Color information analysis device and program thereof, and spherical chart

Abstract

To provide a color information analysis device for supporting accurate color adjustment of a camera.SOLUTION: The color information analysis device 3 includes a designated position setting unit 31 that sets a designated position of a measurement target in a region of a spherical chart from a camera image obtained by the camera 2 capturing the spherical chart in which different colors are arranged in a period of a predetermined longitude of a spherical surface and which rotates about a rotation axis connecting opposite poles of a sphere, a color information processing unit 33 that acquires color information of the designated position from the camera image according to a rotation period of the spherical chart, stores the color information in a color information storage unit 32, and updates the color information, and a display unit 34 that displays the color information stored in the color information storage unit 32.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to a color information analysis device, a program therefor, and a spherical chart. [Background technology]

[0002] When taking pictures with a camera, the quality of the image is greatly affected by the state of the light source around the subject, and the camera settings such as exposure, white balance, etc. For this reason, conventionally, a board painted in a specified color called a chart (see, for example, Patent Document 1) is photographed in the same environment as the subject, and each setting of the camera is adjusted. Furthermore, the lighting conditions around the subject and camera settings are important in post-production for VFX (Visual Effects), etc. Therefore, in addition to the charts mentioned above, photographs of gray balls, mirror-finished metal spheres, etc. are often taken to record the shooting conditions. Furthermore, when photographing a subject from various distances and angles, there is a technology that records the relative positional relationship by placing a three-dimensional chart with a specified figure drawn on it in the field of view at the same time as the subject (see, for example, Patent Document 2). Furthermore, there is a conventional technique for adjusting the settings of multiple cameras using a cylindrical chart (see, for example, Non-Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-061494 [Patent Document 2] Patent No. 4590780 [Non-patent literature]

[0004] [Non-Patent Document 1] Kun Li, Qionghai Dai, Wenli Xu, "Collaborative color calibration for multi-camera systems", Signal Processing: Image Communication, 26 (1), pp. 48 - 60, (2011) Summary of the Invention [Problem to be solved by the invention]

[0005] When adjusting the camera settings, it is essential to have the flat chart facing the camera directly. However, when taking photographs under different shooting conditions such as the direction and intensity of the lighting, the surrounding environment, or the subject, the chart may need to be tilted relative to the camera for adjustment. However, with conventional charts, it is difficult to position the chart exactly facing the camera or tilt it at a desired angle relative to the camera. Therefore, conventional charts have the problem that even a slight deviation in the angle of the chart relative to the camera can cause a large change in the measurement value.

[0006] In addition, because the gray balls often used in VFX and other applications are a single color, it is only possible to adjust camera settings and record shooting conditions for that color. For example, even if the camera parameters are appropriate for the color of the ball used, there is a concern that a bright gray that is not white may become saturated and turn white when passed through the camera, resulting in a condition known as overexposure. Therefore, a method that allows measurements to be made for multiple colors at once has been desired.

[0007] The present invention has been made in consideration of these problems and demands, and has as its object to provide a color information analysis device and a program therefor, as well as a spherical chart, that support accurate color adjustment of a camera. [Means for solving the problem]

[0008] In order to solve the above problem, the color information analysis device of the present invention is a color information analysis device that analyzes color information of a spherical chart from a camera image taken by a camera of the spherical chart, on which different colors are arranged at a predetermined longitude cycle on the sphere and which rotates on an axis of rotation connecting the opposing poles of the sphere, and is configured to include a designated position setting unit, a color information processing unit, and a display unit.

[0009] In such a configuration, the color information analyzing device sets a designated position of the measurement target within the area of ​​the spherical chart in the camera image by the designated position setting unit. The color information analysis device then acquires color information at the specified position from the camera image in accordance with the rotation period of the spherical chart using the color information processing unit, and stores and updates the color information in the color information storage unit. This allows the color information analysis device to obtain different color information at the same position while keeping the position of the spherical chart fixed, without replacing the chart. Then, the color information analyzing device displays the color information stored in the color information storage unit on the display unit. The color information analyzing device can be operated by a program that causes a computer to function as a color information analyzing device.

[0010] In addition, in order to solve the above-mentioned problems, the spherical chart of the present invention is a spherical chart used for adjusting the color of a camera, and is configured to include a sphere on which different colors are arranged at predetermined longitude intervals on the surface of the sphere, a rotation drive unit that rotates the sphere on a rotation axis connecting the opposing poles of the sphere, a joint unit that is attached to a support that extends from the rotation axis and tilts the rotation axis, and legs that are attached to the support and support the sphere relative to an installation surface and adjust the height.

[0011] In this configuration, by rotating the spherical chart with the rotation drive unit, it becomes possible to obtain color information for different colors at the same coordinate position on the image captured by the camera. At this time, the positions on the image where color information is obtained have the same normal direction on the sphere, so color adjustment of the camera can be performed under the same conditions. Furthermore, the spherical chart can be easily positioned facing the camera because the center of the sphere on the camera image is the point facing the camera. [Effects of the Invention]

[0012] According to the present invention, different color information can be obtained at the same position on a camera image without changing the chart, which makes it possible to perform color adjustment of the camera with high precision. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 is a front view showing the configuration of a spherical chart according to an embodiment of the present invention. [Figure 2] 10A and 10B are diagrams illustrating examples of color schemes for spheres in a spherical chart according to an embodiment of the present invention. [Figure 3A] 10A and 10B are diagrams illustrating modified examples of color schemes of spheres in a spherical chart according to an embodiment of the present invention. [Figure 3B] 10A and 10B are diagrams illustrating modified examples of color schemes of spheres in a spherical chart according to an embodiment of the present invention. [Figure 3C] 10A and 10B are diagrams illustrating modified examples of color schemes of spheres in a spherical chart according to an embodiment of the present invention. [Figure 3D] 10A and 10B are diagrams illustrating modified examples of color schemes of spheres in a spherical chart according to an embodiment of the present invention. [Figure 4] FIG. 1 is a front view showing a state in which a spherical chart according to an embodiment of the present invention is tilted by a joint portion. [Figure 5] FIG. 10 is a front view showing a state in which the height of the spherical chart according to the embodiment of the present invention has been adjusted using legs. [Figure 6] 1A and 1B are diagrams showing an example of a spherical chart according to an embodiment of the present invention placed in a volumetric capture studio, where FIG. 1A is an XZ plane view and FIG. 1B is an XY plane view. [Figure 7] 1 is a block diagram showing a configuration of a color information analysis device according to an embodiment of the present invention. [Figure 8] FIG. 10 is an explanatory diagram for explaining a method for calculating the surface position of a sphere with respect to a normal line. [Figure 9] 10 is an explanatory diagram for explaining the target of color information acquired by a color information acquisition unit when a coordinate specification mode is designated as the analysis mode. FIG. [Figure 10] 10 is an explanatory diagram for explaining the target of color information acquired by a color information acquisition unit when a color designation mode is designated as the analysis mode. FIG. [Figure 11] FIG. 10 is an explanatory diagram of a modified example for explaining the target of color information acquired by the color information acquisition unit when a color designation mode is designated as the analysis mode. [Figure 12] 10 is a flowchart illustrating an operation of the color information analyzing device according to the embodiment of the present invention when the analysis mode is a coordinate specification mode. [Figure 13] 13 is a flowchart showing the operation of the measurement object coordinate determination process of FIG. 12. [Figure 14] 13 is a flowchart showing the operation of the color information acquisition process of FIG. 12. [Figure 15] 10 is a flowchart illustrating an operation of the color information analyzing device according to the embodiment of the present invention when the analysis mode is a color designation mode. DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. [Spherical Chart] The configuration of a spherical chart 1 according to an embodiment of the present invention will be described with reference to FIG.

[0015] The spherical chart 1 is a spherical chart used for color adjustment of a camera. The spherical chart 1 includes a sphere 10 , a rotation drive unit 11 , a joint unit 12 , and legs 13 .

[0016] The sphere 10 is an object to be photographed by a camera, and different colors are arranged at predetermined longitude intervals on the surface of the sphere. The sphere 10 is the polar point (10 N ,10 S ) and the rotation axis 10 XRotates around the center. The sphere 10 is colored in a color bar with different colors at predetermined longitude intervals, assuming that the shape is that of the Earth. For example, as shown in FIG. N The sphere surface is colored black, dark gray, light gray, and white at predetermined longitude intervals (22.5 degrees in the example of Figure 2). In this case, a quarter rotation of the sphere 10 indicates the period T.

[0017] The coloring of the surface of sphere 10 may not be based on equal longitude intervals, but may be different colors for each area obtained by slicing sphere 10A along a plane parallel to the axis of rotation, as shown in Fig. 3A. Furthermore, as shown in Fig. 3B, sphere 10B may be divided at the equator, assuming the shape of the Earth, and different colors may be assigned to each area obtained by slicing sphere 10B along a plane parallel to the axis of rotation. Even in this case, the rotating shaft 10 X When rotated in (Figure 1), each color has a periodicity.

[0018] Alternatively, as shown in Fig. 3C, the sphere 10 may be colored in a different color for each longitude, and in a certain longitude section, a predetermined color may be assigned as a marker MK for detecting the period. For example, a chromatic color may be used as the marker MK in an arrangement of achromatic colors. Alternatively, the sphere 10 may have a gradation as shown in Fig. 3D. In this case, one rotation of the sphere 10 corresponds to one period. The sphere 10 may be produced by, for example, coloring a white sphere and painting different colors on different sections of its surface, or by attaching materials such as metal, cloth, wood, or glass to different sections of its surface.

[0019] The rotation drive unit 11 rotates the sphere 10 at both opposing poles (10 N ,10 S ) and the rotation axis 10 X The sphere 10 is rotated by the A general rotary drive device may be used as the rotary drive unit 11. For example, a spindle motor in which a power source and a rotating unit are integrated may be used. The rotary drive unit 11 has a rotary shaft 10 at the tip of the spindle motor. X By attaching one end of the shaft and driving it, the sphere 10 is rotated. Furthermore, for example, the rotation driver 11 may incorporate a rotary encoder and output the rotation speed and other information as an electrical signal. This facilitates processing (cycle detection, etc.) in the color information analyzer 3 (FIG. 7) described below.

[0020] The joint 12 is connected to the rotation axis 10 X The rotating shaft 10 is attached to a support pillar extending from the X It is a joint mechanism that tilts the A general joint mechanism may be used for the joint unit 12. For example, a universal joint may be used for the joint unit 12. One end of a link connected to the rotation drive unit 11 is fixed to the universal joint, and by rotating the link, the rotation shaft 10 X can be tilted. Specifically, the joint 12 rotates the rotation axis 10 X By tilting the spherical chart 1, the sphere 10 will be tilted as shown in Figure 4. This allows the camera to capture more of the area near the equator when the sphere 10 of the spherical chart 1 is regarded as the Earth, depending on the position of the camera performing the color adjustment.

[0021] The leg 13 is connected to the rotation axis 10 X The leg 13 is attached to a support pole 13 connected to the joint 12, and supports the sphere 10 on the installation surface. P tripod 13 T It is fixed by. As shown in FIG. 5, the leg 13 is P Telescopic mechanism 13 S This extension mechanism 13 may be provided. S The height of the sphere 10 of the spherical chart 1 can be adjusted by the above.

[0022] An example of using this spherical chart 1 for color adjustment of a camera will be described. For example, as shown in Figure 6, a spherical chart 1 can be placed at the position of a subject to be photographed by multiple cameras 2 in a volumetric capture studio (hereinafter referred to as the studio), allowing color adjustment for each camera 2. Note that Figure 6(a) is a schematic diagram corresponding to a cross section parallel to the XZ plane when the studio is viewed from above. Figure 6(b) is a schematic diagram corresponding to a cross section parallel to the XY plane when the studio is viewed from the front. In this way, the spherical chart 1 can easily be positioned facing any camera 2. Of course, in addition to use in volumetric capture studios, the spherical chart 1 can also be used for color adjustments in cameras, replacing adjustments made with conventional flat charts.

[0023] [Configuration of color information analysis device] Next, the configuration of the color information analyzing device 3 according to the embodiment of the present invention will be described with reference to FIG.

[0024] The color information analysis device 3 analyzes the color information of a spherical chart 1 (Fig. 1) from a camera image taken by a camera 2 of the spherical chart 1 (Fig. 1), which has different colors arranged at predetermined longitude intervals on the spherical surface and rotates around an axis of rotation connecting the opposing poles of the sphere. The resolution and angle of view of the camera 2 are known, and the center of the sphere 10 of the spherical chart 1 is assumed to be located on the optical axis of the camera 2. Specifically, the color information analysis device 3 collects coordinates, colors, and normals as analysis results of the spherical chart 1 in a camera image of the spherical chart 1.

[0025] The color information analyzing device 3 collects information using different methods depending on the two analysis modes that are externally set by the user. One of the analysis modes is a mode (coordinate specification mode) in which the coordinates to be measured on the surface of the sphere 10 of the spherical chart 1 on the camera image are specified, and the color corresponding to those coordinates is collected from the rotating spherical chart 1. There are three ways to specify the coordinates to be measured.

[0026] The first coordinate specification method is to specify the coordinates directly on the camera image (direct specification). The second coordinate specification method is to specify a normal line (normal line specification). In this case, the coordinates on the camera image corresponding to the point on the surface of the sphere 10 having the specified normal line are identified as the coordinates to be measured. Note that the center of the spherical chart 1 is, more precisely, the center of the sphere 10. Hereinafter, the center of the spherical chart 1 refers to the center of the sphere 10. The third coordinate specification method is to specify the center of spherical chart 1 (center specification). The center of spherical chart 1 is always a point directly facing camera 2. In other words, the center position of spherical chart 1 on the camera image indicates the coordinates directly facing camera 2.

[0027] Another analysis mode is a mode (color designation mode) in which a color on the spherical chart 1 on the camera image is designated, and information on the area corresponding to that color is collected.

[0028] Here, the color information analysis device 3 includes an input unit 30, a designated position setting unit 31, a color information storage unit 32, a color information processing unit 33, and a display unit . The input unit 30 is used to input information designated by a user from outside via an input device (not shown) such as a keyboard or a mouse. The input unit 30 includes a coordinate input unit 300 , a normal input unit 301 , and a target color selection unit 302 . The coordinate input unit 300 and normal input unit 301 function when the analysis mode is the coordinate specification mode, and the target color selection unit 302 functions when the analysis mode is the color specification mode.

[0029] The coordinate input unit 300 is used to input the measurement coordinates of the spherical chart 1 on the camera image. The coordinate input unit 300 accepts input of the coordinates at which measurement is desired on the spherical chart 1 displayed on the display device 4. The coordinate input unit 300 may input coordinate values ​​of the camera image directly, or may specify a position via an input device such as a mouse. The coordinate input unit 300 stores the input measurement target coordinates in the color information storage unit 32.

[0030] The normal input unit 301 is used to input information about the normal of the spherical chart 1. This normal information is the elevation angle and azimuth angle relative to the center of the spherical chart 1, or a three-dimensional normal vector. In the case of a conventional flat chart, this normal indicates the direction of the perpendicular to the surface of the chart. A normal input unit 301 inputs normal information (elevation angle and azimuth angle, or normal vector) via an input device. The normal input unit 301 stores the input normal information in the color information storage unit 32 .

[0031] The target color selection unit 302 selects the color of the measurement target of the spherical chart 1 on the camera image. For example, the target color selection unit 302 selects a color at a position by specifying the position via an input device such as a mouse. The object color selection unit 302 outputs the selected object color and its coordinate position to the designated position setting unit 31 .

[0032] The designated position setting unit 31 sets the designated position of the measurement target within the area of ​​the spherical chart 1 in the camera image. The designated position setting unit 31 calculates the coordinates of the measurement target, which are the designated position, according to the analysis mode set externally. Here, the designated position setting unit 31 includes a spherical chart detection unit 310 , a center point setting unit 311 , a target color position setting unit 312 , and a normal position conversion unit 313 .

[0033] The spherical chart detection unit 310 detects the spheres 10 of the spherical chart 1 in the camera image. The spherical chart detection unit 310 detects the position (center) and size (radius) of a circle that represents the shape of the sphere 10 from the camera image. A general method can be used to detect the circle from within this image. For example, the spherical chart detection unit 310 can detect the circle using a Hough transform.

[0034] In order to remove any circular objects other than the spherical chart 1 from the camera image, it is preferable that the spherical chart detection unit 310 detects the spheres 10 of the spherical chart 1 in advance using a blue or green background. Alternatively, on the assumption that the sphere 10 of the spherical chart 1 is located on the optical axis of the camera 2, the spherical chart detection unit 310 may detect a circle close to the center of the image as the sphere 10. Alternatively, the background may be photographed once before the spherical chart 1 is installed, and the spherical chart detection unit 310 may fill in everything except the spherical chart 1 by background subtraction. Alternatively, on the assumption that the sphere 10 is rotating, the spherical chart detection unit 310 may detect the sphere 10 by taking the difference from the image several frames earlier. The spherical chart detection unit 310 outputs the position (center) and size (radius) of the detected sphere to the center point setting unit 311 and the target color position setting unit 312.

[0035] The center point setting unit 311 sets the coordinates of the center of the sphere 10 in the camera image detected by the spherical chart detection unit 310 as a designated position. This center point setting unit 311 operates when the coordinate specification mode is specified as the analysis mode and the center specification is specified as the coordinate specification method. The center point setting unit 311 stores the set designated position in the color information storage unit 32.

[0036] The target color position setting unit 312 sets the measurement target color and its coordinate position selected by the target color selection unit 302 as the target color and specified position within the circular shape of the sphere 10 in the camera image detected by the spherical chart detection unit 310. This target color position setting unit 312 operates when the color specification mode is specified as the analysis mode. The target color position setting unit 312 stores the set target color and the designated position in the color information storage unit 32.

[0037] The normal position conversion unit 313 calculates the pixel position on the surface of the sphere 10 on the camera image corresponding to the normal information stored in the color information storage unit 32, and sets it as the designated position. This normal position conversion unit 313 operates when the coordinate specification mode is specified as the analysis mode and normal specification is specified as the coordinate specification method. The normal position conversion unit 313 stores the set designated position in the color information storage unit 32 in association with information on the normal before conversion. When the coordinate specification mode is specified as the analysis mode and the direct specification is specified as the coordinate specification method, the coordinate position stored in the color information storage unit 32 via the coordinate input unit 300 becomes the specified position of the measurement target.

[0038] Here, a method for calculating pixel positions on the spherical surface in a camera image from normal information will be described with reference to Fig. 8. Note that the elevation angle and azimuth angle, which are normal information, are calculated using the same method, with only the difference being the vertical or horizontal direction, so only the elevation angle will be described here.

[0039] Figure 8 shows the positional relationship between the sphere 10 and the camera 2. Here, c is the center of the sphere 10, o is the lens center of the camera 2, a and a' are points corresponding to the edges of the sphere 10 on the camera image, and r is the radius of the sphere 10. θ n is normal information (here, elevation angle), p is a point (specified position) corresponding to the spherical surface of the sphere 10 corresponding to the normal, and p' is the foot of the perpendicular line from p to the optical axis (straight line oc) of the camera 2. r is the angle formed by point coa (point coa') and is the angle from the optical axis corresponding to the radius of the sphere 10 on the camera image. p is the angle formed by point cop from the optical axis corresponding to the position of point p on the camera image. where L xy When is a line segment connecting point x and point y, the relationship between the following equations (1) to (4) holds.

[0040]

number

number

number

number

[0041] From equations (3) and (4), the following equation (5) holds.

[0042]

number

[0043] Furthermore, from equations (1), (2), and (5), the following equation (6) holds.

number

[0044] where θ n is normal information (here, elevation angle) specified by the user, and is known information. Also, θ r is the angle corresponding to the edge of the sphere 10 on the camera image. If the angle of view of the camera 2 and the resolution of the camera image are known, the distance from the optical axis on the camera image and the angle from the optical axis can be converted.

[0045] Therefore, the normal position conversion unit 313 calculates the angle of view of the camera 2, the distance from the center to the edge of the sphere 10 on the camera image (the radius of the circular shape of the sphere 10 on the camera image), and the angle θ r Ask for. Then, the normal position conversion unit 313 calculates θ by the arctangent of equation (6). p Calculate the angle θ pThe distance from the center of the circular shape of the sphere 10 on the camera image corresponding to the angle of elevation θ of the specified normal is calculated. n The vertical pixel position on the camera image corresponding to Similarly, the normal position conversion unit 313 identifies the horizontal pixel position on the camera image that corresponds to the azimuth angle of the specified normal. Returning to FIG. 7, the configuration of the color information analysis device 3 will be further described.

[0046] The color information storage unit 32 stores the color information of the designated position set by the designated position setting unit 31 . The color information storage unit 32 can be configured with a general storage medium such as a hard disk or semiconductor memory. The color information storage unit 32 stores, as color information, coordinates of the camera image that are the designated position of the measurement target, and information on the color and normal corresponding to the coordinates.

[0047] The color information processing unit 33 acquires color information at a specified position from the camera image in accordance with the rotation period of the spherical chart 1 and stores the information in the color information storage unit 32 . Here, the color information processing unit 33 includes a color information acquisition unit 330 , a periodic update unit 331 , and a period detection unit 332 .

[0048] The color information acquisition unit 330 acquires color information of the designated position set by the designated position setting unit 31 from the camera image. When the coordinate specification mode is set as the analysis mode, the color information acquisition unit 330 acquires color information corresponding to the specified position stored in the color information storage unit 32 from the camera image based on the period detected by the period detection unit 332.

[0049] For example, as shown in FIG. 9, the position P A is specified, the color information acquisition unit 330 determines the position P based on the period detected by the period detection unit 332. A As color information, black, dark gray, light gray, and white color information are acquired. This allows the spherical chart 1 to function as a chart similar to the flat chart 5.

[0050] When the color designation mode is set as the analysis mode, the color information acquisition unit 330 moves the designated position stored in the color information storage unit 32 on the camera image based on the period detected by the period detection unit 332, and acquires color information at the pixel position after the movement.

[0051] For example, as shown in FIG. 10, the position P B is specified, the color information acquisition unit 330 determines the position P based on the period detected by the period detection unit 332. B The color information of the sphere 10 is acquired, and the designated position of the sphere 10 on the rotating spherical chart 1 is moved in sequence to acquire color information of the same position on the sphere 10. This allows the color information acquisition unit 330 to acquire color information along the curve 6 of the sphere 10.

[0052] In addition, when the color specification mode is set as the analysis mode, in addition to the color information of the specified position stored in the color information storage unit 32, color information of an area with the same color scheme including the specified position may be obtained according to the known color scheme of the sphere 10.

[0053] For example, as shown in FIG. 11, the position P C is specified, the color information acquisition unit 330 calculates the position P based on the known color scheme of the sphere 10 and the period detected by the period detection unit 332. C Color information and position P C The color information acquisition unit 330 acquires color information of each pixel in the area S to which the color information acquisition unit 330 belongs. At this time, if an area S with the same color scheme exists at a different latitude, or if an area S with the same color scheme exists in a different period other than the period T as shown in FIG. 2, the color information acquisition unit 330 acquires color information of that area. This allows the color information acquisition unit 330 to acquire color information along the curved surface 7 of the sphere 10. The color information acquisition unit 330 stores the acquired color information of the specified coordinates in the color information storage unit 32.

[0054] The period-based updating section 331 updates the color information stored in the color information storage section 32 by the color information acquisition section 330 based on the period detected by the period detection section 332 . The periodic update unit 331 updates and organizes the color information stored in the color information storage unit 32 according to the period, such as by deleting color information collected in the previous period or by deleting duplicate data of the same color information.

[0055] The cycle detection unit 332 detects the cycle of rotation of the sphere 10 of the spherical chart 1 on the camera image. The method for detecting the rotation period of the sphere 10 is not particularly limited, and various methods can be used. For example, if the rotation speed of the spherical chart 1 is known or can be obtained from the rotation drive unit 11 (see FIG. 1) of the spherical chart 1, the period of the spherical chart 1 is detected according to the rotation speed and the frame rate of the camera 2. This period is not limited to one rotation of the sphere 10, but is detected according to a predetermined color scheme, as shown in FIG. 2. In the case of FIG. 2, the period detection unit 332 detects a quarter rotation and sets this as the period T.

[0056] The cycle detection unit 332 may detect the cycle not only based on the rotation speed of the spherical chart 1 but also based on the change in color of the sphere 10 on the camera pixels. Alternatively, the cycle detection unit 332 may detect the cycle using a marker MK composed of a specific color for detecting the cycle, as shown in FIG. 3C. Alternatively, the cycle detection unit 332 may set the cycle externally. Note that if the spherical chart 1 is a chart with a gradation as shown in FIG. 3D, the cycle may be detected by detecting the color difference as the gradation changes from white to black as the sphere 10 makes one rotation. Alternatively, the cycle detection unit 332 may detect the cycle based on a signal from the rotation drive unit 11 of the spherical chart 1. The cycle detection unit 332 outputs the detected (or set) cycle start point to the color information acquisition unit 330 and the cycle-specific update unit 331.

[0057] The display unit 34 displays the color information stored in the color information storage unit 32 on the display device 4. That is, the display unit 34 displays the coordinates, colors, and normals stored in the color information storage unit 32 in association with each other. For example, the display unit 34 displays the color information in a graph, like a waveform monitor.

[0058] The display unit 34 may also be configured to simulate a flat chart 5 as shown in FIG. 9 and display it superimposed on the camera image. In addition, the display unit 34 may superimpose on the camera image a linear color distribution of the curve 6 along the sphere 10 shown in Figure 10, or a two-dimensional color distribution of the curved surface 7 along the sphere 10 shown in Figure 11 viewed in plan.

[0059] When the analysis mode is the coordinate specification mode and normal information is not stored in the color information storage unit 32, the display unit 34 calculates the normal from the coordinate position, for example, by the inverse conversion of the normal position conversion unit 313. A configuration for performing the inverse conversion of the normal position conversion unit 313 may be provided separately as a normal position inverse conversion unit (not shown), and the display unit 34 may request the inverse conversion.

[0060] With the above-described configuration, the color information analysis device 3 can acquire color information when the spherical chart 1 is precisely positioned directly in front of the camera 2. This allows the color information analysis device 3 to support highly accurate adjustment of the camera 2. Furthermore, by using a spherical chart 1 with a plurality of colors, the color information analyzing device 3 can simultaneously measure a plurality of colors under the same conditions. The color information analyzing device 3 can be operated by a program (color information analyzing program) that causes a computer (not shown) to function as each of the above-mentioned units.

[0061] [Color information analyzer operation] Next, the operation of the color information analyzing device 3 according to the embodiment of the present invention will be described with reference to FIGS. 12 to 15 (and for the configuration, refer to FIG. 7 as appropriate).

[0062] First, with reference to FIG. 12, the operation when the analysis mode set externally is the coordinate specification mode will be described. In step S1, the color information analyzing device 3 determines the measurement target coordinates based on the designation method, which is a parameter of the analysis mode set externally (measurement target coordinate determination process).

[0063] Here, the detailed operation of step S1 will be described with reference to FIG. In step S10, the designated position setting unit 31 inputs a method for designating the measurement target coordinates as a parameter of the analysis mode. In step S11, the designated position setting unit 31 determines whether the designation method input in step S10 is direct designation, normal line designation, or center designation.

[0064] If the designation method in step S11 is direct designation, then in step S12, the target coordinates of the spherical chart 1 on the camera image designated by the user are input via the coordinate input unit 300. The input measurement target coordinates are then stored in the color information storage unit 32.

[0065] If the specification method in step S11 is normal specification, then in step S13, information about the normal of the spherical chart 1 specified by the user is input via the normal input unit 301. The input normal information is then stored in the color information storage unit 32. In step S14, the normal position conversion unit 313 calculates the pixel position (coordinates) on the surface of the sphere 10 on the camera image corresponding to the normal information. The pixel position calculated here is stored in the color information storage unit 32 as the measurement target coordinate in association with the normal information input in step S13.

[0066] If the designation method in step S11 is center designation, then in step S15, the designated position setting unit 31 detects the center point of the sphere 10 on the camera image. That is, the spherical chart detection unit 310 detects the position (center) and size (radius) of a circle that indicates the shape of the sphere 10 from the camera image. Then, the center point setting unit 311 stores the coordinates of the center of the sphere 10 in the camera image in the color information storage unit 32 as the measurement target coordinates. Then, the color information analyzing device 3 proceeds to step S2 (FIG. 12). Returning to FIG. 12, the overall operation of the color information analyzing device 3 will be described.

[0067] In step S2, the color information analysis device 3 acquires color information from the video input from the camera 2 (color information acquisition process). Here, the detailed operation of step S2 will be described with reference to Fig. 14. Note that in step S2, although not shown, the cycle detection unit 332 sequentially detects the beginning (start point) of the cycle of the chart from the video (camera image) input from the camera 2. In step S20, the color information acquisition unit 330 receives the video input from the camera 2 for each frame (camera image).

[0068] In step S21, the color information acquisition unit 330 determines whether the cycle detection unit 332 has detected the beginning (start point) of the cycle in the camera image. If the start of the cycle is detected (Yes in step S21), then in step S22, color information acquisition unit 330 sets "0" to variable i, which is the array element number for storing color information. On the other hand, if the camera image is not the first in the cycle (No in step S21), in step S23, the color information acquisition unit 330 adds "1" to the variable i. Note that this step S23 operates after the variable i is set to "0" in step S22.

[0069] In step S24, the color information acquisition unit 330 acquires color information of the measurement object coordinates stored in the color information storage unit 32 from the input camera image. In step S25, the color information acquisition unit 330 stores the color information acquired in step S24 in the array of the ith memory specified by the variable i in the color information storage unit 32. Then, the color information analyzing device 3 proceeds to step S3 (FIG. 12). Returning to FIG. 12, the overall operation of the color information analyzing device 3 will be described.

[0070] In step S3, the periodic update unit 331 updates the color information stored in the color information storage unit 32 according to the period, such as by deleting color information collected in the previous period or by deleting duplicate data of the same color information. In step S4, the display unit 34 displays the color information stored in the color information storage unit 32 on the display device 4. By the above operation, the color information analyzing device 3 can simultaneously measure color information of a plurality of colors at designated coordinates from the image of the spherical chart 1 captured by the camera 2.

[0071] Next, with reference to FIG. 15, the operation when the analysis mode set externally is the color designation mode will be described. In step S100, the target color selection unit 302 selects the color of the measurement target of the spherical chart 1 and its coordinate position (specified position) on the camera image, and stores them in the color information storage unit 32.

[0072] Then, the color information acquisition unit 330 repeats the following steps S101 and S102 from the start to the end of the cycle detected by the cycle detection unit 332. That is, in step S101, the color information acquisition unit 330 inputs a camera image. In step S102, the color information acquisition unit 330 moves the designated position stored in the color information storage unit 32 on the camera image based on the period detected by the period detection unit 332, and acquires color information at the pixel position after the movement (see FIG. 10 ). Then, the color information acquisition unit 330 stores the acquired color information in the color information storage unit 32. After one cycle is completed, the display unit 34 displays the color information stored in the color information storage unit 32 on the display device 4 in step S103. By the above operation, the color information analyzing device 3 can simultaneously measure color information at a plurality of positions for a specified color from the image captured by the camera 2 that photographed the spherical chart 1.

[0073] Although the configuration and operation of the color information analyzing device 3 according to the embodiment of the present invention have been described above, the present invention is not limited to this embodiment. Here, the color information analysis device 3 has been described as operating in two analysis modes, the coordinate specification mode and the color specification mode, but it may have a simple configuration that operates in only one of the modes. For example, when operating in only the coordinate specification mode, the target color selection unit 302 and the target color position setting unit 312 can be omitted from the configuration. [Explanation of symbols]

[0074] 1. Spherical Chart 10 spheres 11 Rotation drive unit 12 Joints 13 Legs 2 Cameras 3 Color information analysis device 30 Input section 300 Coordinate input section 301 Normal input section 302 Target color selection section 31 Specified position setting section 310 Spherical chart detection unit 311 Center point setting section 312 Target color position setting section 313 Normal position conversion part 32 Color information storage section 33 Color information processing section 330 Color information acquisition section 331 Periodic update section 332 Period detection unit 34 Display section 4 Display device

Claims

1. A color information analysis device that analyzes color information of a spherical chart from a camera image taken by a camera of the spherical chart, which is colored in different colors at predetermined longitude intervals on the surface of the sphere and rotates around an axis of rotation connecting the opposing poles of the sphere, comprising: a designated position setting unit that sets a designated position of a measurement target within the area of ​​the spherical chart in the camera image; a color information processing unit that acquires color information of the specified position from the camera image in accordance with the rotation cycle of the spherical chart, stores the information in a color information storage unit, and updates the information; a display unit that displays the color information stored in the color information storage unit; A color information analysis device comprising:

2. The designated position setting unit a spherical chart detection unit that detects the sphere of the spherical chart in the camera image; a center point setting unit that, when the center of the sphere is designated as the designated position, sets the center point of the sphere in the camera image as the designated position; a normal position conversion unit that, when a normal to the sphere is designated as the designated position, calculates a pixel position on the camera image corresponding to the normal and sets the pixel position as the designated position; 2. The color information analysis device according to claim 1, further comprising:

3. The designated position setting unit a target color position setting unit that, when a target color is designated as the designated position, sets a pixel position on the spherical chart on the camera image corresponding to the designated target color as the designated position; The color information analysis device according to claim 2 , further comprising:

4. 2. The color information analysis device according to claim 1, wherein the color information processing unit acquires color information by moving the specified position in accordance with a rotation period of the spherical chart.

5. A program for causing a computer to function as the color information analysis device according to any one of claims 1 to 4.

6. A spherical chart used to adjust the color of a camera, A sphere with different colors arranged at predetermined longitude intervals on the sphere surface; a rotation drive unit that rotates the sphere on a rotation axis connecting the opposing poles of the sphere; a joint portion provided on a support column extending from the rotation shaft and tilting the rotation shaft; a leg portion provided on the support column for supporting the sphere relative to an installation surface and for adjusting the height of the sphere; A spherical chart comprising:

Images