JP2020086578A - Imaging device - Google Patents

Abstract

To provide an imaging device capable of automatically executing complicated setting for calibration for chromatic aberration of magnification.SOLUTION: An imaging device is provided that includes: an imaging unit which acquires an image of a marker through a lens and captures an image of the marker by means of two or more line sensors having color filters of different colors for the respective colors; a calculation unit for calculating one or more displacement amounts of imaging pixels between the line sensors subjected to spectral dispersion of wavelengths of the marker by the lens; and a calibrating unit for executing calibration, on the basis of the calculated displacement amount of the imaging pixels, such that the imaging pixels captured by the respective line sensors of the two or more line sensors coincide with each other.SELECTED DRAWING: Figure 1

Description

The present invention relates to an image pickup device, and more particularly to a technique of an image pickup device that corrects chromatic aberration.

In recent years, various imaging apparatuses that acquire an image and correct the acquired image have been studied. Since the lens of the image pickup device has a different refractive index depending on the wavelength, an image shift occurs between light having a long wavelength and light having a short wavelength depending on the image forming position.

For example, in a color image composed of three primary colors of red (red), green (green), and blue (blue), blurring occurs due to image shift. Specifically, red has a longer wavelength than green, and blue has a shorter wavelength than green. Therefore, the images of red and blue are displaced in different directions. This causes yellow or cyan bleeding at the boundary between black and white.

Therefore, an image processing apparatus has been proposed that corrects chromatic aberration of magnification due to different refractive indices of light wavelengths (see Patent Document 1).

Japanese Patent No. 4492392

When calibrating the chromatic difference of magnification, the image processing apparatus uses a plurality of parameters, and therefore only an engineer having specialized knowledge can set the calibration. Further, since the setting of the calibration is complicated and it is necessary to set it manually, the setting is troublesome and the burden on the engineer is large.

Then, this invention is made|formed in view of such a subject, and makes it a main object to provide the imaging device which can perform the complicated setting in the calibration of a magnification chromatic aberration automatically.

As a result of earnest research to solve the above-mentioned object, the present inventor succeeded in automatically executing complicated setting in calibration of lateral chromatic aberration, and completed the present invention.

That is, according to the present invention, an image capturing unit that captures an image of a marker through a lens and captures the marker by two or more line sensors that have color filters of different colors for each color, and the wavelength of the marker by the lens. Is calculated, and a calculation unit that calculates the shift amount of the image pickup pixel between the one or more line sensors that are split, and each of the two or more line sensors based on the calculated shift amount of the image pickup pixel An imaging device, comprising: a calibration unit that performs calibration so that the imaging pixels imaged by the line sensor match each other.

According to the present invention, it is possible to automatically perform a complicated setting in the calibration of the chromatic aberration of magnification. The effects of the present invention are not necessarily limited to the above effects, and may be any of the effects described in the present invention.

It is a block diagram of an imaging device of a 1st embodiment concerning the present invention. It is explanatory drawing which shows the magnification chromatic aberration by the refractive index of a lens. It is explanatory drawing which showed the example of the marker which an imaging device images. It is explanatory drawing which shows the imaging pixel of the marker of the calibration area imaged with the line sensor. The calculation unit calculates the amount of shift between the image pickup pixels of the line sensor R and the line sensor G, and the calibration unit performs calibration so that the image pickup pixel imaged by the line sensor R matches the image pickup pixel imaged by the line sensor G. It is explanatory drawing which showed the method to perform. The calculation unit calculates the amount of deviation between the image pickup pixels of the line sensor B and the line sensor G, and the calibration unit performs calibration so that the image pickup pixels captured by the line sensor B match the image pickup pixels captured by the line sensor G. It is explanatory drawing which showed the method to perform. It is explanatory drawing which shows embodiment which images a belt conveyor which is a to-be-photographed object, and carries out a calibration, when a marker is detected in a calibration area|region by the imaging device of the 3rd Embodiment which concerns on this invention.

Preferred modes for carrying out the present invention will be described below with reference to the drawings. The embodiments described below are examples of typical embodiments of the present invention, and the scope of the present invention should not be construed narrowly.

<1. First Embodiment (Example 1 of Imaging Device)>
FIG. 1 shows a block diagram of an image pickup apparatus 100 according to the first embodiment of the present invention. FIG. 1 is a block diagram of an image pickup apparatus 100 according to the first embodiment of the present invention.

[Constitution]
The image pickup apparatus 100 according to the first embodiment includes an image pickup unit 10, a processing circuit 20, a storage circuit 30, an input circuit 40, a display 50, an image storage circuit 60, and an internal bus 70.

The imaging unit 10 includes a lens 1, a line sensor R, a line sensor G, and a line sensor B. The imaging unit 10 acquires an image via the lens 1. For example, the imaging unit 10 acquires an image of a marker described later via the lens 1 and has two or more line sensors (line sensor R, line sensor G, and line sensor B) that have color filters of different colors for each color. The marker is imaged by.

The line sensor R has a red (R) color filter. The line sensor G has a green (G) color filter. The line sensor B has a blue (B) color filter. The line sensors (line sensor R, line sensor G, and line sensor B) each perform photoelectric conversion. Each of the line sensors (line sensor R, line sensor G, and line sensor B) one-dimensionally reads the amount of light that has passed through the filter of each color, converts it into an electrical signal, and outputs it.

The processing circuit 20 is a processor that realizes a function corresponding to the program by reading the program from the memory (memory circuit 30) and executing the program. Specifically, the processing circuit 20 (processor) realizes the functions of the calculation unit 21 and the calibration unit 22 by executing the read program.

The calculator 21 disperses the wavelengths of the markers by the lens 1, and calculates the shift amount of the imaging pixel between the dissociated one or more line sensors (line sensor R, line sensor G, and line sensor B). For example, when the predetermined G channel imaged by the line sensor G is used as a reference, the calculation unit 21 calculates the deviation amount between the image pickup pixels of the predetermined R channel imaged by the line sensor R and the predetermined G channel, and the line. The shift amount between the image pickup pixels of the predetermined B channel and the predetermined G channel imaged by the sensor B is calculated.

The calibrating unit 22 includes line sensors (line sensor R, line sensor R) of each of the three line sensors (line sensor R, line sensor G, and line sensor B) based on the shift amount of the imaging pixel calculated by the calculating unit 21. The calibration is performed so that the image pickup pixels imaged by G and the line sensor B) match. Note that calibration means calibration. That is, for example, the calibration unit 22 sets the deviation amount of the predetermined R channel imaged pixel and the predetermined B channel imaged pixel calculated by the calculation unit 21 so as to match the predetermined G channel imaged pixel. Calibrate.

Here, the chromatic aberration of magnification in which the image pickup pixel shifts due to the refractive index of the lens will be described. FIG. 2 is an explanatory diagram showing lateral chromatic aberration due to the refractive index of the lens 1.

As shown in FIG. 2, the lens 1 transmits light to form an image on the imaging surface IS. Here, the refractive index of light differs depending on the wavelength. Therefore, the light obliquely incident on the optical axis AX forms images at different positions on the imaging surface IS. Therefore, color shift occurs around the image distant from the optical axis AX.

Specifically, the red wavelength light RL forms a red image height HR on the imaging surface IS via the lens 1. Further, the light GL of the green wavelength forms the green image height HG on the imaging surface IS via the lens 1. Further, the light BL having a blue wavelength forms a blue image height HB on the imaging surface IS via the lens 1.

As described above, due to the difference in the refractive index of the light, the light of each wavelength (light RL, light GL, and light BL) is imaged at different positions, the color of the image is shifted, and the image is shifted. May be bleeding. Such image color shift and image color bleeding is generally called lateral chromatic aberration.

In the imaging device 100 according to the first embodiment of the present invention, the calculation unit 21 of the processing circuit 20 calculates the shift amount of the imaging pixel due to the lateral chromatic aberration, and the calibration unit 22 of the processing circuit 20 calculates the calculated imaging pixel. Based on the shift amount, the calibration is performed so that the imaged imaged pixels match.

The word "processor" that constitutes the processing circuit 20 is, for example, a dedicated or general-purpose CPU (Central Processing Unit), an application-specific integrated circuit (ASIC), a programmable logic device (for example, simple programmable). A circuit such as a logic device (Simple Programmable Logic Device: SPLD), a complex programmable logic device (CPLD), and a field programmable gate array (FPGA) is meant.

The processor realizes each function by reading and executing a program stored in the memory or directly incorporated in the circuit of the processor. When a plurality of processors are provided, the memory for storing the program may be provided individually for each processor, or the memory circuit 30 of FIG. 1 stores the program corresponding to the function of each processor. It doesn't matter.

The storage circuit 30 is configured by a storage device including a ROM (Read Only Memory), a RAM (Random Access Memory), an HDD (Hard Disk Drive), and the like. The memory circuit 30 is used for storing IPL (Initial Program Loading), BIOS (Basic Input/Output System) and data, used as a work memory of the processing circuit 30, or temporarily storing data. Be done. The HDD is a storage device that stores programs (OS (Operating System) and the like other than application programs) installed in the imaging device 100 and data. It is also possible to provide the OS with a GUI (Graphical User Interface) that uses graphics frequently to display information on the display 50 to the operator and can perform basic operations by the input circuit 40.

The input circuit 40 is a circuit that inputs a signal from an input device such as an operation button, a keyboard, a pointing device (mouse, etc.) that can be operated by an operator, and here, the input device itself is also included in the input circuit 40. And In this case, an input signal according to the operation is sent from the input circuit 40 to the processing circuit 20.

The display 50 is a display device having a function of displaying a captured image captured by the image capturing unit 10. The display 50 includes an image synthesizing circuit (not shown), a VRAM (Video Random Access Memory), a screen, and the like.

The image storage circuit 60 is configured to correct a captured image captured by the image capturing unit 10 with correction data based on calibration and store the corrected image. The image storage circuit 70 is composed of a storage circuit including, for example, a RAM and an HDD.

The internal bus 70 is connected to each component so that the processing circuit 20 controls the imaging device 100 as a whole. The internal bus 70 is composed of, for example, a circuit for transmitting data and signals in the imaging device 100.

[motion]
Next, the automatic calibration process of the image capturing apparatus 100 according to the first embodiment will be described in detail with reference to FIGS. 3 to 6.

FIG. 3 is an explanatory diagram showing an example of a marker imaged by the imaging device 100. In FIG. 3A, an example in which markers (marker MA1, marker MA2, and marker MA3) are provided at substantially the left and right ends and the center of the calibration area CA1 for executing the calibration of the chart CH1. Shows. FIG. 3B shows an example in which the markers (marker MA1 and marker MA2) are provided at substantially the left and right ends of the calibration area CA2 for executing the calibration of the chart CH2. FIG. 3C shows an example in which the marker (marker MA4) is provided in a predetermined range of the calibration area CA3 for executing the calibration of the chart CH3. In addition, in the first embodiment, the markers (markers MA1 to MA4) are formed by white and black lines.

It should be noted that although the chart is provided with the marker in the present embodiment, the present invention is not limited to this. For example, the chart may be a test chart, contrast or energy. Furthermore, embossed unevenness is also applicable.

Hereinafter, a method of performing calibration will be described for each of the charts (chart CH1, chart CH2, and chart CH3) illustrated in FIG. Each marker (marker MA1 to marker MA4) has a white and black line of 2 to 10 pixels in the vertical direction. In addition, unless otherwise specified, “upper” means the upper direction in each drawing, and “right” means the right direction in each drawing. The example of FIG. 3C will be described in the second embodiment.

A chart CH1 is shown in FIG. The chart CH1 has a calibration area CA1 for executing calibration. In addition, the chart CH1 is provided with markers MA1, MA2, and MA3 at substantially the left and right ends and substantially the center of the calibration area CA1.

Here, the substantially end portion includes the end portion of the calibration area CA1 and means, for example, an area provided within 100 pixels from the left and right ends of the calibration area CA1. Further, the substantially center means, for example, a region including the center of the calibration region CA1 and within 10 pixels on the left and right of the center of the chart CH1.

When the chart CH1 is imaged, the image capturing unit 10 of the image capturing apparatus 100 acquires captured images of the marker MA1, the marker MA2, and the marker MA3 in the calibration area CA1. Here, FIG. 4 shows the imaging pixels acquired by the imaging device 100.

FIG. 4 is an explanatory diagram showing image pickup pixels of the marker MA1, the marker MA2, and the marker MA3 in the calibration area CA1 imaged by the three line sensors (line sensor R, line sensor G, and line sensor B). 4A shows the image pickup pixels imaged by the line sensor R, FIG. 4B shows the image pickup pixels imaged by the line sensor G, and FIG. 4C shows the line sensor B. The imaging pixel which imaged is shown.

Comparing the image pickup pixels, for example, as shown in FIG. 4A, the image pickup pixel imaged by the line sensor R is displaced outward from the image pickup pixel imaged by the line sensor G of FIG. 4B. There is. Further, for example, as shown in FIG. 4C, the image pickup pixel imaged by the line sensor B is displaced inward from the image pickup pixel imaged by the line sensor G of FIG. 4B. That is, FIG. 4 shows a pixel shift of lateral chromatic aberration.

Here, the calculation unit 21 of the processing circuit 20 according to the first embodiment of the present invention calculates the shift amount of the imaging pixel between one or more line sensors (line sensor R, line sensor G, and line sensor B). .. In addition, the calibration unit 22 of the processing circuit 20 according to the first embodiment of the present invention uses each of the three line sensors (the line sensor R, the line sensor G, and the line sensor B) based on the calculated image pickup pixel. Calibration is performed so that the image pickup pixels picked up by the line sensor match.

First, it is considered to perform calibration so that the image pickup pixel imaged by the line sensor R and the image pickup pixel imaged by the line sensor B match the image pickup pixel imaged by the line sensor G.

In FIG. 5, the calculation unit 21 calculates the shift amount of the imaging pixels between the line sensors (the line sensor R and the line sensor G), and the calibration unit 22 images the imaging pixels imaged by the line sensor R by the line sensor G. It is explanatory drawing which showed the method of performing a calibration so that it may match with the image picked-up pixel.

FIG. 5A shows a pixel shift between the image pickup pixel (solid line) imaged by the line sensor R and the image pickup pixel (dotted line) imaged by the line sensor G. The image pickup pixel indicated by the solid line is an image pickup pixel imaged by the line sensor R, and swells outside than the image pickup pixel imaged by the line sensor G indicated by the broken line. Here, the calculation unit 21 of the processing circuit 20 calculates the amount of deviation between the image pickup pixel of the line sensor R and the image pickup pixel of the line sensor G.

FIG. 5B shows the amount of deviation between the image pickup pixel imaged by the line sensor R and the image pickup pixel imaged by the line sensor G. The center of FIG. 5(B) is a position corresponding to the marker MA3 (see FIG. 3(A)), and shows the approximate center of the chart CH1. For example, the marker MA3 (see FIG. 3A) is “0” when there is no shift in the image pickup pixel as the alignment of the substantially center of the chart CH1. Note that, for example, even when the image pickup pixel is displaced at the position of the marker MA3, the calibration can be appropriately executed. Further, for example, even if the marker MA3 is not at the substantially central position, the position of the marker MA3 is Can be set as a substantially central position. It should be noted that the marker MA3 is not limited to the substantially center position, and even if the marker MA3 is actually deviated from the substantially center position, the position of the marker MA3 can be intentionally used as a positioning marker.

On the other hand, the left side of FIG. 5B is the position corresponding to the marker MA1 (see FIG. 3A), and the image pickup pixel imaged by the line sensor R is the image pickup pixel imaged by the line sensor G. On the other hand, it is shifted outward by "-0.8" pixels. Further, the right side of FIG. 5B is a position corresponding to MA2 (see FIG. 3A), and the image pickup pixel imaged by the line sensor R is “0” with respect to the image pickup pixel imaged by the line sensor G. .8” pixels are shifted outward. In FIGS. 5B and 5C, when the image sensor is shifted to the right with respect to the image sensor of the line sensor G, it is expressed as a positive value and is displaced to the left with respect to the image sensor of the line sensor G. In that case, it shall be expressed as a negative value.

Further, the calculation unit 21 of the processing circuit 20 can calculate, for example, the amount of deviation from the image pickup pixel of the marker MA3 to the image pickup pixel of the marker MA1 by interpolation. Similarly, the calculation unit 21 can calculate the shift amount from the image pickup pixel of the marker MA3 to the image pickup pixel of the marker MA2 by interpolation. In this case, for example, the calculation unit 21 moves toward the left side from the center of FIG. 5C, and at the predetermined position, “−0.2, −0.3, −0.4, −0.6, −. 0.8” and the shift amount of the image pickup pixel are calculated by interpolation. In addition, for example, the calculation unit 21 picks up “0.2, 0.3, 0.5, 0.6, 0.8” at a predetermined position as moving from the center of FIG. The pixel shift amount is calculated by interpolation.

In this way, the calculation unit 21 can calculate the shift amount of the image pickup pixel between the line sensor R and the line sensor G by interpolation at a predetermined position. As a result, the calibration unit 22 can perform calibration based on the calculated shift amount of the image pickup pixels so that the image pickup pixels imaged by the line sensors R and G match. it can.

Specifically, the calibration unit 22 shifts the image pickup pixel imaged by the line sensor R based on the shift amount of FIG. 5C, and thus the image is picked up by the line sensor G as shown in FIG. 5D. It is possible to match the image pickup pixel with the image pickup pixel. After performing the calibration in this way, the calibration unit 22 stores the shift amount of FIG. 5C as the correction data in the storage circuit 30 or the image storage circuit 60.

Next, it is considered to perform the calibration so that the image pickup pixel imaged by the line sensor B matches the image pickup pixel imaged by the line sensor G.

In FIG. 6, the calculation unit 21 calculates the shift amount of the image pickup pixels between the line sensors (the line sensor B and the line sensor G), and the calibration unit 22 takes the image pickup pixels of the line sensor B by the line sensor G. It is explanatory drawing which showed the method of performing a calibration so that it may match with the image picked-up pixel.

FIG. 6A shows a pixel shift between the image pickup pixel (solid line) imaged by the line sensor B and the image pickup pixel (dotted line) imaged by the line sensor G. The image pickup pixel indicated by the solid line is an image pickup pixel imaged by the line sensor B, and is recessed inside the image pickup pixel imaged by the line sensor G indicated by the broken line. Here, the calculation unit 21 of the processing circuit 20 calculates the amount of deviation between the image pickup pixel of the line sensor B and the image pickup pixel of the line sensor G.

FIG. 6B shows the amount of deviation between the image pickup pixel imaged by the line sensor B and the image pickup pixel imaged by the line sensor G. The center of FIG. 6B is a position corresponding to the marker MA3 (see FIG. 3A) and is “0”, which means that the center positions match. On the other hand, the left side of FIG. 6B is the position corresponding to the marker MA1 (see FIG. 3A), and the image pickup pixel imaged by the line sensor B is the image pickup pixel imaged by the line sensor G. On the other hand, it is shifted inward by "0.6" pixels. In addition, the right side of FIG. 6B is a position corresponding to the marker MA2 (see FIG. 3A), and the image pickup pixel imaged by the line sensor B is “ -0.6" pixel is shifted inward. Note that in FIGS. 6B and 6C, when the image sensor is shifted to the right with respect to the image sensor of the line sensor G, it is expressed as a positive value, and is displaced to the left with respect to the image sensor of the line sensor G. In that case, it shall be expressed as a negative value.

Further, the calculation unit 21 of the processing circuit 20 can calculate, for example, the amount of deviation from the image pickup pixel of the marker MA3 to the image pickup pixel of the marker MA1 by interpolation. Similarly, the calculation unit 21 can calculate the shift amount from the image pickup pixel of the marker MA3 to the image pickup pixel of the marker MA2 by interpolation. In this case, for example, as the calculation unit 21 proceeds to the left from the center of FIG. 6C, “0.2, 0.3, 0.4, 0.5, 0.6” is displayed at a predetermined position. The shift amount of the image pickup pixel is calculated by interpolation. Further, for example, as the calculation unit 21 proceeds from the center of FIG. 6C to the right side, “−0.2, −0.3, −0.4, −0.5, −0 at a predetermined position. .6” and the shift amount of the image pickup pixel are calculated by interpolation.

In this way, the calculation unit 21 can calculate the shift amount of the image pickup pixel between the line sensor B and the line sensor G by interpolation at a predetermined position. As a result, the calibration unit 22 can perform the calibration based on the calculated shift amount of the image pickup pixels so that the image pickup pixels imaged by the line sensors B and G match. it can.

Specifically, the calibrating unit 22 shifts the image pickup pixels picked up by the line sensor B based on the shift amount of FIG. 6C, so that the line sensor G picks up an image as shown in FIG. 6D. It is possible to match the image pickup pixel with the image pickup pixel. After performing the calibration in this way, the calibration unit 22 stores the deviation amount of FIG. 6C as the correction data in the storage circuit 30 or the image storage circuit 60.

In the first embodiment, as shown in FIG. 3A, the markers (marker MA1, marker MA2, and marker MA3) are provided at the left and right substantially end portions and substantially the center of the calibration area CA1. The embodiment is not limited to this. For example, as shown in FIG. 3B, the marker MA3 provided substantially at the center can be deleted so that the calibration is not executed. The marker MA3 indicates the approximate center of the chart 1, and when it is not necessary to perform the alignment of the center position of the chart 1, the execution of the calibration of the marker MA3 can be excluded. In particular, since the marker MA3 is generally less likely to be displaced at the substantially central position, it may be executed once. Therefore, once the calibration is performed at the center position, it is possible to exclude the execution of the calibration by assuming that the center positions are aligned thereafter, and reduce the time required for the calibration.

The shift amount shown in FIGS. 5C and 6C is calculated by the calculation unit 21 of the processing circuit 20 between the line sensors (line sensor R and line sensor G, line sensor B and line sensor G). Although the shift amount is calculated by interpolation, for example, when the shift amount has linearity, it can be calculated by applying spline interpolation.

As described above, the image pickup apparatus 100 according to the first embodiment of the present invention includes the image pickup unit 10 and the processing circuit 20, and the processing circuit 20 includes the calculation unit 21 and the calibration unit 22. .. The calculation unit 21 disperses the wavelengths of the markers by the lens 1, calculates the amount of deviation of the imaged pixels between the separated line sensors, and the calibration unit 22 uses the amount of deviation of the imaged pixels calculated by the calculator 21. Based on this, the calibration is executed so that the image pickup pixels imaged by the line sensors R, G, and B are matched.

According to the image pickup apparatus 100 of the first embodiment of the present invention, complicated setting in the calibration of the chromatic aberration of magnification can be automatically executed.

Since the image pickup apparatus 100 according to the first embodiment of the present invention can store the shift amount of the image pickup pixel as the correction data in the storage circuit 30 or the image storage circuit 60, the calibration is performed once. By generating the shift amount of the image pickup pixel as the correction data, when the normal image pickup is executed thereafter, the correction can be performed using the generated correction data.

Further, the image capturing apparatus 100 according to the first embodiment of the present invention stores the displacement amount of the image capturing pixel as the calibration data, so that, for example, the marker is not captured, and the calibration is performed using the calibration data. You may do it.

Further, the calibration area CA1 shown in FIG. 3A is not limited to the number of pixels in the horizontal direction (horizontal direction). For example, when 4000 pixels are arranged in a line in the left-right direction (horizontal direction), the center 3000 pixels of the calibration area CA1 are used for imaging, and the remaining 1000 pixels other than the center are used as calibration pixels. May be used.

The timing at which the image capturing apparatus 100 according to the first embodiment of the present invention captures an image of a marker is not particularly limited. For example, it is possible to take an image at an arbitrary timing when the user wants to execute the calibration. For example, the calibration may be performed once every day in the morning or at night, or when the lens 1 is replaced.

<2. Second Embodiment (Example 2 of Imaging Device)>
In the image pickup apparatus according to the second embodiment of the present invention, a marker is provided in a predetermined range of the calibration area in which the calibration is executed, and the calculation unit sets the marker in the predetermined range of the calibration area in which the marker is provided. The calibration unit calculates the shift amount of the imaging pixels between the line sensors, and the calibration unit matches the imaging pixels imaged by the respective line sensors of the two or more line sensors in a predetermined range of the calibration area in which the marker is provided. It is an imaging device that performs calibration so as to perform.

According to the imaging device of the second embodiment of the present invention, the calibration is executed so that the imaging pixels imaged by the respective line sensors of the two or more line sensors match in a predetermined range of the calibration region. Therefore, it is possible to perform more accurate calibration.

Here, an imaging device according to the second embodiment of the present technology will be described with reference to the chart CH3 illustrated in FIG.

A chart CH3 is shown in FIG. The chart CH3 has a calibration area CA3 for executing calibration. Further, the chart CH3 has markers provided in a predetermined range of the calibration area CA3. Here, the predetermined range is the entire range of the calibration area CA3.

In this case, the calculation unit 21 calculates the shift amount between one or more line sensors in the entire range of the calibration area CA3 where the marker MA4 (see FIG. 3C) is provided. Then, the calibration unit 22 is imaged by each of the line sensors R, G, and B in the entire range of the calibration area CA3 in which the marker MA4 (see FIG. 3C) is provided. Calibration is performed so that the imaging pixels match.

As described above, in the image pickup apparatus according to the second embodiment of the present invention, the image pickup pixels picked up by the respective line sensors R, G, and B in the predetermined range of the calibration area CA3 are displayed. Calibration can be performed to match.

As described above, according to the imaging device of the second embodiment of the present invention, the line sensor R, the line sensor G, and the line sensor B take images in a predetermined range of the calibration area CA3. It is possible to perform the calibration so that the image pickup pixels match. As a result, for example, the calibration of the lens 1 can be precisely performed, so that the accuracy of the captured image can be improved.

Further, by partially providing the marker MA4 as a predetermined range of the calibration area CA3, it is possible to partially execute the calibration. In this case, by arranging the marker MA4 at the place where the calibration is desired to be performed precisely, the calibration of that portion can be performed.

<3. Third Embodiment (Application Example of Imaging Device)>
An image pickup apparatus according to a third embodiment of the present invention is the image pickup apparatus according to the first embodiment, in which a marker is provided on a movable subject, and an imaging unit images the marker provided on the moving subject. , An imaging device.

According to the imaging apparatus of the third embodiment of the present invention, the imaging unit images the marker provided on the moving subject, so that the calibration can be executed when the marker is detected on the subject. ..

FIG. 7 shows the overall configuration of the third embodiment according to the present invention. FIG. 7 is an explanatory diagram showing an embodiment in which the image pickup apparatus according to the third embodiment of the present invention images a belt conveyor which is a subject, and executes a calibration when a marker is detected in the calibration area. is there. Unless otherwise specified, “upper” means the upper direction in FIG. 7, and “right” means the right direction in FIG. 7.

As shown in FIG. 7, the belt conveyor BC has calibration areas CA4 on both sides of the belt conveyor BC. Markers (markers MA5 and MA6) are provided in the calibration area CA4. The belt conveyor BC is, for example, a vertical belt conveyor.

For example, the imaging device 100 images the belt conveyor BC at a predetermined timing. The belt conveyor BC is rotatingly moved from top to bottom, and when the imaging apparatus 100 detects the markers (markers MA5 and MA6) in the calibration area CA4 along with the rotation movement of the belt conveyor BC. , Calibrate.

As described above, according to the imaging device 100 of the third embodiment of the present invention, when the imaging unit 10 images the markers (marker MA5, marker MA6) provided on the moving belt conveyor BC. , Calibration can be performed. As a result, in the third embodiment, the calibration of the imaging device 100 can be automatically executed at the predetermined timing desired by the user.

For example, in the third embodiment according to the present invention, the image pickup apparatus 100 is applied to an inspection camera, and a marker (marker MA5 is provided in the calibration area CA4 of the belt conveyor BC in accordance with the timing of starting or ending the inspection. By forming the markers MA6), the calibration can be executed at a desired predetermined timing.

Further, the first to third embodiments according to the present invention are not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present invention.

Further, the effects described in the present specification are merely examples and are not limited, and may have other effects.

For example, in the first to third embodiments, the image pickup apparatus 100 is configured to include the display 50 and the image storage circuit 60, but the present embodiment is not limited to this. For example, the imaging device 100 may not include the display 50 and the image storage circuit 60, but may include a separate display or an external image storage circuit via a wired or wireless network. In this case, the imaging device 100 can store the captured image to be stored in the image storage circuit 60 in an external image storage circuit, or can display the captured image on a separate display.

10 image pickup unit 20 processing circuit 21 calculation unit 22 calibration unit 30 storage circuit 40 input circuit 50 display 60 image storage circuit BC belt conveyor CH1, CH2, CH3, CH4 chart MA1, MA2, MA3, MA4 marker R, G, B line sensor

Claims (8)

An image capturing unit that captures an image of the marker through the lens and captures the marker with two or more line sensors having color filters of different colors for each color;
A calculating unit that separates the wavelength of the marker by the lens, and calculates a shift amount of an imaging pixel between the one or more line sensors that have been split.
A calibration unit that performs calibration based on the calculated shift amount of the image pickup pixels so that the image pickup pixels imaged by the line sensors of the two or more line sensors match each other;
An imaging device including. The markers are provided at substantially left and right ends of a calibration area for performing the calibration,
The calculation unit,
Calculating a shift amount of the imaging pixel between the one or more line sensors at substantially left and right end portions of the calibration area where the marker is provided,
The calibration unit,
The calibration is executed so that the image pickup pixels imaged by the respective line sensors of the two or more line sensors are matched at substantially left and right end portions of the calibration area where the markers are provided. The imaging device according to 1. The marker is provided substantially in the center of the calibration area for performing the calibration,
The calculation unit,
Calculating the shift amount of the imaging pixel between the one or more line sensors in the approximate center of the calibration area where the marker is provided,
The calibration unit,
3. The calibration is performed so that the image pickup pixels imaged by the line sensors of the two or more line sensors are substantially coincident with each other in substantially the center of the calibration area where the marker is provided. The imaging device according to. The calculation unit,
Calculating the amount of displacement of the imaging pixels between the one or more line sensors by interpolation,
The calibration unit,
The calibration is performed so that the image pickup pixels imaged by the line sensors of the two or more line sensors are matched based on the calculated shift amount of the image pickup pixels. The imaging device according to any one of items. The marker is provided in a predetermined range of a calibration area for performing the calibration,
The calculation unit,
Calculating a shift amount of the imaging pixel between the one or more line sensors in a predetermined range of the calibration area in which the marker is provided,
The calibration unit,
The calibration is performed such that the image pickup pixels imaged by the line sensors of the two or more line sensors are matched in a predetermined range of the calibration region where the marker is provided. The imaging device according to any one of 4 above. The image pickup apparatus according to claim 1, further comprising a storage unit that stores the amount of shift of the image pickup pixels. The marker is provided on a movable subject,
The imaging unit,
The imaging device according to claim 1, wherein the marker provided on the moving subject is imaged. The marker is
The image pickup apparatus according to claim 1, wherein the image pickup apparatus is formed of white and black lines.