining operation | movement of the said Example. It is a figure explaining coding of the above-mentioned example. It is an arrangement diagram of a camera and a subject for explaining the coding of the embodiment. It is a pattern diagram for demonstrating the encoding of the said Example. It is a figure which shows the example of the monitor image of the 1st camera of the above-mentioned Example. It is a figure which shows the example of the monitor image of the 2nd camera 2 of the above-mentioned Example. It is a figure explaining the part to which the brightness | luminance changed in the to-be-photographed object in the above-mentioned Example. It is a figure explaining distance calculation in the above-mentioned example. It is calculation explanatory drawing of the edge coordinate of the above-mentioned Example. It is a figure explaining the difference of the edge coordinate calculation by the gradation difference in the said Example. It is a gamma characteristic and pattern input value calculation explanatory drawing of the light projector (projector) of the said Example. It is a figure explaining the example of the stripe pattern used as the origin of a division | segmentation stripe pattern. It is a figure explaining one example of a division | segmentation stripe pattern. It is a figure explaining the other example of a division | segmentation stripe pattern. It is a figure explaining the modification of the above-mentioned Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Pattern projection apparatus 20 1st camera 30 for a monitor 2nd camera 40 for a triangulation 50 Half mirror 50 Object 110 Frame memory 120 Pattern image memory 130 Area division part 140 Luminance value memory 150 Pattern image memory 160 Recoding part 170 Code decoding unit 180 3D image memory 190 Pattern switching unit 200 Interpolation calculation unit 210 Edge right neighboring pixel position input unit 220 Edge right cell luminance average value input unit 230 Edge left neighboring pixel position input unit 240 Edge left cell luminance average value input unit 250 Edge luminance input section

Claims (8)

  A projector that projects a stripe pattern encoded with a plurality of levels of brightness set in advance within a predetermined luminance range onto a subject, a camera that is arranged offset from the optical axis of the projector and that captures the subject, and the stripe pattern In a three-dimensional shape measuring apparatus that includes a calculation unit that calculates a distance to the subject by associating with a photographed image of the camera and obtains a three-dimensional image of the subject, a difference in luminance level between two adjacent stripes A stripe pattern in which stripes are arranged so as to be N (N is a positive number of 2 or more) level, and the edge positions between the stripes are shifted from each other, and the brightness of two adjacent stripes included in the pattern period Prepare multiple types of levels that do not overlap each other, and each stripe pattern for each subject Projected by photographing the subject, three-dimensional shape measuring apparatus, characterized in that the integration process after separately coded edge images obtained in each of the stripe pattern.   The three-dimensional shape measuring apparatus according to claim 1, wherein the plurality of luminance levels are set in consideration of gradation reproduction characteristics of the projector and the camera.   The three-dimensional shape measuring apparatus according to claim 1 or 2, wherein the predetermined luminance range is a range from all white to all black.   The three-dimensional shape measuring apparatus according to claim 1, 2, or 3, wherein the plurality of luminance levels are arranged at substantially equal intervals in the predetermined luminance range.   An auxiliary camera having substantially the same optical axis as that of the projector is disposed, and the distribution of the luminance level in the stripe of the stripe pattern is readjusted according to the luminance distribution of the camera image of the auxiliary camera. The three-dimensional shape measuring apparatus according to 3 or 4.   By projecting a stripe pattern encoded with a plurality of levels of luminance set in advance in a predetermined luminance range onto a subject by a projector, and photographing the subject with a camera arranged offset from the optical axis of the projector, In a three-dimensional shape measuring method for obtaining a three-dimensional image of a subject, a stripe pattern in which stripes are arranged so that the luminance level difference between two adjacent stripes is 2 levels or more, and the edge positions between the stripes are shifted from each other. A plurality of adjacent stripes whose brightness levels are arranged in the pattern period so that they do not overlap each other, and project each stripe pattern onto the subject separately. After capturing and coding separately the edge images acquired in each of the stripe patterns 3-dimensional shape measuring method characterized by treating.   A projector that projects a stripe pattern encoded with a plurality of levels of brightness set in advance within a predetermined luminance range onto a subject, a camera that is arranged offset from the optical axis of the projector and that captures the subject, and the stripe pattern A three-dimensional shape measuring apparatus that includes a calculation unit that calculates a distance to the subject by associating with a photographed image of the camera and obtains a three-dimensional image of the subject, with a different repetitive phase from a basic stripe pattern By taking out stripes every N (N is a positive number of 2 or more), the base stripe pattern is divided to prepare a plurality of stripe patterns, and each of the plurality of stripe patterns is projected onto the subject separately. Photograph the subject and separate the edge images obtained with each of the stripe patterns 3-dimensional shape measuring apparatus, characterized in that the integration process after the encoding.   By projecting a stripe pattern encoded with a plurality of levels of luminance set in advance in a predetermined luminance range onto a subject by a projector, and photographing the subject with a camera arranged offset from the optical axis of the projector, In a three-dimensional shape measurement method for obtaining a three-dimensional image of a subject, the basic stripe pattern is divided by taking out stripes every N (N is a positive number of 2 or more) at different repetition phases from the basic stripe pattern. Preparing a plurality of stripe patterns, projecting each of the plurality of stripe patterns separately onto the subject, photographing the subject, and integrating the edge images obtained with each of the stripe patterns after separately coding A three-dimensional shape measuring method characterized by processing.