Control method, control device, display system, and computer program

Abstract

This control method controls each of first and second display devices by using a control device in a display system for displaying one video by using the display devices. With an arithmetic circuit of the control device, this control method: acquires information regarding a color gamut of each of the display devices; extracts an xy chromaticity point of at least one vertex among the RGB vertices in the color gamut of the first display device as a first xy chromaticity point to be adjusted; extracts an xy chromaticity point of at least one vertex among the RGB vertices in the color gamut of the second display device as a second xy chromaticity point to be adjusted; calculates a common xy chromaticity point within a common range of the color gamuts of the first and second display devices; displays, on the first display device, a video in a color gamut adjusted on the basis of the first xy chromaticity point to be adjusted and the common xy chromaticity point; and displays, on the second display device, a video in a color gamut adjusted on the basis of the second xy chromaticity point to be adjusted and the common xy chromaticity point.

Description

Control method, control device, display system, and computer program

[0001] The present disclosure relates to a control method, a control device, a display system, and a computer program for controlling a plurality of display devices in a display system that combines a plurality of display devices to display one video content.

[0002] There are display systems that combine images displayed by multiple display devices to create a single image. In such display systems, if the images displayed by each display device are not balanced properly, the combined image may appear unnatural because the images displayed by each display device do not harmonize.

[0003] In such a display system, at least one of the multiple display devices may be adjusted to control the synthesized image so that it does not look unnatural (see, for example, Patent Document 1). Alternatively, the display state of each display device may be photographed with an imaging device, and the photographed image may be used to control the images of each display device so that they are unified.

[0004] Japanese Patent Application Laid-Open No. 2002-215517

[0005] The display system according to the present disclosure suppresses degradation in the quality of images from multiple display devices.

[0006] A control method disclosed herein controls each display device using a control device in a display system that displays a single image using first and second display devices. The control method includes acquiring color gamut information of each display device using an arithmetic circuit in the control device, extracting an xy chromaticity point of at least one vertex among the RGB vertices in the color gamut of the first display device as a first xy chromaticity point to be adjusted, extracting an xy chromaticity point of at least one vertex among the RGB vertices in the color gamut of the second display device as a second xy chromaticity point to be adjusted, calculating a common xy chromaticity point that is within a common range of the color gamuts of the first and second display devices, displaying an image in the color gamut adjusted based on the first xy chromaticity point and the common xy chromaticity point on the first display device, and displaying an image in the color gamut adjusted based on the second xy chromaticity point and the common xy chromaticity point on the second display device.

[0007] Such general and specific aspects may be realized by a system, a method, and a computer program, as well as a combination thereof.

[0008] The control method, control device, display system, and computer program of the present disclosure can suppress degradation of video quality in a display system that displays video content using multiple display devices.

[0009] 1A is an xy chromaticity diagram; FIG. 1B is an enlarged view of a portion of the xy chromaticity diagram of FIG. 1A; FIG. 1C is a schematic diagram showing a display system according to an embodiment; FIG. 2A is a block diagram showing the configuration of the control device of FIG. 2B; FIG. 2C is a block diagram showing the configuration of the projection device of FIG. 2B; FIG. 3A is a flowchart illustrating processing executed by the control device according to an embodiment; FIG. 3B is a flowchart illustrating control processing executed by the control device; FIG. 3C is a flowchart illustrating a portion of the chromaticity point of the B primary color on the xy chromaticity diagram illustrating control processing according to an embodiment; FIG. 3D is an example of an operation screen displayed by the control device; FIG. 3E is another example of an operation screen displayed by the control device; FIG. 1D is a schematic diagram showing a display system according to Modification 1; FIG. 1E is a flowchart illustrating processing executed by the control device according to Modification 1; FIG. 1F is a schematic diagram showing a display system according to Modification 2; FIG. 1F is a flowchart illustrating processing executed by the control device according to Modification 2; FIG. 1F is a flowchart illustrating processing executed by the control device according to Modification 3; 13 is a common B primary color point Pb in the xy chromaticity diagram shown in FIG. 11. FIG. 14 is an example of an operation screen used in a control device according to Modification 3. FIG. 15 is an example showing first and second target chromaticity point candidates determined from values ​​input to the operation screen shown in FIG. 14. FIG. 16 is an example of a first image candidate displayed by the control device of FIG. 13. FIG. 17 is an example of a second image candidate displayed by the control device of FIG. 13. FIG. 18 is an example of a control device in which a first image candidate and a second image candidate are simultaneously displayed. FIG. 19 is an example showing a range used to determine first and second target chromaticity points in a control device according to Modification 4. FIG. 20 is an example showing first and second target chromaticity points determined by a control device according to Modification 4.

[0010] [Embodiments] Hereinafter, embodiments of the present disclosure will be described using the drawings, with appropriate reference to the drawings. However, in the detailed description, unnecessary parts of the description of the prior art and substantially identical configurations may be omitted. This is for the sake of simplicity. Furthermore, the following description and the accompanying drawings are disclosed to enable those skilled in the art to fully understand the present disclosure, and are not intended to limit the subject matter of the claims.

[0011] The control method, control device, display system, and computer program according to the present disclosure are used to adjust each display device in a display system that combines multiple images displayed by multiple display devices to project a single video content. Specifically, the control method, control device, display system, and computer program according to the present disclosure can be used to control multiple display devices. Specifically, the control method, control device, display system, and computer program control the multiple display devices so that the color gamuts of the multiple display devices are unified.

[0012] The spectral sensitivity of the image capture device and the human eye is different, so even if the images displayed by each display device are adjusted to favorable conditions on the captured image obtained by the image capture device, the images displayed by each display device may not harmonize when viewed visually by a human.

[0013] Furthermore, as a result of controlling the images displayed on each display device to be uniform, the color gamut of the images displayed by the entire display system may become narrower, resulting in images that lack vividness.

[0014] For example, when multiple display devices are used in combination, the color gamut differs for each display device. This is because, for example, even display devices of the same model have individual differences within the tolerance. Furthermore, when display devices of different models are combined, differences in the color gamut for each display device are likely to occur between the different models. Furthermore, even if the color gamuts of multiple display devices are matched, changes in the color gamut may occur due to deterioration over time. Specifically, the spectral shapes of the light sources used by the multiple display devices may not match. Such differences in the spectral shapes of the light sources may result in differences in the color gamut.

[0015] According to the display system of the present disclosure, the color gamuts of images from multiple display devices can be controlled so that they appear harmonized to the human eye.

[0016] Furthermore, the display system according to the present disclosure can prevent the color gamut of images from multiple display devices from becoming so narrow that the images appear dull to the human eye.

[0017] In this disclosure, the term "color gamut" refers to the range of colors that can be displayed by a display device. The color gamut can be represented by a diagram known as an xy chromaticity diagram, as shown in FIG. 1A. For example, the color gamut of a display device uses a color gamut known as the sRGB color gamut. The horseshoe shape shown in FIG. 1A represents the entire range of chromaticities that humans can perceive. The triangle shown in FIG. 1A represents the color gamut that the display device can display. In FIG. 1A, each vertex of the triangle represents an RGB primary color that the display device can display. The vertex with the smallest x and y values ​​is the B primary color point representing the B (blue) primary color. The vertex with the largest x value is the R primary color point representing the R (red) primary color. The vertex with the largest y value is the G primary color point representing the G (green) primary color. The vertices of a triangle are sometimes referred to as "RGB primary color points." The example shown in FIG. 1A includes two triangles. Each triangle represents an RGB primary color that a different display device can display. 1B is an enlarged view of the rectangular portion of the vertex representing the B primary color in FIG. 1A. As shown in FIG. 1B, the points P1b and P2b representing the B primary color are different because the primary colors that can be displayed differ depending on the display device. Specifically, as shown in FIG. 1B, the points P1b and P1b representing the B primary color are different due to differences in the light source of each display device. For example, even if the light sources of multiple display devices are the same model, the wavelength distributions of the light sources are not completely identical, resulting in differences in the color gamuts of each display device.

[0018] In this disclosure, a point indicating coordinates on the xy chromaticity diagram is referred to as an "xy chromaticity point."

[0019] <Display System> As shown in FIG. 2A , a display system 1 according to an embodiment includes a control device 10, multiple projection devices 20A and 20B, a luminance and chromaticity measuring device 30, and a network 40. Each projection device 20A and 20B is controlled by the control device 10 to project an image onto a screen 50. Each projection device 20A and 20B projects the image onto a pre-designated area. The dashed lines in FIG. 2A indicate the area onto which the image is projected. This allows the display system 1 to generate a single image content as a whole. In this display system 1, the control device 10 controls each projection device 20A and 20B by adjusting parameters related to projection by each projection device 20A and 20B. For example, the control device 10 can adjust the color gamut of the image projected by each projection device 20A and 20B.

[0020] 2B , the control device 10 is an information processing device including an arithmetic circuit 11, an input device 12, an output device 13, a communication circuit 14, and a storage device 15. The control device 10 acquires the chromaticity and / or luminance of the RGB primary color images projected by each of the projection devices 20A, 20B, which are acquired by the luminance and chromaticity measurement device 30, and can control the chromaticity and / or luminance of each of the projection devices 20A, 20B.

[0021] The arithmetic circuit 11 is a controller that controls the entire control device 10. For example, the arithmetic circuit 11 reads and executes a control program P stored in the storage device 15 to realize various processes related to the display of each of the projection devices 20A and 20B. The arithmetic circuit 11 may be various processors such as a CPU, an MPU, a GPU, an FPGA, a DSP, an ASIC, or a dedicated hardware circuit.

[0022] The input device 12 is used for user operations and data input. The input device 12 may be, for example, an operation button, a keyboard, a mouse, a touch panel, a microphone, etc. The output device 13 is used for outputting processing results and data. In the following description, the output device 13 is assumed to be a display.

[0023] The communication circuit 14 performs data communication with the projection devices 20A and 20B and the luminance and chromaticity measuring device 30. The data communication is performed wired and / or wirelessly, and may be in accordance with, for example, a known communication standard. For example, wired data communication may be performed by using a communication controller of a semiconductor integrated circuit that operates in accordance with the Ethernet (registered trademark) standard and / or the USB (registered trademark) standard as the communication circuit 14. Wireless data communication may be performed by using a communication controller of a semiconductor integrated circuit that operates in accordance with the IEEE 802.11 standard for wireless local area networks (LANs) and / or the fourth-, fifth-, and sixth-generation mobile communication systems, known as 4G, 5G, and 6G, for mobile communication.

[0024] The storage device 15 is a recording medium for recording various information. The storage device 15 is realized by, for example, a RAM, a ROM, a flash memory, an SSD (Solid State Drive), a hard disk drive, or other storage devices, or an appropriate combination thereof. The storage device 15 stores a control program P, which is a computer program executed by the arithmetic circuit 11. The storage device 15 can also store measurement results 151 and an xy chromaticity diagram 152. The measurement results 151 are measured by the luminance and chromaticity measuring device 30. The xy chromaticity diagram 152 is generated by the arithmetic circuit 11.

[0025] <Projection Device> The projection devices 20A and 20B project images transmitted from an information processing device such as the control device 10 onto a screen. At this time, each of the projection devices 20A and 20B projects an image onto a different projection area of ​​the screen 50, thereby creating a single image content. Furthermore, each of the projection devices 20 and 20B receives a different image and projects the image, thereby generating a single image content.

[0026] As shown in FIG. 2C, the first projection device 20A has a video interface (I / F) 21, a video processing unit 22, a chromaticity adjustment unit 23, a projection processing unit 24, a projection unit 25, a control interface (I / F) 26, and a control circuit 27.

[0027] The video interface 21 may be a receiving circuit that receives a video signal to be displayed from an external device. The video interface 21 may also be a conversion circuit that converts the video signal into a standard such as HDMI (High-Definition Multimedia Interface) or SDI (Serial Digital Interface). The video interface 21 then transmits the received and converted video signal to the video processing unit 22.

[0028] The video processing unit 22 converts the video signal received from the video interface 21 into a common signal format (e.g., RGB image) that can be handled by a downstream processing unit. The video processing unit 22 also cancels the gamma characteristic of the received video signal. By canceling the gamma characteristic of the video signal, the downstream chromaticity adjustment unit 23 can handle the video signal in a linear color space. The video processing unit 22 transmits the video signal, whose signal format has been converted and whose gamma characteristic has been canceled, to the chromaticity adjustment unit 23.

[0029] The chromaticity adjustment unit 23 adjusts the chromaticity of the video signal received from the video processing unit 22 to a desired chromaticity. The adjustment method may be, for example, the method disclosed in Japanese Patent Application Laid-Open No. 2002-116749. The chromaticity adjustment unit 23 then transmits the video signal with the adjusted chromaticity to the projection processing unit 24.

[0030] The projection processing unit 24 converts the video signal received from the chromaticity adjusting unit 23 into a video signal suitable for projection. The projection processing unit 24 also transmits the converted video signal to the projection unit 25.

[0031] The projection unit 25 projects the received video signal onto the screen 50. The projection unit 25 includes an optical mechanism for projecting the video. Specifically, the optical mechanism may include a light source such as a laser diode, an LED, or a lamp. The optical mechanism may also include an optical unit including a light modulation element such as a liquid crystal element or a DMD (Digital Mirror Device) that modulates the light emitted from the light source, and a projection lens system that guides the video light modulated by the light modulation element to the projection surface.

[0032] The control interface (I / F) 26 is connected to the control device 10 via a network 40. The control interface 26 transmits a control signal received from the control device 10 to a control circuit 27.

[0033] The control circuit 27 is a controller that controls each of the units 21 to 25 in accordance with control signals received from the control device 10 via the control interface 26. The control circuit 27 may be any of various processors such as a CPU, an MPU, a GPU, an FPGA, a DSP, an ASIC, or a dedicated hardware circuit.

[0034] The second projection device 20B is the same as the first projection device 20A. Therefore, a description using illustrations will be omitted. In the following description, when there is no need to distinguish between them, they may be simply referred to as the projection device 20.

[0035] <Luminance and chromaticity measuring device> The luminance and chromaticity measuring device 30 is a device capable of measuring the luminance and chromaticity of at least a portion of the image projected by each projection device 20. For example, in Fig. 2A, the dashed-dotted circles F11 and F22 in the projected image are ranges for which luminance and chromaticity are measured by the luminance and chromaticity measuring device 30. A general device capable of measuring luminance and chromaticity can be used as the luminance and chromaticity measuring device 30. Note that a detailed description of the luminance and chromaticity measuring device 30 will be omitted here.

[0036] 3A and 3B, the processing executed by the control device 10 will be described. Here, an example of controlling an image of the B primary color will be described. However, the control device 10 can also execute similar processing for the R primary color and the G primary color.

[0037] The arithmetic circuit 11 selects one projection device from the first and second projection devices 20 (S001).

[0038] The arithmetic circuit 11 transmits a control signal to the projection device 20 selected in step S001 to project an image in the B primary color (S002).

[0039] The arithmetic circuit 11 acquires from the luminance and chromaticity measuring device 30 the measurement results of luminance and chromaticity when the projection device 20 projects the image of the B primary color in step S002 (S003).

[0040] The arithmetic circuit 11 returns to step S001 and repeats the processes of steps S001 to S003 until it has acquired the measurement results of the luminance and chromaticity of all the projection devices 20 (YES in S004).

[0041] The arithmetic circuit 11 selects the minimum luminance value, which is the smallest value, from the luminance values ​​of the projection devices 20 acquired in step S003 (S005).

[0042] The arithmetic circuit 11 generates an xy chromaticity diagram showing the color gamut of each projection device 20 acquired in step S002. The arithmetic circuit 11 also extracts chromaticity points of the two B primary colors (B primary color points) from the generated xy chromaticity diagram (S006).

[0043] The arithmetic circuit 11 calculates a B primary color point common to all the projection devices 20 from the color gamuts of each projection device 20 acquired in step S002 (S007). Fig. 4 shows an enlarged view of a portion of the B primary color point on the xy chromaticity diagram. Fig. 4 shows, in the enlarged view of the color gamut shown in Fig. 1B, the relationship between the B primary color point P1b(xb1, yb1) (first xy chromaticity point to be adjusted) of the first projection device 20A, the B primary color point P2b(xb2, yb2) (second xy chromaticity point to be adjusted) of the second projection device 20B, and the B primary color point Pb(xb, yb) (common xy chromaticity point) common to all the projection devices 20.

[0044] Here, the x and y coordinates of the common B primary color point can be calculated by the formulas (1.1) and (1.2), respectively. xb=(B2-B1) / (A1-A2) (1.1) yb=(A1×B2-A2×B1) / (A1-A2) (1.2) However, A1=(yg1-yb1) / (xg1-xb1) (2.1) A2=(yr2-yb2) / (xr2-xb2) (2.2) B2=yb1-((yg1-yb1) / (xg1-xb1))×xb1 (2.3) B2=yb2-((yr2-yb2) / (xr2-xb2))×xb2 (2.4) Note that, The chromaticity point of the R primary color (R primary color point) of the first projection device 20A is (xr1, yr1), the chromaticity point of the G primary color (G primary color point) is (xg1, yg1), and the R primary color point of the second projection device 20B is (xr2, yr2), and the G primary color point is (xg2, yg2).

[0045] The arithmetic circuit 11 displays an operation screen including a reception section used for adjusting the color gamut on the output device 13 (S008).

[0046] The arithmetic circuit 11 receives the rate of change for adjusting the color gamut via the operation screen displayed in step S008 (S009).

[0047] The arithmetic circuit 11 selects one of the first and second projection devices 20 (S010).

[0048] The arithmetic circuit 11 uses the rate of change received in step S009 to calculate the target chromaticity point of the projection device 20 selected in step S010 (S011).

[0049] Furthermore, the arithmetic circuit 11 transmits the minimum luminance value selected in step S005 and the target chromaticity point calculated in step S011 to the projection device 20 selected in step S010 (S012).

[0050] The arithmetic circuit 11 repeats the processes of steps S010 to S012 until it has transmitted the minimum luminance value and the target chromaticity point to all of the projection devices 20 (YES in S013).

[0051] FIG. 5A shows an example of an operation screen 130A displayed on the output device 13 in step S008. The operation screen 130A includes a receiving section 131A. The user can slide the receiving section 131A left or right via the input device 12. The arithmetic circuit 11 receives the amount of change in chromaticity according to the position of the receiving section 131A. In the example of FIG. 5A, the position indicated by the receiving section 131A corresponds to the rate of change. The arithmetic circuit 11 calculates the amount of change based on the rate of change indicated by the position of the receiving section 131A.

[0052] Specifically, for example, when the receiving unit 131A is slid to the left and moved to 0.0, the change rate is 0.0. When the change rate is 0.0, the arithmetic circuit 11 does not correct the chromaticity of each projection device 20. When the receiving unit 131A is slid to the right and moved to 1.0, the change rate is 1.0. When the change rate is 1.0, the arithmetic circuit 11 calculates the amount of change to correct the chromaticity of each projection device 20 to the common B primary color point Pb(xb, yb). When the receiving unit 131A is moved between 0.0 and 1.0, the change rate is 0.5. When the change rate is 0.5, the arithmetic circuit 11 calculates the amount of change to correct the chromaticity of each projection device 20 to an intermediate value between the common B primary color point Pb(xb, yb) and each of the current B primary color points P1b(xb1, yb1) and P2b(xb2, yb2).

[0053] In FIG. 4 , the target chromaticity point between the common B primary color point Pb(xb, yb) and the current B primary color point P1b(xb1, yb1) is defined as P1bt(xbt1, ybt1) (first target xy chromaticity point). The target chromaticity point between the common B primary color point Pb(xb, yb) and the current B primary color point P2b(xb2, yb2) is defined as P2bt(xbt2, ybt2) (second target xy chromaticity point). In this case, the coordinates indicating the target chromaticity point of the first projection device 20A can be calculated using equations (3.1) and (3.2), respectively. The coordinates indicating the target chromaticity point of the second projection device 20B can be calculated using equations (3.3) and (3.4), respectively. Here, rbt is the rate of change received via the receiving unit 131A. xbt1 = (xb - xb1) x rbt + xb1 (3.1) ybt1 = (yb - yb1) x rbt + yb1 (3.2) xbt2 = (xb - xb1) x rbt + xb1 (3.3) ybt2 = (yb - yb1) x rbt + yb1 (3.4) Here, rbt is the rate of change received by the receiving unit 131A.

[0054] FIG. 5B shows another example of an operation screen 130B. The operation screen 130B shown in FIG. 5B includes a receiving section 131B and a setting button 132B. The user inputs a value between 0.0 and 1.0 into the receiving section 131B via the input device 12 and operates the setting button 132B. The arithmetic circuit 11 receives the amount of change in chromaticity according to the value input into the receiving section 131B. In the example of FIG. 5B, the position indicated by the receiving section 131B corresponds to the rate of change. The arithmetic circuit 11 calculates the amount of change based on the value input into the receiving section 131B.

[0055] Specifically, for example, when a change rate of 0.0 is input to the receiving unit 131B, the arithmetic circuit 11 does not correct the chromaticity of each projection device 20. On the other hand, when a change rate of 1.0 is input to the receiving unit 131B, the arithmetic circuit 11 calculates a change amount for correcting the chromaticity of each projection device 20 to the common B primary color point Pb(xb,yb). When a change rate of 0.5 is input to the receiving unit 131B, the arithmetic circuit 11 calculates a change amount for correcting the chromaticity of each projection device 20 to an intermediate value between the common B primary color point Pb(xb,yb) and each current B primary color point P1b(xb1,yb1) or P2b(xb2,yb2). The method for calculating the target chromaticity point is the same as the method described using equations (3.1) to (3.4).

[0056] In this way, the display system 1 can adjust the RGB primary color points of each projection device 20 according to the received change rate. This allows a sense of uniformity in the color gamut when combining images projected from multiple projection devices 20 and displaying them as a single video content.

[0057] Measurement values ​​obtained by the luminance and chromaticity measuring device 30 may deviate from the human visual impression. The luminance and chromaticity measuring device 30 quantifies luminance and / or chromaticity using color-matching functions that model the characteristics of human vision. However, for reasons such as these color-matching functions not matching the spectral sensitivity of the human eye and the fact that the spectral sensitivity of the human eye varies greatly from person to person, making it difficult to quantify color using a single color-matching function, even if the chromaticities of multiple projection devices 20 are matched to a common B primary color point Pb(xb, yb), they may not appear to match to the human eye. This phenomenon can be mitigated by appropriately setting the rate of change and calculating and individually adjusting P1bt(xbt1, ybt1) (first target xy chromaticity point) and P2bt(xbt2, ybt2) (second target xy chromaticity point).

[0058] Furthermore, if the B primary color points of each projection device 20 are aligned with a common B primary color point, the B primary color points will shift inward on the xy chromaticity diagram, reducing the saturation of blue in each projection device 20 and causing the color to lose its vividness. Some users of the display system 1 may wish to maintain the saturation of blue even if it means leaving some color differences between the multiple projection devices 20. For this purpose as well, by appropriately setting the rate of change, adjustment can be made to achieve a good balance between achieving a sense of color unity and maintaining saturation.

[0059] When setting the rate of change for these purposes, rather than setting a slight change that is not noticeable to the human eye, i.e., a value close to 1.0 as the rate of change in the above embodiment, better results may be obtained by setting the rate of change so that the target xy chromaticity point moves away from the common B primary color point Pb(xb, yb), such as 0.8 to 0.1, depending on the projection device and viewing environment.

[0060] <Modification 1> In the example shown in Fig. 1A, the display system 1 has been described as using two projection devices 20. However, the display system may include three or more projection devices. Fig. 6 shows a display system 1A according to Modification 1. The display system 1A includes three projection devices 20. Note that the configuration of each of the devices 10 to 30 is the same as that of the devices described above, and therefore description thereof will be omitted.

[0061] Adjustment of the B primary color of the color gamut of each projection device 20 when there are three or more projection devices 20 will be described with reference to Fig. 7. Fig. 7 includes B primary color points P1b (xb1, yb1), P2b (xb2, yb2), and P3b (xb3, yb3) of each of the projection devices 20A to 20C when three projection devices 20A to 20C are included, as shown in Fig. 6.

[0062] FIG. 8 shows a flowchart illustrating the processing in the arithmetic circuit 11 when the display system includes three or more projection devices 20. In the flowchart shown in FIG. 8, steps that differ from those described above using the flowchart shown in FIG. 3A are underlined. Furthermore, the steps described using the flowchart shown in FIG. 3B are the same, so illustrations are omitted and reference is made to FIG. 3B. Specifically, the arithmetic circuit 11 executes step S106 instead of step S006. In step S106, the B primary color point located at the top left and the B primary color point located at the bottom right on the xy chromaticity diagram are extracted.

[0063] 7, in step S106, the B primary color point P2b (xb2, yb2) of the second projector 20B is extracted as the top left B primary color point, and the B primary color point P1b (xb1, yb1) of the first projector 20A is extracted as the bottom right B primary color point.

[0064] In the following step S107, the B primary color points of the common color gamut are calculated using the color gamuts of the two B primary color points extracted in step S106. The calculation of the B primary color points of the common color gamut uses the formulas (1.1) and (1.2) described above in the processing of step S007.

[0065] 3A and 3B, and therefore description thereof will be omitted. For example, when adjusting the color gamut of the third projection device 20C, a change amount for correcting the target chromaticity point P3bt(xbt3, ybt3) between the B-primary color point Pb(xb, yb) of the common color gamut extracted in step S106 and the current B-primary color point P3b(xb3, yb3) is calculated. The calculation of the target chromaticity point P3bt(xbt3, ybt3) uses equations (3.1) to (3.4) described above in the processing of step S011.

[0066] In this way, in a display system 1A including three or more projection devices 20, the arithmetic circuit 11 determines a common B-primary color point Pb based on the B-primary color points of two of the projection devices 20. At this time, the arithmetic circuit 11 selects two B-primary color points with the largest difference. Furthermore, for the B-primary color points of the other projection devices 20, the arithmetic circuit 11 uses the common B-primary color point Pb determined using the B-primary color points of the two projection devices 20. This allows the arithmetic circuit 11 to adjust the color gamut of each projection device 20 so that it has a consistent appearance.

[0067] <Modification 2> In the example shown in FIG. 1A, the display system 1 includes the luminance and chromaticity measuring device 30. However, the display system can measure the luminance and chromaticity using other techniques. FIG. 9 shows a display system 1B according to Modification 2. The display system 1B shown in FIG. 9 includes an imaging device 30B instead of the luminance and chromaticity measuring device 30. In FIG. 9, the range in which an image is projected by the projection device 20 is indicated by a dashed line. Also, in FIG. 9, the range in which an image is captured by the imaging device 30B is indicated by a dotted line. The configurations of the control device 10 and the projection device 20 are the same as those of the devices described above, and therefore description thereof will be omitted.

[0068] The arithmetic circuit 11 of the control device 10 according to the second modification generates, from the image captured by the image capturing device 30B, a chromaticity diagram of the image projected by each projection device 20. For example, an example will be described in which the image captured by the image capturing device 30B is an sRGB image.

[0069] 10 is a flowchart illustrating the processing of the arithmetic circuit 11 of the control device 10B of the display system 1B. In the flowchart shown in FIG. 10, in step S103, a captured image of the video projected in accordance with the control signal transmitted in step S002 is acquired from the image capturing device 30B.

[0070] Subsequently, in step S104, the arithmetic circuit 11 generates an xy chromaticity diagram from the captured image acquired in step S103. Specifically, the arithmetic circuit 11 converts the captured image, which is an sRGB image, into an XYZ image using equation (4). however, In the formula (4), X represents R, Y represents G, and Z represents B.

[0071] The arithmetic circuit 11 also converts the XYZ image into Yxy values ​​using equations (5.1) to (5.3). Y = Y (5.1) x = X / (X + Y + Z) (5.2) y = Y / (X + Y + Z) (5.3) Chromaticity coordinates are represented by x obtained from equation (5.2) and y obtained from equation (5.3). The arithmetic circuit 11 generates an xy chromaticity diagram from the chromaticity coordinates thus obtained.

[0072] In this way, in the display system 1B including the image capturing device 30B instead of the luminance and chromaticity measuring device 30, the arithmetic circuit 11 calculates the luminance and chromaticity from the captured image, thereby enabling the arithmetic circuit 11 to adjust the color gamut of each projection device 20 so as to have a uniform appearance.

[0073] As with the case where the luminance and chromaticity measurement device 30 described above is used, the measured values ​​obtained by the image capture device 30B may also deviate from the human visual impression. The ideal imaging characteristics of an sRGB image captured by the image capture device 30B are expressed by the simple matrix operation of Equation (4), which has a linear transformation relationship with the color matching function for quantifying the XYZ stimulus values. Therefore, the phenomenon that occurs when the luminance and chromaticity measurement device 30 is used, in which the chromaticities of multiple projection devices 20 do not appear to match to the human eye even when they are aligned to a common B primary color point Pb(xb, yb), also occurs when the image capture device 30B is used. This phenomenon can be mitigated, as with the case where the luminance and chromaticity measurement device 30 is used, by appropriately setting the rate of change.

[0074] Furthermore, when the primary color points of each projection device 20 are aligned with a common B primary color point, the saturation of blue of each projection device 20 decreases, and the vividness of the color is lost. This occurs whether the image capture device 30B is used or the luminance and chromaticity measurement device 30 is used. Therefore, by appropriately setting the rate of change, it is possible to perform adjustments that balance the sense of unity of color and the maintenance of saturation.

[0075] Although the explanation has been given using sRGB images, the same applies when other image formats such as Adobe RGB are used.

[0076] Although the example in which the display system 1 includes the luminance and chromaticity measuring device 30 and the example in which the image capturing device 30B is included has been described, the configuration of the display system 1 is not limited to this, and the Yxy values ​​measured in advance by the luminance and chromaticity measuring device, the RGB values ​​of an image captured by a camera, or the converted Yxy values ​​may be stored in each projection device 20 and read out and used during adjustment. Alternatively, the Yxy values ​​measured in advance may be stored in a server, and the arithmetic circuit 11 may obtain them via the cloud using a communication means.

[0077] <Modification 3> In the example described using FIG. 1B , the color gamuts of multiple projection devices 20A and 20B partially overlap, and each primary color point is outside the color gamut of the other projection device. In contrast, FIG. 11 shows an example of a difference in the size of the color gamut resulting from different types of light sources provided in multiple projection devices 20. As shown in FIG. 11 , the display system according to Modification 3 is an example in which the color gamut of the first projection device 20A is included in the color gamut of the second projection device 20B. Therefore, in the display system according to Modification 3, the B primary color point P1b of the first projection device 20A is also included in the color gamut of the second projection device 20B.

[0078] The configurations of the display system, control device, and projection device according to Modification 3 are the same as those described above with reference to FIGS. 2A to 2C, and therefore will be described with reference to FIGS. 2A to 2C.

[0079] <<Processing in Control Device>> The processing executed by the control device 10 will be described using the flowcharts shown in Figures 12A and 12B. Similar to the example described using Figures 3A and 3B, an example of controlling an image of the B primary color will be described below. However, the control device 10 can also execute similar processing for the R primary color and the G primary color. In the flowcharts shown in Figures 12A and 12B, reference symbols for processing that differ from those in Figures 3A or 3B are underlined. The same symbols are used for the same processing, and descriptions thereof will be omitted or simplified.

[0080] When the arithmetic circuit 11 acquires the measurement results of the luminance and chromaticity of all the projection devices 20 (YES in S004), it selects the minimum luminance value, which is the lowest value, from the luminance values ​​of each projection device 20 acquired in step S003 (S005).

[0081] The arithmetic circuit 11 generates an xy chromaticity diagram showing the color gamut of each projection device 20 acquired in step S002. The arithmetic circuit 11 also extracts chromaticity points of the two B primary colors (B primary color points) from the generated xy chromaticity diagram (S006).

[0082] The arithmetic circuit 11 determines a B primary color point common to each of the projection devices 20 from the color gamuts of each projection device 20 acquired in step S002 (S207). Figure 13 shows, in an enlarged view of the color gamut shown in Figure 11, the relationship between the B primary color point P1b (xb1, yb1) (first xy chromaticity point to be adjusted) of the first projection device 20A, the B primary color point P2b (xb2, yb2) (second xy chromaticity point to be adjusted) of the second projection device 20B, and the B primary color point Pb (xb, yb) (common xy chromaticity point) common to each projection device 20. In the example according to Modification 3, the color gamut of the first projection device 20A is included in the color gamut of the second projection device 20B, and therefore, as shown in Figure 13, the B primary color point P1b of the first projection device 20A and the B primary color point Pb common to each projection device 20 are the same. Therefore, the arithmetic circuit 11 sets the B primary color point Pb of the first projection device 20A as the B primary color point Pb common to all the projection devices 20.

[0083] The arithmetic circuit 11 displays an operation screen including a receiving section used for adjusting the color gamut on the output device 13 (S208). FIG. 14 shows an example of the operation screen 130C. Compared to the example described above with reference to FIG. 5B, the example of the operation screen shown in FIG. 14 allows input of two candidate change rates used for adjusting the color gamut. Specifically, the operation screen 130C shown in FIG. 14 includes a first receiving section 131C, a second receiving section 132C, and a setting button 133C. The user can input a candidate first change rate into the first receiving section 131C via the input device 12. The user can also input a candidate second change rate into the second receiving section 132C via the input device 12.

[0084] The arithmetic circuit 11 receives two candidate change rates for adjusting the color gamut via the operation screen displayed in step S208 (S209).

[0085] The arithmetic circuit 11 selects one of the first and second projection devices 20 (S210).

[0086] Using the two change rate candidates accepted in step S209, the arithmetic circuit 11 calculates first and second target chromaticity point candidates for the projection device 20 selected in step S210 (S211). If the first projection device 20A is selected, the arithmetic circuit 11 uses the first change rate candidate to calculate the first target chromaticity point candidate P11bt'(xbt11', ybt11'), as shown in FIG. 15 . Also, the arithmetic circuit 11 uses the second change rate candidate to calculate the second target chromaticity point candidate P21bt'(xbt21', ybt21'). If the second projection device 20B is selected, the arithmetic circuit 11 uses the second change rate candidate to calculate the first target chromaticity point candidate P12bt'(xbt12', ybt12'), as shown in FIG. Furthermore, the arithmetic circuit 11 uses the second change rate candidate to determine the second target chromaticity point candidate P22bt'(xbt22', ybt22'). Note that the chromaticity point when the change rate is "1" can be set to a position where a value exceeding 1 is not input, taking into account the color gamut variation range of the projection device 20 actually used. Alternatively, the chromaticity point can be arbitrarily determined, such as by setting it to a common G primary color point and a common R primary color point. Therefore, the change rate does not necessarily have to be a value between 0 and 1, as in the case described above with reference to FIG. 5B.

[0087] Furthermore, the arithmetic circuit 11 transmits the minimum luminance value selected in step S205 and the two target chromaticity points calculated in step S211 to the projection device 20 selected in step S010 (S212).

[0088] The arithmetic circuit 11 repeats the processes of steps S010 to S212 until it has transmitted the minimum luminance value and two target chromaticity point candidates to all of the projection devices 20 (S213).

[0089] After transmitting the minimum luminance value and the two target chromaticity point candidates to all projection devices 20 (YES in S213), the arithmetic circuit 11 causes each projection device 20 to project a first image candidate and a second image candidate (S214). Here, the first image candidate Im11 projected by the first projection device 20A is an image representing the first target chromaticity point candidate P11bt'. The first image candidate Im12 projected by the second projection device 20B is an image representing the first target chromaticity point candidate P21bt'. The second image candidate Im21 projected by the first projection device 20A is an image representing the first target chromaticity point candidate P21bt'. The second image candidate Im22 projected by the second projection device 20B is an image representing the first target chromaticity point candidate P22bt'. The first image candidates Im11 and Im21 and the second image candidates Im21 and Im22 may be displayed separately at different times, for example.

[0090] For example, the arithmetic circuit 11 may first cause each of the projection devices 20A and 20B to display first image candidates Im11 and Im21, respectively, as shown in FIG. 16A . Subsequently, the arithmetic circuit 11 may cause each of the projection devices 20A and 20B to display second image candidates Im12 and Im22, respectively, as shown in FIG. 16B . For example, the arithmetic circuit 11 may switch the display between the first image candidates Im11 and Im21 and the second image candidates Im21 and Im22 in accordance with a switching signal received from a user via the connected input device 12. Here, the first image candidates Im11 and Im21 and the second image candidates Im21 and Im22 may include information indicating whether the image is the first candidate or the second candidate. In the example shown in FIG. 16A , the first image candidate Im11 includes the number “1” indicating that it is the first candidate. In the example shown in FIG. 16B, the second image candidate Im21 includes the number "2" indicating that it is the second candidate.

[0091] For example, the arithmetic circuit 11 may simultaneously display first image candidates Im11 and Im21 and second image candidates Im21 and Im22, as shown in Fig. 17. In the example shown in Fig. 17, the first projection device 20A projects an image Im31 to be projected that includes both the first image candidate Im11 and the second image candidate Im21. At the same time, the second projection device 20B projects an image Im32 to be projected that includes both the first image candidate Im12 and the second image candidate Im22.

[0092] As described above, in the display system 1 according to the third modification, when the first B-primary color point P1b is within the color gamut of the second projection device 20B, the display state of each projection device can be controlled by using the first B-primary color point P1b as the common B-primary color point Pb. Furthermore, the target chromaticity point determined from the candidate target chromaticity points is located at a distance equal to or greater than the size of the MacAdam ellipse, which is the color discrimination range where colors are difficult for the human eye to distinguish, from the primary color points of each projection device 20 or the common B-primary color point. Specifically, when the primary color points of each projection device 20 or the common B-primary color point is set as the center of the MacAdam ellipse, the determined target chromaticity point is set to be outside the MacAdam ellipse. This allows the image to be adjusted so that the changes are noticeable to the human eye.

[0093] <Modification 4> The display system 1 according to the above-described modification 3 has been described as an example in which the color gamut of the first projection device 20A is within the color gamut of the second projection device 20B, and the second target chromaticity point is set within the color gamut of the first projection device 20A. In contrast, the display system according to modification 4 is an example in which when the color gamut of the first projection device 20A is included in the color gamut of the second projection device 20B, the second target chromaticity point is included outside the color gamut of the first projection device 20A.

[0094] The configurations of the display system, control device, and projection device according to Modification 4 are the same as those described above with reference to Figures 2A to 2C, and therefore will be described with reference to Figures 2A to 2C. In addition, the control device 10 according to Modification 4 executes the processing described with reference to Figures 16A and 16B, and therefore will be described with reference to Figures 16A and 16B.

[0095] In the display system 1 according to Modification 4, as shown in Fig. 18, the arithmetic circuit 11 can set a first target chromaticity point P1bt between points P1br and P1bg. The arithmetic circuit 11 can also set a second target chromaticity point P2bt between points P2br and P2bg. Note that points P1br, P1bg, P2br, and P2bg are determined by the change rates received in step S109 described above with reference to Fig. 16A. Note that the example shown in Fig. 18 shows a range in which the target chromaticity point is set for one change rate.

[0096] Therefore, the arithmetic circuit 11 can set the target chromaticity point within the range of the color gamut of the target projection device 20. FIG. 19 shows an example of target chromaticity points set when the range for setting the target chromaticity points is set as shown in FIG. 18. Specifically, FIG. 19 shows an example in which point P1br is set as the first target chromaticity point P1bt and point P2bg is set as the second target chromaticity point P2bt. Note that while FIG. 19 shows the second target chromaticity point P2bt at the same position as P2bg, it can be set at any position between P2br and P2bg. Furthermore, while FIG. 19 shows the first target chromaticity point P1bt at the same position as P1br, it can be set at any position between P1br and P1bg.

[0097] <Other Modifications> The display system 1 described above with reference to FIG. 2A and the display system 1A described above with reference to FIG. 6 have been described as examples including a luminance and chromaticity measurement device 30. Furthermore, the display system 1B described above with reference to FIG. 9 has been described as an example including an imaging device 30B. In these display systems 1, 1A, and 1B described above, luminance and chromaticity can be measured using the luminance and chromaticity measurement device 30 or the imaging device 30B. However, the display system does not necessarily have to include the luminance and chromaticity measurement device 30 or the imaging device 30B. When the display system does not include the luminance and chromaticity measurement device 30 or the imaging device 30B, the storage device 15 of the control device 10 stores the measurement results of the luminance and chromaticity of each projection device 20 that have been measured in advance. The control device 10 can execute processing using the measurement results of the luminance and chromaticity stored in the storage device 15.

[0098] In the examples of operation screens 130A and 130B described in the above-described embodiment using FIGS. 5A and 5B, one change rate is input. In the example where one change rate is input, one target chromaticity point can be determined based on the input change rate. Furthermore, in the example of operation screen 130C described in the above-described modification example 3 using FIG. 14, two candidate change rates are input. In the example where two candidate change rates are input, two target chromaticity point candidates are determined, and the user is prompted to select which one to select as the target chromaticity point. The method of inputting multiple candidate change rates and determining a target chromaticity point from the multiple candidate target chromaticity points, as described in modification example 3, may also be applied to the embodiment. Furthermore, the method of inputting one change rate and determining a target chromaticity point described in the embodiment may also be applied to modification example 3.

[0099] Overview of Embodiments (1) A control method disclosed herein is a control method for controlling each display device using a control device in a display system that displays one image using first and second display devices, the control device comprising: an arithmetic circuit of the control device that acquires color gamut information of each display device; extracts an xy chromaticity point of at least one vertex among the RGB vertices in the color gamut of the first display device as a first xy chromaticity point to be adjusted; extracts an xy chromaticity point of at least one vertex among the RGB vertices in the color gamut of the second display device as a second xy chromaticity point to be adjusted; calculates a common xy chromaticity point that is within a common range of the color gamuts of the first and second display devices; displays an image of the color gamut adjusted based on the first xy chromaticity point to be adjusted and the common xy chromaticity point on the first display device; and displays an image of the color gamut adjusted based on the second xy chromaticity point to be adjusted and the common xy chromaticity point on the second display device.

[0100] This allows the chromaticity of each display device to be adjusted in a system that combines images displayed by multiple display devices into a single image. At this time, the chromaticity of each display device can be adjusted to create a sense of unity. Furthermore, adjustment can be performed with a good balance between creating a sense of unity in color and maintaining saturation.

[0101] (2) The control method of (1) above may further include: calculating, by the arithmetic circuit, any xy chromaticity point on the xy chromaticity diagram that is located between the first and second adjustment-target xy chromaticity points and the common xy chromaticity point, as a first target xy chromaticity point and a second target xy chromaticity point, respectively; adjusting the vertices on the xy chromaticity diagram of an image to be displayed on each of the display devices so that they coincide with the first and second target xy chromaticity points; displaying, on the first display device, an image of the color gamut adjusted at the first target xy chromaticity point; and displaying, on the second display device, an image of the color gamut adjusted at the second target xy chromaticity point.

[0102] This allows the chromaticity of each display device to be adjusted in a system that combines images displayed by multiple display devices into a single image. At this time, the chromaticity of each display device can be adjusted to create a sense of unity. Furthermore, adjustment can be performed with a good balance between creating a sense of unity in color and maintaining saturation.

[0103] (3) The control method of (1) above may include: calculating, by the arithmetic circuit, an arbitrary xy chromaticity point on an xy chromaticity diagram, which is different from the common xy chromaticity point, as a first target xy chromaticity point and a second target xy chromaticity point, for each of the first and second xy chromaticity points to be adjusted; adjusting the vertices on the xy chromaticity diagram of an image to be displayed on each of the display devices so that they become the first and second target xy chromaticity points; displaying, on the first display device, an image having a color gamut adjusted based on the first target xy chromaticity point; displaying, on the second display device, an image having a color gamut adjusted based on the second target xy chromaticity point; the first target xy chromaticity point being within the color gamut of the first display device; and the second target xy chromaticity point being within the color gamut of the second display device.

[0104] (4) In the control method of (3) above, the first and second target xy chromaticity points may be positioned within a common range of the color gamuts of the first and second display devices by the arithmetic circuit.

[0105] This allows the chromaticity of each display device to be adjusted in a system that combines images displayed by multiple display devices into a single image. At this time, the chromaticity of each display device can be adjusted to create a sense of unity. Furthermore, adjustment can be performed with a good balance between creating a sense of unity in color and maintaining saturation.

[0106] (5) The control methods of (3) and (4) above may include, by the arithmetic circuit, calculating first candidates for the first target xy chromaticity point and the second target xy chromaticity point, and second candidates for the first target xy chromaticity point and the second target xy chromaticity point, adjusting the color gamut of the first display device based on the first candidates and displaying a first image candidate when the second display device has been adjusted based on the first candidates, adjusting the color gamut of the first display device based on the second candidates and displaying a second image candidate when the second display device has been adjusted based on the second candidates, accepting a selection of whether to adopt the first image candidate or the second image candidate, and controlling the first and second display devices in accordance with the accepted selection.

[0107] This makes it easier for users to adjust the color gamut of the display device to suit their preferences.

[0108] (6) In the control methods (3) to (5) above, the arithmetic circuit may control the first and second display devices to display the first image candidate and the second image candidate at different times.

[0109] This makes it easier for users to adjust the color gamut of the display device to suit their preferences.

[0110] (7) In the control methods (3) to (5) above, the arithmetic circuit may control the first and second display devices to simultaneously display the first image candidate and the second image candidate.

[0111] This allows the user to easily adjust the threshold of the display device to suit their preferences.

[0112] (8) In the control methods of (2) to (7) above, the arithmetic circuit may be connected to a display, and the arithmetic circuit may cause the display to display an operation screen including a reception unit that allows a user to select a change rate for determining an arbitrary xy chromaticity point between the common xy chromaticity point and each of the first and second xy chromaticity points to be adjusted, and the xy chromaticity points changed according to the change rate received from the user via the reception unit may be determined as the first and second target xy chromaticity points.

[0113] This allows the color gamut of the display device to be adjusted to a color gamut preferred by the user. The rate of change can be appropriately set to improve the sense of uniformity of chromaticity when the measurement device that determined the color gamut value of the display device acquired by the arithmetic circuit differs from the user's visual characteristics. Furthermore, when the user wishes to maintain high saturation, the rate of change can be set to achieve a good balance between the sense of uniformity of color and saturation. (9) In the control methods of (1) to (8) above, the arithmetic circuit may perform adjustments to both the first and second display devices in response to a single input to the receiving unit.

[0114] This allows the chromaticity of each display device to be adjusted by a simple user operation.

[0115] (10) In the control methods (1) to (9) above, the arithmetic circuit may be connected to a measurement device that measures the chromaticity of the RGB primary color video signals displayed by each of the display devices, and the arithmetic circuit may cause each of the display devices to display the RGB primary color video signals, obtain chromaticity information of the RGB primary color video signals measured by the measurement device, and use the obtained chromaticity information to determine the color gamut of each of the display devices.

[0116] This allows adjustment to unify the color gamuts of the display devices using the current color gamuts of the display devices measured by the measurement device.

[0117] (11) In the control method of (10) above, the measurement device may be capable of measuring the luminance value together with the chromaticity of the video signal, and the arithmetic circuit may acquire the luminance values ​​of the video signals of the RGB primary colors measured by the measurement device, and adjust the luminance value of the video displayed on each of the display devices to be the lowest luminance value among the acquired luminance values.

[0118] This allows adjustments to be made so that the color gamuts of the display devices are consistent, as well as the brightness is consistent.

[0119] (12) In the control methods of (1) to (9) above, the arithmetic circuit may be connected to an image capturing device that captures an image of the RGB primary colors displayed by each of the display devices, and the arithmetic circuit may cause each of the display devices to display an image signal of the RGB primary colors, obtain a captured image of the image signal captured by the image capturing device, and use the obtained captured image to determine the color gamut of each of the display devices.

[0120] This allows the color gamut of each display device to be adjusted according to the current color gamut of each display device measured by the measurement device.

[0121] (13) The computer program of the present disclosure may cause a control device to execute the control method described in any one of (1) to (12).

[0122] This allows the chromaticity of each display device to be adjusted in a system in which images displayed by multiple display devices are synthesized into a single image, so that the chromaticity of each display device can be adjusted to have a uniform appearance.

[0123] (14) A control device according to the present disclosure may be a control device that controls each display device in a display system that displays one image using first and second display devices, the control device including an arithmetic circuit, which acquires information about the color gamut of each display device, extracts an xy chromaticity point of at least one of the RGB vertices in the color gamut of the first display device as a first xy chromaticity point to be adjusted, extracts an xy chromaticity point of at least one of the RGB vertices in the color gamut of the second display device as a second xy chromaticity point to be adjusted, calculates a common xy chromaticity point that is within a common range of the color gamuts of the first and second display devices, displays an image of the color gamut adjusted based on the first xy chromaticity point to be adjusted and the common xy chromaticity point on the first display device, and displays an image of the color gamut adjusted based on the second xy chromaticity point to be adjusted and the common xy chromaticity point on the second display device.

[0124] This allows for the chromaticity of each display device to be adjusted in a system that combines images displayed by multiple display devices into a single image. At this time, the color gamut of each display device can be adjusted to create a sense of unity. Furthermore, adjustments can be made that achieve a good balance between the sense of unity of color and the preservation of saturation.

[0125] (15) A display system according to the present disclosure includes first and second display devices and a control device that controls each of the display devices, and displays one image using each of the display devices, and an arithmetic circuit of the control device acquires color gamut information of each of the display devices, extracts an xy chromaticity point of at least one of the RGB vertices in the color gamut of the first display device as a first xy chromaticity point to be adjusted, extracts an xy chromaticity point of at least one of the RGB vertices in the color gamut of the second display device as a second xy chromaticity point to be adjusted, calculates a common xy chromaticity point that is within a common range of the color gamuts of the first and second display devices, displays an image of the color gamut adjusted based on the first xy chromaticity point to be adjusted and the common xy chromaticity point on the first display device, and displays an image of the color gamut adjusted based on the second xy chromaticity point to be adjusted and the common xy chromaticity point on the second display device.

[0126] This allows the color gamut of each display device to be adjusted in a system that combines images displayed by multiple display devices into a single image. At this time, the color gamut of each display device can be adjusted to create a sense of unity. Furthermore, adjustment can be performed with a good balance between the sense of unity of color and the maintenance of saturation.

[0127] The control method, the control device, the display system, and the computer program according to all claims of the present disclosure are realized by hardware resources, such as a processor, a memory, and cooperation with a computer program.

[0128] The control method, control device, display system, and computer program disclosed herein are useful for adjusting the color gamut of each projection device in a projection system that uses multiple projection devices to project images. Note that the control method, control device, display system, and computer program disclosed herein are also useful for adjusting the color gamut when multiple flat panel displays (liquid crystal displays, OLEDs) or multiple LED displays configured with LED arrays are used instead of each projection device in a projection system that uses multiple projection devices.

Claims

1. A control method for controlling each display device using a control device in a display system that displays one image using first and second display devices, the method comprising the steps of: acquiring color gamut information for each display device using an arithmetic circuit in the control device; extracting the xy chromaticity point of at least one vertex among the RGB vertices in the color gamut of the first display device as a first xy chromaticity point to be adjusted; extracting the xy chromaticity point of at least one vertex among the RGB vertices in the color gamut of the second display device as a second xy chromaticity point to be adjusted; calculating a common xy chromaticity point that is within a common range of the color gamuts of the first and second display devices; displaying an image of the color gamut adjusted based on the first xy chromaticity point to be adjusted and the common xy chromaticity point on the first display device; and displaying an image of the color gamut adjusted based on the second xy chromaticity point to be adjusted and the common xy chromaticity point on the second display device.

2. The control method according to claim 1, wherein the arithmetic circuit calculates any xy chromaticity point on the xy chromaticity diagram that is located between the first and second xy chromaticity points to be adjusted and the common xy chromaticity point as a first target xy chromaticity point and a second target xy chromaticity point, respectively; adjusts the vertices on the xy chromaticity diagram of the image to be displayed on each of the display devices so that they become the first and second target xy chromaticity points that have been set, respectively; displays the image of the color gamut adjusted at the first target xy chromaticity point on the first display device; and displays the image of the color gamut adjusted at the second target xy chromaticity point on the second display device.

3. The control method of claim 1, wherein the arithmetic circuit calculates, on an xy chromaticity diagram, arbitrary xy chromaticity points different from the common xy chromaticity point for each of the first and second xy chromaticity points to be adjusted, as first target xy chromaticity points and second target xy chromaticity points, respectively; adjusts the vertices on the xy chromaticity diagram of an image to be displayed on each of the display devices so that they coincide with the first and second target xy chromaticity points set, respectively; displays, on the first display device, an image with a color gamut adjusted based on the first target xy chromaticity points; displays, on the second display device, an image with a color gamut adjusted based on the second target xy chromaticity points; the first target xy chromaticity points are within the color gamut of the first display device; and the second target xy chromaticity points are within the color gamut of the second display device.

4. The control method according to claim 3, wherein the first and second target xy chromaticity points are positioned within a common range of the color gamuts of the first and second display devices by the arithmetic circuit.

5. A control method according to claim 2 or 3, wherein the arithmetic circuit calculates first candidates for the first target xy chromaticity point and the second target xy chromaticity point, and second candidates for the first target xy chromaticity point and the second target xy chromaticity point, adjusts the color gamut of the first display device based on the first candidates, and displays a first image candidate when the second display device is adjusted based on the first candidate, adjusts the color gamut of the first display device based on the second candidate, and displays a second image candidate when the second display device is adjusted based on the second candidate, accepts a selection of whether to adopt the first image candidate or the second image candidate, and controls the first and second display devices in accordance with the accepted selection.

6. The control method according to claim 5, wherein the arithmetic circuit controls the first and second display devices to display the first image candidate and the second image candidate at different times.

7. The control method according to claim 5, wherein the arithmetic circuit controls the first and second display devices to simultaneously display the first image candidate and the second image candidate.

8. The control method according to claim 2 or 3, wherein the arithmetic circuit is connected to a display, and the arithmetic circuit causes the display to display an operation screen including a reception unit that allows a user to select a change rate for determining an arbitrary xy chromaticity point between the common xy chromaticity point and each of the first and second xy chromaticity points to be adjusted, and determines the xy chromaticity point changed according to the change rate received from the user via the reception unit as the first and second target xy chromaticity points.

9. The control method according to claim 8, wherein the arithmetic circuit executes adjustments for both the first and second display devices in response to a single input to the reception unit.

10. A control method as described in claim 1, wherein the arithmetic circuit is connected to a measurement device that measures the chromaticity of the RGB primary color video signals displayed by each of the display devices, and the arithmetic circuit causes each of the display devices to display the RGB primary color video signals, obtains chromaticity information of the RGB primary color video signals measured by the measurement device, and calculates the color gamut of each of the display devices using the obtained chromaticity information.

11. The control method according to claim 10, wherein the measuring device is capable of measuring the luminance value together with the chromaticity of the video signal, and the arithmetic circuit acquires the luminance value of the video signal of the RGB primary colors measured by the measuring device, and adjusts the luminance value of the video displayed on each of the display devices so that it becomes the lowest luminance value among the acquired luminance values.

12. A control method as described in claim 1, wherein the arithmetic circuit is connected to an imaging device that captures images of the RGB primary colors displayed by each of the display devices, and the arithmetic circuit causes each of the display devices to display an RGB primary color image signal, acquires a captured image of the image signal captured by the imaging device, and uses the acquired captured image to determine the color gamut of each of the display devices.

13. A computer program for causing a control device to execute the control method according to any one of claims 1 to 3.

14. A control device for controlling each display device in a display system that displays one image using first and second display devices, the control device comprising an arithmetic circuit, which acquires color gamut information of each display device, extracts the x and y chromaticity point of at least one vertex among the RGB vertices in the color gamut of the first display device as a first x and y chromaticity point to be adjusted, extracts the x and y chromaticity point of at least one vertex among the RGB vertices in the color gamut of the second display device as a second x and y chromaticity point to be adjusted, calculates a common x and y chromaticity point that is within a common range of the color gamuts of the first and second display devices, displays an image of the color gamut adjusted based on the first x and y chromaticity point to be adjusted and the common x and y chromaticity point on the first display device, and displays an image of the color gamut adjusted based on the second x and y chromaticity point to be adjusted and the common x and y chromaticity point on the second display device.

15. A display system comprising first and second display devices and a control device for controlling each of the display devices, and displaying one image using each of the display devices, wherein an arithmetic circuit of the control device acquires color gamut information of each of the display devices, extracts the xy chromaticity point of at least one vertex among the RGB vertices in the color gamut of the first display device as a first xy chromaticity point to be adjusted, extracts the xy chromaticity point of at least one vertex among the RGB vertices in the color gamut of the second display device as a second xy chromaticity point to be adjusted, calculates a common xy chromaticity point that is within a common range of the color gamuts of the first and second display devices, displays an image of the color gamut adjusted based on the first xy chromaticity point to be adjusted and the common xy chromaticity point on the first display device, and displays an image of the color gamut adjusted based on the second xy chromaticity point to be adjusted and the common xy chromaticity point on the second display device.

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