Video signal transmission verification system, display device, video signal transmission verification method, and video signal transmission verification program

Abstract

Provided is a verification system capable of eliminating an error caused in the process of transmission of a video signal to a display device without depending on the skill level of an operator.　Provided according to the present invention is a video signal transmission verification system comprising a display device, a first transmission path, an output device, and an analysis unit, wherein the display device has a first controller, the analysis unit compares comparison data acquired by the first controller with a read expected value expected as a value to be acquired by the first controller, the comparison data is data related to the pixel value of a first pixel and obtained from a first signal transmitted from the output device to the display device via the first transmission path, the first signal is a video signal representing a first image having a first region including the first pixel, and if a mismatch is found in the comparison result between the comparison data and the read expected value, the analysis unit presents, to the user of the display device, a solution corresponding to the type of the mismatch.

Description

Video signal transmission verification system, display device, video signal transmission verification method, and video signal transmission verification program

[0001] The present invention relates to a video signal transmission verification system and a display device, and also to a video signal transmission verification method and a verification program.

[0002] The video production industry, typified by film production, requires precise color reproduction and adjustment across a wide dynamic range. To meet these demanding image requirements, video output devices and display devices must also have high performance, and compatibility between these devices must also be verified. Mismatches between a video output device and the display device connected to it can result in images with unintended gradations (or colors) being displayed on the display device.

[0003] The following Patent Document 1 discloses a self-diagnosis system that can determine whether unintended degradation in image quality is due to incorrect settings on the receiving side or to a malfunction of the equipment. The following Patent Document 2 discloses a technology that displays the coordinate values ​​and gradation of a pixel at a specified position by superimposing them on an image projected on a screen.

[0004] US Patent Application Publication No. 2019 / 172383 US Patent Application Publication No. 2004 / 246276

[0005] In cases where, for example, the color gamut settings are inconsistent between the sender and receiver of the video signal, causing a color shift in the displayed image, identifying which of the various settings is inconsistent and adjusting it to the intended color tone has traditionally relied heavily on the experience and intuition of the operator.

[0006] According to the present invention, the following inventions are provided: [1] A verification system for video signal transmission, comprising: a display device, a first transmission path, an output device, and an analysis unit, wherein the display device has a first controller, and the analysis unit compares comparison data acquired by the first controller with an expected read value that is expected as a value acquired by the first controller, wherein the comparison data is data related to a pixel value of a first pixel obtained from a first signal sent from the output device to the display device via the first transmission path, and the first signal is a video signal representing a first image having a first area including the first pixel, and when the analysis unit finds an inconsistency in the comparison result between the comparison data and the expected read value, the analysis unit presents a solution according to the type of the inconsistency to a user of the display device. [2] The verification system according to [1], wherein the display device further comprises a video memory, the video memory temporarily holds the first signal, and the first controller, upon receiving a request from the output device, obtains a pixel value for at least the first pixel from the output of the video memory. [3] The verification system according to [1] or [2], wherein the output device has a second controller, and the first controller of the display device acquires the comparison data in response to a request from the second controller of the output device. [4] The verification system according to [3], wherein at least one of the output device and the display device further has a display panel, and the second controller of the output device displays the solution on the display panel. [5] The verification system according to [4], wherein the display device has the display panel, and displays the position coordinates and pixel value of the first pixel on the display panel. [6] The verification system according to any one of [1] to [5], wherein the analysis unit is part of the output device, and the first controller of the display device sends the comparison data as a second signal from the display device to the output device.[7] The verification system according to any one of [1] to [6], wherein the analysis unit determines that the read expected value and the comparison data match when a difference between pixel values ​​at common position coordinates is within a predetermined range in a comparison between the read expected value and the comparison data. [8] The verification system according to any one of [1] to [7], wherein the first controller acquires pixel values ​​of a plurality of pixels including the first pixel as the comparison data, the read expected value includes pixel values ​​of a plurality of pixels included in the first region, and the analysis unit, in determining whether or not there is a mismatch between the comparison data and the read expected value, compares the plurality of pixel values ​​acquired by the first controller with the plurality of pixel values ​​constituting the read expected value on a pixel-by-pixel basis. [9] The verification system according to any one of [1] to [7], wherein the first controller acquires pixel values ​​of a plurality of pixels including the first pixel as the comparison data, and the analyzer compares a value obtained by performing statistical processing on the plurality of pixel values ​​acquired by the first controller with the read expected value in determining whether or not there is a mismatch between the comparison data and the read expected value.

[10] The verification system according to any one of [1] to [9], wherein the first controller acquires pixel values ​​after conversion into RGB video signals.

[11] A verification system according to any one of [1] to

[10] , wherein the first image (1) further includes a second region whose pixel value differs by a predetermined value or more in the gradation direction compared to the first region, (2) includes four or more regions including the first region, each of which has a pixel value that differs by one in the gradation direction, or (3) further includes a third region and a fourth region in addition to the first region, and the first region, the third region, and the fourth region are three regions each composed of one different color from the three primary colors.

[12] A display device comprising a first controller and an analysis unit, wherein the analysis unit compares comparison data acquired by the first controller with an expected read value that is expected to be acquired by the first controller, wherein the comparison data is data related to a pixel value of a first pixel obtained from a first signal input to the display device via a first transmission path, and the first signal is a video signal representing a first image having a first area including the first pixel, and wherein, when the analysis unit finds an inconsistency in the comparison result between the comparison data and the expected read value, the analysis unit presents a solution to a user according to the type of inconsistency.

[13] A method for verifying video signal transmission, comprising: a step (a) of sending a first signal via a first transmission path to a display device having a first controller, the first signal being a video signal representing a first image having a first region including a first pixel; a step (b) of acquiring, by the first controller, data related to the pixel value of the first pixel obtained from the first signal sent to the display device via the first transmission path; and a step (c) of determining whether or not an inconsistency has occurred in the comparison result between the comparison data and a read expected value that is expected to be acquired by the first controller, and extracting a solution according to the type of the inconsistency.

[14] A program for verifying video signal transmission, comprising machine-readable instructions, which, when executed by one or more processors, causes the one or more processors to: send a first signal via a first transmission path to a display device having a first controller, wherein the first signal is a video signal representing a first image having a first area including a first pixel; cause the first controller to acquire, as comparison data, data related to a pixel value of the first pixel obtained from the first signal sent to the display device via the first transmission path; determine whether or not a mismatch occurs in a comparison result between the comparison data and a read-out expected value that is expected as a value acquired by the first controller; and extract a solution depending on the type of the mismatch.

[15] A computer-readable non-transitory recording medium having recorded thereon a computer program for causing a computer to execute the method according to

[13] .

[16] A verification system for video signal transmission, comprising: a display device having a video memory and a first controller; a first transmission path; an output device; and an analysis unit; wherein the video memory of the display device temporarily holds a first signal sent from the output device to the display device via the first transmission path, wherein the first signal is a video signal relating to image data including at least one area, and the at least one area includes a first area having a first pixel; upon receiving a request from the output device, the first controller of the display device obtains a pixel value relating to the first pixel from the output of the video memory as comparison data; and the analysis unit obtains at least the comparison data and the pixel value relating to the first pixel before the output device outputs the first signal to the first transmission path as original data; and verifies at least whether the comparison data is consistent with an expected read value expected from the original data; and if there is an inconsistency in the comparison between the comparison data and the expected read value, presents a solution according to the type of inconsistency to a user of the display device.

[0007] According to at least one of the embodiments of the present invention, it becomes possible to resolve errors that occur in the process of transmitting video signals to a display device in a manner that does not depend on the skill level of an operator.

[0008] 1 is a functional block diagram for explaining a verification system according to an embodiment of the present invention. FIG. 1 is a diagram showing an example of a test pattern prepared in advance in the memory 14 of the output device 100. FIG. 2 is a diagram showing another example of a test pattern prepared in advance in the memory 14 of the output device 100. FIG. 3 is a diagram showing yet another example of a test pattern prepared in advance in the memory 14 of the output device 100. FIG. 4 is a diagram showing yet another example of a test pattern prepared in advance in the memory 14 of the output device 100. FIG. 5 is a flowchart showing an outline of an exemplary verification method according to another embodiment of the present invention. FIG. 1 is a functional block diagram showing exemplary details of the output device 100. FIG. 2 is a functional block diagram showing exemplary details of the display device 200. FIG. 3 is a diagram showing an example of a solution presented to a user by the verification system 1 when a mismatch is found between a read expected value and comparison data. FIG. 4 is a diagram showing an example of comparison data obtained when the test pattern 42 shown in FIG. 3 is used. FIG. 5 is a diagram showing a first example of comparison data obtained when the test pattern 44 shown in FIG. 5 is used. FIG. 6 is a diagram showing a second example of comparison data obtained when the test pattern 44 shown in FIG. 5 is used. FIG. 6 is a diagram schematically showing an example in which pixel position coordinates and pixel values ​​are superimposed on a test pattern and displayed on a display panel 28. It is a functional block diagram showing a first modified example of the verification system of the present invention. It is a functional block diagram showing a second modified example of the verification system of the present invention. It is a functional block diagram showing a third modified example of the verification system of the present invention. It is a functional block diagram showing a fourth modified example of the verification system of the present invention.

[0009] In the video production industry, a variety of video devices are interconnected and used. Therefore, display devices (e.g., monitors) that display video signals in the form of images (referring to "still images" and "moving images"; the same applies below) are required to support a variety of video formats. In addition, as the quality required for video becomes increasingly sophisticated, the settings for both video output devices and display devices are becoming more complex.

[0010] If there is a mismatch in the settings between a video output device and a display device during signal exchange via a transmission path, the video cannot be displayed on the display device with the intended gradation and color. Furthermore, the transmission of video signals involves an operating system (OS), application software, cables, switchers, and other devices, and mismatches in settings and standards among these can sometimes prevent video content from being displayed with the intended gradation and color. In such cases, continuing work without noticing the mismatch in settings between devices can result in unnecessary rework.

[0011] Errors in the transmission of video signals over a transmission path typically appear as degradation in image quality in the form of deviations in hue or brightness, but it takes skill for an operator to notice such degradation. Furthermore, it is not easy for an operator with little skill to deduce the cause of such errors and find a solution.

[0012] The inventors discovered that some of these errors manifest as degradation of image quality depending on the type of inconsistency in settings between devices, and thus completed the present invention. A verification system according to an embodiment of the present invention determines, for example, whether a mismatch occurs between pixel values ​​sent from a video output device and actual pixel values ​​received via a transmission path and used for display on a display device. According to an embodiment of the present invention, if an unacceptable discrepancy occurs between these pixel values, for example, a solution according to the tendency of the discrepancy is presented to the operator, thereby enabling the operator, regardless of their level of proficiency, to identify the cause of the error in the exchange of video signals via the transmission path and quickly resolve the error.

[0013] The following describes embodiments of the present invention. The various features shown in the following embodiments can be combined with each other. Furthermore, each feature can be an independent invention.

[0014] 1. Overview of a verification system for video signal transmission Fig. 1 shows an overview of a verification system according to an embodiment of the present invention. The verification system 1 shown in Fig. 1 includes an output device 100, a display device 200, and a first transmission path 10. The first transmission path 10 is used for transmitting video signals between the output device 100 and the display device 200.

[0015] The output device 100 is an information processing device configured to be able to output prepared image data in the form of a video signal, and typically includes a processor and one or more memories. For example, a personal computer can be used as the output device 100. As will be understood from the following description, any device capable of outputting video can be used as the output device 100 without any particular restrictions.

[0016] The display device 200 is a device (e.g., a monitor) used to present video content. In the example shown in Fig. 1, the display device 200 includes a display panel 28 on which an image is displayed. A typical example of the display panel 28 is a liquid crystal display panel. The display panel 28 may also be a self-luminous device such as a micro LED display or an organic EL display.

[0017] 1 , the display device 200 further includes a first controller 21, a video memory 24, and a video signal processing unit 26. As will be described in detail later, in a typical embodiment of the present invention, the display device 200 receives a video signal as a first signal sent from the output device 100 via the first transmission path 10, and temporarily stores the first signal in the video memory 24. Here, the first signal is, for example, a digital video signal representing one frame of image. The first signal may also be a digital video signal representing several frames of image. In the following description, the first signal is assumed to be a digital video signal (for example, a YCbCr digital video signal).

[0018] The first controller 21 is composed of a processor such as a CPU, and is responsible for controlling each part of the display device 200. The video signal processing unit 26 reads out and decodes the first signal temporarily stored in the video memory 24 based on instructions from the first controller 21. The decoded data includes pixel value information for each pixel that constitutes the image represented by the first signal. The first controller 21 displays an image corresponding to the signal obtained by decoding on the display panel 28.

[0019] The first transmission path 10 of the verification system 1 is, for example, a transmission line connecting the output device 100 and the display device 200. Typical examples of the first transmission path 10 are various video cables such as an HDMI (registered trademark) cable, a DisplayPort (DP) cable, and an SDI cable. However, the term "transmission path" in this specification is not limited to a signal line with a physical entity. "Transmission" in this specification encompasses not only wired transmission but also wireless transmission.

[0020] Here, the verification system 1 has a second transmission path 20 in addition to a first transmission path 10. The second transmission path 20 is, for example, a control signal line. A typical example of the second transmission path 20 is a USB (Universal Serial Bus) cable. It is not essential that the verification system 1 has separate cables as the first transmission path 10 and the second transmission path 20. For example, if a DP cable is used as the first transmission path 10, a single DP cable can function as both the first transmission path 10 and the second transmission path 20.

[0021] In this example, the output device 100 has a second controller 12, and a second transmission path 20 connects the second controller 12 to a first controller 21 of the display device 200. The second controller 12 is configured by a CPU and the like, similar to the first controller 21 of the display device 200, and controls each part of the output device 100.

[0022] 1 , the output device 100 further includes a memory 14 and an image processing unit 16. As will be described in detail later, in a typical embodiment of the present invention, image data representing a first image having a first region including a first pixel is stored in advance in the memory 14. The image processing unit 16 encodes the data output from the memory 14 into a video signal based on the control of the second controller 12, for example, and sends the encoded data to the display device 200 via the first transmission path 10.

[0023] In this example, the output device 100 also has an analysis unit 30. The functions of the analysis unit 30 will be described later. The functions of the second controller 12, the image processing unit 16, and the analysis unit 30 can be realized by a processor such as a CPU or GPU included in the output device 100. The second controller 12, the image processing unit 16, and the analysis unit 30 may each be realized by a separate processor, or two or more of these functions may be realized by a single processor.

[0024] 2. Example of Verification Test Pattern As described above, in a typical embodiment of the present invention, image data representing a predetermined first image is pre-stored in the memory 14 of the output device 100. Here, the first image may be, for example, a test pattern including at least one color patch, or a collection of such test patterns. As will be described in detail later, the verification system 1 first sends a first signal from the output device 100 to the display device 200 via the first transmission path 10, and performs a comparison between data related to the pixel value of the first pixel actually acquired by the first controller 21 in the display device 200 and data expected to be read from the image data before transmission (hereinafter simply referred to as the “expected read value”). The above-mentioned analysis unit 30 determines whether or not an inconsistency occurs between these data in this comparison. If an inconsistency is found in the comparison results, the analysis unit 30 presents a solution to the user of the display device 200 according to the type of inconsistency. Details of test patterns that can be used to verify the transmission of a video signal via the first transmission path 10 are described below.

[0025] 2 shows an example of a test pattern prepared in advance in the memory 14 of the output device 100. The test pattern 41 shown in FIG. 2 includes a first color patch C1 as a first region. Here, the first color patch C1 is an achromatic patch, and the pixel value of each pixel constituting the first color patch C1 is, for example, 64. That is, when expressed in RGB values, it becomes (64, 64, 64). Note that in this specification, the term "color" is not limited to chromatic colors and may also be used to refer to achromatic colors.

[0026] Fig. 3 shows another example of a test pattern as a first image. The test pattern 42 shown in Fig. 3 further includes, in addition to a first color patch C1, a second color patch C2 as a second region and a third color patch C3 as a third region. In the example shown in Fig. 3, the first color patch C1, the second color patch C2, and the third color patch C3 are all achromatic patches.

[0027] The test pattern 42 includes one or more color patches whose pixel values ​​differ in the gradation direction from the first color patch C1 by at least a predetermined value. Here, the predetermined value is, for example, 2 or 3. In the example shown in FIG. 3 , the pixel value of the second color patch C2 is 512, and the pixel value of the third color patch C3 is 940. That is, the second color patch C2 and the third color patch C3 are represented by RGB values ​​of (512, 512, 512) and (940, 940, 940), respectively.

[0028] 3, the test pattern used to verify video signal transmission via the first transmission path 10 may include two or more areas (e.g., two or more color patches), each of which is expressed by a specific pixel value. As will be understood from the following description, the test pattern may have only one color patch, but if the test pattern includes two or more color patches, the verification of video signal transmission can be performed more effectively.

[0029] FIG. 4 shows yet another example of a test pattern. The test pattern 43 shown in FIG. 4 includes four color patches: a first color patch M1, a second color patch M2, a third color patch M3, and a fourth color patch M4. Here, the first color patch M1 to the fourth color patch M4 are all achromatic patches, and the pixel values ​​differ by one in the gradation direction. In the example shown in FIG. 4, the pixel values ​​of the first color patch M1, the second color patch M2, the third color patch M3, and the fourth color patch M4 are 510, 511, 512, and 513, respectively. These are expressed in RGB values ​​as (510, 510, 510), (511, 511, 511), (512, 512, 512), and (513, 513, 513), respectively.

[0030] FIG. 5 shows yet another example of a test pattern. The test pattern 44 shown in FIG. 5 includes three color patches: a first color patch R1, a second color patch G2, and a third color patch B3, each of which is a chromatic color. The first color patch R1, the second color patch G2, and the third color patch B3 are patches expressed using RGB values ​​of, for example, (512,0,0), (0,512,0), and (0,0,512), respectively. That is, here, the first color patch R1, the second color patch G2, and the third color patch B3 are patches expressed using the single colors red, green, and blue, respectively. In this way, the test pattern used to verify the first transmission path 10 may include three color patches, each consisting of one different color from the three primary colors.

[0031] 3. Signal Transmission Path Verification Method Next, details of an exemplary verification method using the above-described verification system 1 will be described. As illustrated in FIG. 6 , the verification method using the verification system 1 may generally include the steps of: sending a first signal to the display device 200 via the first transmission path 10; acquiring data related to a pixel value of a first pixel in a first image as comparison data using the first controller 21; and determining whether or not an inconsistency occurs in a comparison result between the comparison data and an expected read value that is expected as a value acquired by the first controller 21. Furthermore, in this embodiment, if it is determined that an inconsistency exists in the comparison result between the comparison data and the expected read value, the verification system 1 executes the step S4 of presenting a solution to the user according to the type of inconsistency between the expected read value and the comparison data.

[0032] First, a first image to be used for verifying video signal transmission is prepared. Here, the test pattern 42 shown in Fig. 3 is used as the first image. As will be clear from the following description, application of the test pattern 42 makes it possible to determine whether or not there is a mismatch in the range settings between the output device 100 and the display device 200.

[0033] The test pattern 42 as the first image may be stored in advance in the memory 14 of the output device 100. In the example described here, the test pattern 42 is digital data (e.g., an image file) representing one frame of image. As described above, the first color patch C1 of the test pattern 42 includes multiple pixels, each of which is represented by an RGB value of (64, 64, 64). Hereinafter, for convenience, one of the pixels included in the color patch in the test pattern (e.g., one of the pixels constituting the first color patch C1) may be referred to as the "first pixel."

[0034] (Step S1 of sending a first signal to a display device via a first transmission path) When verifying video signal transmission via the first transmission path 10, for example, the second controller 12 (see FIG. 1) of the output device 100 sends digital data of a test pattern 42 from the memory 14 to the image processing unit 16. The image processing unit 16 converts the image data relating to the test pattern 42, which has been read from the memory 14, into a video signal (first signal).

[0035] FIG. 7 shows an example of the detailed configuration of the output device 100. In the configuration illustrated in FIG. 7, the image processing unit 16 includes a color management unit 61, an encoder 63, and a range conversion unit 65. The color management unit 61 converts image data (expressed in RGB values) read from the memory 14 into image data in another color space as necessary. For example, if the image data read from the memory 14 is a signal expressed in the BT.709 color space and the first signal is intended to be output as a signal expressed in the BT.2020 color space, the color management unit 61 converts RGB values ​​in the BT.709 color space into RGB values ​​in the BT.2020 color space. If the color space of the image data stored in the memory 14 is already matched to the color space intended as the format of the output signal, conversion between color spaces by the color management unit 61 is unnecessary. An encoder 63 downstream of the color management unit 61 converts image data (image data relating to the test pattern 42 in this case) into a compressed video signal (a YCbCr digital video signal in this case). Depending on the transmission path used, the image data may remain as an uncompressed RGB digital signal. A range conversion unit 65 limits the digital values ​​representing the video signal to a predetermined range (e.g., a limited range) as necessary.

[0036] The output device 100 sends the first signal obtained by processing by the image processing unit 16 to the display device 200 via the first transmission path 10. In a typical embodiment of the present invention, the first controller 21 of the display device 200 stores the first signal sent from the output device 100 via the first transmission path 10 in the video memory 24.

[0037] 8 shows an example of the detailed configuration of the display device 200. In the configuration shown in FIG. 8, the display device 200 has a video signal processing unit 26 including a range extension unit 62, a decoder 64, and a correction processing unit 66, located downstream of the video memory 24. The functions of the video signal processing unit 26 can be realized by a processor such as a CPU or GPU included in the display device 200. At least one of the range extension unit 62, the decoder 64, and the correction processing unit 66 may be part of the first controller 21 described above.

[0038] The first signal sent from the output device 100 to the display device 200 via the first transmission path 10 is a video signal representing the test pattern 42. The first signal temporarily stored in the video memory 24 is read out by the first controller 21 and sent to the display panel 28 via the range extension unit 62, the decoder 64, and the correction processing unit 66, whereby it is displayed as an image on the display panel 28.

[0039] The range extension unit 62 of the video signal processing unit 26 converts the range of the video signal to, for example, a full range equivalent in accordance with metadata included in the video signal or settings on the display device 200 side. For example, if the display device 200 is set to full range and the first signal transmitted from the output device 100 via the first transmission path 10 is in limited range, the range extension unit 62 maps pixel values ​​in the range of 64 to 940 to a range of 0 to 1023. Note that if the first signal is in the full range, the range extension unit 62 does not perform such mapping. The decoder 64 converts the first signal (e.g., a YCbCr digital video signal) after range extension processing into RGB format. The correction processing unit 66 performs various corrections, such as gamma correction, on the signal converted to RGB format. These functions may be implemented by a single processor, or each function may be implemented individually by multiple processors.

[0040] (Step S2 of Obtaining Comparison Data) Next, the first controller 21 of the display device 200 obtains "comparison data" obtained from the signal read out from the video memory 24. The first controller 21 can obtain the comparison data in response to a request from the output device 100. For example, the second controller 12 of the output device 100 sends an instruction to the first controller 21 of the display device 200 via the second transmission path 20 to obtain the pixel value of a pixel (e.g., a first pixel) at a specific position in the test pattern.

[0041] Here, the "comparison data" is data related to the pixel value of the first pixel, obtained from the first signal that has reached the display device 200 via the first transmission path 10. In this embodiment, the first pixel may be one of the pixels that constitute the first color patch C1 of the test pattern 42. Here, as schematically indicated by the dashed arrow BL in FIG. 8 , the first controller 21 obtains, as the pixel value of the first pixel, the RGB value of a certain pixel included in the first color patch C1 of the test pattern 42, from the RGB values ​​obtained after decoding by the decoder 64. In other words, here, the first controller 21 obtains a signal that is output from the video memory 24 and has not yet been input to the source driver of the display panel 28.

[0042] At this time, the first controller 21 may acquire, in addition to the pixel value of the first pixel, pixel values ​​of one or more other pixels included in the first color patch C1. For example, the first controller 21 may acquire the pixel value of the first pixel and the pixel values ​​of multiple pixels adjacent to the first pixel as "comparison data." In other words, the number of pixel values ​​extracted from one color patch may be two or more.

[0043] The first controller 21 may acquire, as comparison data, pixel values ​​of a plurality of pixels including the first pixel, for example, a plurality of pixels included in a predetermined region centered on the first pixel (e.g., a region including a total of nine pixels arranged in three rows and three columns). As described later, in comparing the comparison data with the "read expected value" described later, values ​​obtained by performing statistical processing on the pixel values ​​of the plurality of pixels may be used. Examples of values ​​obtained by performing statistical processing on the plurality of pixel values ​​include the average and median. The statistical processing may be performed on the pixel values ​​of a plurality of spatially different pixels or on the pixel values ​​of a plurality of temporally different pixels (e.g., temporal arithmetic mean). Of course, this is not limited to these, and the pixel value of the first pixel itself may also be used as comparison data. In this sense, in this embodiment, it can be said that the first controller 21 acquires at least the pixel value related to the first pixel from the output of the video memory 24.

[0044] Here, similar to the pixel value for the first pixel, the first controller 21 acquires pixel values ​​for one or more of the plurality of pixels constituting the second color patch C2 in the test pattern 42 and pixel values ​​for one or more of the plurality of pixels constituting the third color patch C3 from the output of the video memory 24. These acquired pixel values ​​may be temporarily stored in RAM (not shown in FIG. 8 ) of the display device 200. Hereinafter, for ease of explanation, the one or more pixel values ​​acquired by the first controller 21 from the output of the video memory 24 may be collectively referred to as "comparison data."

[0045] The comparison data may be acquired by sampling a plurality of color patches included in one frame of a still image, or by sampling a plurality of frames displayed in time sequence. For example, as the first signal, a video signal representing a test pattern including a first color patch C1, a video signal representing a test pattern including a second color patch C2, and a video signal representing a test pattern including a third color patch C3 may be sent from the output device 100 to the display device 200 in time sequence. In this case, the pixel values ​​of the pixels constituting the first color patch C1, the pixel values ​​of the pixels constituting the second color patch C2, and the pixel values ​​of the pixels constituting the third color patch C3 may be acquired in time sequence by the first controller 21.

[0046] The first controller 21 may extract and acquire pixel values ​​at designated positions in the test pattern using any known method. Techniques for acquiring the gradation of a pixel at a designated position (and, if necessary, the coordinate values ​​of that pixel) are also described in, for example, U.S. Patent Application Publication Nos. 2019 / 172383 and 2004 / 246276. The entire disclosures of U.S. Patent Application Publication Nos. 2019 / 172383 and 2004 / 246276 are incorporated herein by reference.

[0047] After obtaining the comparison data, the first controller 21 sends the comparison data as a second signal to the output device 100. The transmission of the second signal between the display device 200 and the output device 100 is performed via a second transmission path 20. Here, unlike the first signal, the second signal is digital data that has not been converted into a YCbCr digital video signal or the like.

[0048] (Step S3 of determining whether or not there is a mismatch between the comparison data and the read expected value) The comparison data sent via the second transmission path 20 is received by, for example, the second controller 12 of the output device 100 (see FIG. 1 ). In this example, the comparison data is passed to the analysis unit 30 via the second controller 12.

[0049] Upon receiving the comparison data, the second controller 12 or the analysis unit 30 acquires from the memory 14 the pixel value (here, (64, 64, 64) as RGB values) for the first pixel in the test pattern stored in the memory 14. Here, for example, the analysis unit 30 acquires not only the pixel value of the first pixel but also the pixel value of a pixel in the test pattern 42 stored in the memory 14 that is located at a position corresponding to the pixel whose pixel value was acquired from the output of the video memory 24 by the first controller 21 of the display device 200.

[0050] The memory 14 may store in advance the pixel values ​​of the pixels that make up the test pattern, linked to their position coordinates. The position coordinates and pixel values ​​of each of the pixels that make up the test pattern are known. Therefore, the pixel value of a pixel that is located at a position corresponding to a pixel whose pixel value has been acquired by the first controller 21 can be easily acquired by specifying the position of the desired pixel in the test pattern.

[0051] The pixel values ​​acquired from the memory 14 by the second controller 12 or the analysis unit 30 are pixel values ​​before the output device 100 outputs the first signal to the first transmission path 10, and are values ​​that are expected to be acquired by the first controller 21 in the display device 200. In other words, if there is no error in the transmission of the first signal via the first transmission path 10, the pixel values ​​actually acquired by the first controller 21 in the display device 200 should match pixel values ​​acquired directly from the memory 14 without going through the first transmission path 10 (which may also be called "original data"). Hereinafter, one or more pixel values ​​acquired from a test pattern prepared in advance will be referred to as "read-out expected values" in comparison with "comparison data."

[0052] The expected read value may be given in the form of a pair of position coordinates and pixel values ​​for one or more pixels in the test pattern. The expected read value may be acquired based on an instruction from the first controller 21 of the display device 200 via the second transmission path 20. The order of acquiring the comparison data and the expected read value is arbitrary. The expected read value may be acquired prior to receiving the comparison data.

[0053] The analysis unit 30 compares the comparison data with the expected read value. In other words, the analysis unit 30 verifies whether the comparison data matches the expected read value expected from the original data. For example, for a first pixel, assume that the pixel value acquired by the first controller 21 from the output of the video memory 24 is 64, and the pixel value acquired from the memory 14 of the output device 100, i.e., the expected read value, is also 64. This means that there is little possibility of an inconsistency occurring between the range setting in the output device 100 and the range setting in the display device 200.

[0054] The comparison between the comparison data and the expected read value is not limited to a comparison between a single pixel and may be performed for multiple pixels. For example, the analysis unit 30 may perform a pixel-by-pixel comparison between multiple pixel values ​​as comparison data acquired from the output of the video memory 24 by the first controller 21 and multiple pixel values ​​constituting the expected read value acquired from the test pattern stored in the memory 14 of the output device 100. In this case, the comparison data may include pixel values ​​of multiple pixels including the first pixel, and the expected read value may include pixel values ​​of multiple pixels in the first color patch C1. If the multiple pixel values ​​in the comparison data match the multiple pixel values ​​in the expected read value, it can be determined that no inconsistency has occurred in the range settings. Therefore, in this case, the analysis unit 30 determines that no inconsistency has occurred between the comparison data and the expected read value. In other words, the analysis unit 30 determines that no error has occurred in the signal transmission via the first transmission path 10.

[0055] On the other hand, for example, with respect to the first pixel, if the pixel value acquired from the memory 14 of the output device 100 is 64 and therefore the pixel value expected to be acquired from the output of the video memory 24 by the first controller 21 is 64, but the pixel value actually acquired by the first controller 21 is different from 64, it is expected that some error has occurred in the signal transmission via the first transmission path 10. Therefore, in this case, the analysis unit 30 determines that there is an inconsistency in the comparison result between the comparison data and the read-out expected value.

[0056] A discrepancy between the pixel value of the read expected value and the pixel value of the comparison data occurs, for example, when the range settings are inconsistent between the output device 100 and the display device 200. For example, if the output device 100 is set to "full range (also called "Full Levels")" and the display device 200 is set to "limited range (also called "Video Levels")," the first controller 21 is expected to obtain a pixel value of "64" from the output of the video memory 24, but the pixel value of the comparison data that is actually obtained is 0, not 64. In this way, the analysis unit 30 determines whether or not there is a discrepancy between the comparison data and the read expected value.

[0057] (Step S4 of presenting a solution according to the type of inconsistency to the user) Furthermore, when the analysis unit 30 obtains a determination result that there is an inconsistency in the comparison result between the comparison data and the read expectation value, it presents a solution to resolve the inconsistency between the read expectation value and the comparison data to the user of the display device 200. For example, when an inconsistency is found between the read expectation value and the comparison data, the analysis unit 30 displays a message 29 such as "There may be an error in the video range. Is the input signal set to full range and the monitor setting set to limited range?" on the display panel 28 of the display device 200, as exemplified in FIG. 9 .

[0058] In the past, when an operator noticed that the color of an image displayed on a monitor deviated from the intended color, the operator would manually adjust the color on the monitor by overlaying an on-screen display (OSD) or the like on the monitor screen. Specifically, the operator had to manually obtain pixel values ​​of pixels at specified positions and display them on the OSD, while adjusting various monitor parameters based on their own experience to approach the target color. Furthermore, it was difficult for an inexperienced operator to detect the deviation from the intended color.

[0059] In contrast, according to the embodiment of the present invention, the verification system 1 itself analyzes the mismatch in settings between the output device 100 and the display device 200, making it possible to verify signal transmission in a manner that does not depend on the proficiency of the operator. Furthermore, the verification system 1 presents a solution depending on the type of mismatch between the read expected value and the comparison data, making it possible to efficiently resolve the mismatch in settings.

[0060] In the example described above, in step S2 of acquiring the comparison data, the first controller 21 acquires pixel values ​​converted into RGB video signals (see FIG. 8 ). However, the present invention is not limited to this example. The first controller 21 may acquire, as the comparison data, raw data that is input to the range extension unit 62, as shown schematically by the dotted arrow DL in FIG. 8 . When raw data is used as the comparison data, if the display device 200 is set to, for example, a full range, the raw data may be converted into data corresponding to the full range of RGB by at least one of the first controller 21, the second controller 12, and the analysis unit 30, and then it may be determined whether or not there is a mismatch between the comparison data and the readout expected value.

[0061] 4. Specific Examples of Extracting Solutions According to the Type of Mismatch (Example 1 of Error Cause Estimation) Here, examples of classifying mismatches and extracting solutions according to the mismatch will be described in more detail with reference to FIGS. 10 to 12. FIG. 10 shows an example of comparison data obtained when the test pattern 42 shown in FIG. 3 is used. FIG. 10 specifically shows, using a 10-bit video signal as an example, how the obtained comparison data, i.e., RGB values, can change depending on whether the output device 100 and the display device 200 are limited range or full range.

[0062] First, let's look at the top-left entry of the four entries in the table shown in Figure 10. The three numerical values ​​(64, 64, 64) in the first row of this entry indicate the RGB values ​​of a pixel (e.g., the first pixel) in the first color patch C1, among the RGB values ​​obtained as the comparison data. Similarly, the second row of this entry indicates the RGB values ​​of a pixel in the second color patch C2, among the comparison data, and the third row indicates the RGB values ​​of a pixel in the comparison data that is included in the third color patch C3.

[0063] As can be seen from the numerical values ​​shown in the upper left entry in the table, when the output device 100, which is the source of the first signal, is set to a limited range and the display device 200 is also set to a limited range, the RGB values ​​acquired as the comparison data also match the RGB values ​​of the expected read values: (64, 64, 64), (512, 512, 512), and (940, 940, 940). Similarly, as shown in the lower right entry in the table, even when both the output device 100 and the display device 200 are set to a full range, there is no difference between the RGB values ​​acquired as the comparison data and the RGB values ​​of the expected read values. In other words, as long as the range settings of the output device 100 and the display device 200 are the same, there is essentially no discrepancy between the comparison data and the expected read values.

[0064] On the other hand, if there is a mismatch in the range settings between the output device 100 and the display device 200, the RGB values ​​of the comparison data will deviate from the RGB values ​​of the expected read values. For example, take a look at the entry in the bottom left of the table shown in Figure 10 (indicated by the dashed rectangle E1 in Figure 10). This shows an example of comparison data acquired when the output device 100 is set to full range and the display device 200 is set to limited range. It can be seen from Figure 10 that the RGB values ​​for the pixel in the first color patch C1 are (0, 0, 0), and the RGB values ​​for the pixel in the third color patch C3 are (1023, 1023, 1023).

[0065] Because the output device 100 is a full-range device, the input signal to the display device 200 is expressed in gradations of 0 to 1023. However, if the display device 200 is a limited-range device, only the gradation range of 64 to 940 can be expressed. As a result, all pixels with gradations of 0 to 63 are crushed to the darkest gradation of 0 on the display device 200, and all pixels with gradations of 941 to 1023 are crushed to the brightest gradation of 1023 on the display device 200. In other words, the gradation cannot be expressed as intended, and the pixels constituting the first color patch C1 and the pixels constituting the third color patch C3 are expressed as pure black and pure white, respectively, on the display device 200. Therefore, in this case, the verification system 1 presents the operator with a message such as, "There may be an error in the video range. Is the input signal set to full range and the monitor setting set to limited range?" (see FIG. 9 ).

[0066] Conversely, when the output device 100 is set to a limited range and the display device 200 is set to a full range, the gradation cannot be displayed as intended on the display device 200. When the output device 100 is set to a limited range and the display device 200 is set to a full range, the signal input to the display device 200 remains within the full range of 64 to 940 (without expansion). Therefore, in the display device 200, for example, a pixel in the first color patch C1 is displayed on the display panel 28 as a pixel having RGB values ​​of (119, 119, 119) (see FIG. 10), and a pixel in the third color patch C3 is displayed on the display panel 28 as a pixel having RGB values ​​of (869, 869, 869) (see FIG. 10). In other words, the video content is displayed on the display device 200 as an image lacking in contrast. In such a case, the verification system 1 displays a message to the operator such as, "There may be an error in the video range. Is the input signal set to limited range and the monitor setting set to full range?"

[0067] In this way, when a discrepancy occurs between the comparison data and the expected read value, there is a certain tendency in the discrepancy between the RGB values, and the cause of the discrepancy between the comparison data and the expected read value can be inferred by analyzing the comparison data. More specifically, by classifying the discrepancy between the comparison data and the expected read value into multiple classes and identifying which class the actual discrepancy corresponds to, an effective solution to the discrepancy can be extracted. In the example of FIG. 10 , if comparison data similar to the entry in the bottom left of the table is acquired, the verification system 1 can display a message such as "Are the input signal set to full range and the monitor setting set to limited range?", and if comparison data similar to the entry in the top right is acquired, the verification system 1 can display a message such as "Are the input signal set to limited range and the monitor setting set to full range?"

[0068] According to this embodiment, it is possible to extract solutions that are considered to be effective in resolving image quality degradation, regardless of the operator's level of proficiency. Extraction and presentation of solutions according to the type of inconsistency between pixel values ​​may be achieved using a rule-based method or a trained model using machine learning. Obtaining training data is relatively easy, and when using machine learning, it is sufficient to build a trained model that estimates problem areas in light of past trends.

[0069] In determining whether or not there is a mismatch between the comparison data and the read-out expected value, when pixel values ​​of multiple pixels are compared between the comparison data and the read-out expected value, a mismatch may be determined if even one pixel pair is found to be mismatched. Furthermore, when pixel values ​​of multiple pixels are used to verify video signal transmission, a statistically processed value of the multiple pixel values ​​acquired by the first controller 21 may be compared with the read-out expected value. For example, a comparison may be made between the average value of multiple pixel values ​​in the comparison data and the pixel value of a pixel in the read-out expected value. For example, an averaging filter with a three-row, three-column arrangement centered on a first pixel may be applied to the comparison data, and the pixel value of the pixel in the read-out expected value corresponding to the first pixel may be compared. The use of averaging can avoid erroneous determinations due to unevenness in compression, etc.

[0070] The statistical processing of the plurality of pixel values ​​acquired by the first controller 21 may be performed by the analysis unit 30 of the output device 100 or the second controller 12, or may be performed by the first controller 21 of the display device 200. When the statistical processing is performed on the pixel values ​​by the first controller 21, the data on which such statistical processing has been performed may be passed to the second controller 12 via the second transmission path 20.

[0071] When comparing pixel values ​​of the comparison data or values ​​obtained by performing statistical processing on pixel values ​​with corresponding pixel values ​​of the read expected value, a "match" is not determined only when they are exactly equal, but may be determined to be equal if the difference between the compared values ​​is within a predetermined range. For example, a match may be determined when the difference between pixel values ​​of common position coordinates is within a predetermined range. For example, a "match" may be determined when the deviation of the pixel value of the comparison data from the read expected value for each of R, G, and B is less than ±3.

[0072] For example, when a YUV video signal is used to transmit a video signal, even if there is no mismatch in the settings between the output device 100 and the display device 200, there may be a discrepancy of 2 to 3 pixels in the pixel values ​​after decoding. By providing a certain degree of flexibility in the range of what is determined to be a "match," it is possible to avoid erroneous determinations due to overly strict criteria. The threshold for determining whether a match or mismatch occurs may be configured to be flexibly changeable after the fact.

[0073] (Example 2 of Error Cause Estimation) By using the test pattern 43 shown in FIG. 4 instead of or in addition to the above-described test pattern 42, it is possible to detect whether or not there is a bit depth mismatch. As described with reference to FIG. 4, the test pattern 43 includes four color patches whose pixel values ​​differ by one in the gradation direction, namely, a first color patch M1, a second color patch M2, a third color patch M3, and a fourth color patch M4. If, in the comparison data acquired from the output of the video memory 24, the difference in pixel values ​​between two color patches whose pixel values ​​differ by one in the gradation direction is greater than 0 and less than 3, it can be said that the bit depth setting of both the output device 100 and the display device 200 is 10 bits.

[0074] On the other hand, if the difference in pixel values ​​between the two color patches is 0 or 3 or more, it is possible that the bit depth of the display device 200 is set to 8 bits. Therefore, in this case, the analysis unit 30 of the output device 100 determines that the comparison data does not match the expected read value, and sends a command to the first controller 21 of the display device 200 to display on the display panel 28 a message such as "The bit depth is 8 bits. If you are planning to display in 10 bits, there is a possibility that the bit depth setting is incorrect."

[0075] Note that, in detecting the presence or absence of a bit depth inconsistency, it is not essential that the video signal processing unit 26 of the display device 200 include the range extension unit 62 and the decoder 64. On the other hand, in order to detect the above-mentioned inconsistency in range settings, it is sufficient that the video signal processing unit 26 includes at least the range extension unit 62. The range in the display device 200 can be determined by changing the setting of the range extension unit 62 using the first controller 21.

[0076] (Example 3 of Error Cause Estimation) As described above, by using a test pattern that includes, in addition to a certain color patch, other color patches whose pixel values ​​differ in the gradation direction by a predetermined value or more, it is possible to expose a setting error in the gradation direction. Alternatively, or in addition to this, by using a test pattern that includes multiple color patches, each of which is a chromatic color, it is possible to find a setting error in the color direction, as will be described below.

[0077] Fig. 11 shows a first example of comparison data obtained when using the test pattern 44 shown in Fig. 5. As described with reference to Fig. 5, the test pattern 44 includes, as first to third regions, three color patches, each expressed in a single color of red, green, or blue, namely, a first color patch R1, a second color patch G2, and a third color patch B3.

[0078] FIG. 11 specifically illustrates how the RGB values ​​acquired by the first controller 21 may change depending on whether the color gamut standards assumed by the output device 100 and the display device 200 are BT.709, DCI-P3, or BT.2020, respectively. As can be seen from the RGB values ​​in the diagonal entries at the top left, center, and bottom right in the table shown in FIG. 11, if there is no mismatch in the color gamut standards between the output device 100 and the display device 200, pixel values ​​that match the expected read values ​​can be expected for each of the first color patch R1 to the third color patch B3. In other words, the color hues of each of the first color patch R1 to the third color patch B3 should be correctly reproduced on the display device 200.

[0079] When such RGB values ​​are acquired as the comparison data, the analysis unit 30 determines that the color gamut standard of the output device 100 matches the color gamut standard of the display device 200. Note that, in determining whether the color gamut standard settings of the output device 100 and the display device 200 match, the pixel values ​​may be determined to match not only when the difference between the pixel values ​​of the comparison data and the pixel values ​​of the read-out expected values ​​is zero, but also when these differences are within a predetermined range. For example, for each of the colors R, G, and B, it may be determined that the pixel values ​​of the comparison data match when the pixel values ​​of the read-out expected values ​​are within a range of less than ±3.

[0080] In contrast, in entries other than the upper left, center, and lower right entries in the table shown in FIG. 11 (i.e., non-diagonal entries), the RGB values ​​for each color patch deviate from the expected read RGB values. For example, if the color gamut standard of the output device 100 complies with BT.2020 and the color gamut standard of the display device 200 complies with BT.709, the RGB values ​​for each color patch deviate from the expected read RGB values, as shown in the lower left entry in the table. In the example shown in FIG. 11, the gradation for each pixel of each color patch deviates by 3 or more from 512. Therefore, if comparison data such as that shown in the lower left entry in the table is obtained, the analysis unit 30 of the output device 100, for example, displays a message such as "There may be an error in the color gamut setting. Is the input signal set to BT.2020 and the monitor setting set to BT.709?" on the display panel 28.

[0081] (Example 4 of Error Cause Estimation) Fig. 12 shows a second example of comparison data obtained when using the test pattern 44 shown in Fig. 5. As will be explained below, by using a test pattern including a plurality of chromatic color patches, it becomes possible to estimate, from the trend of the comparison data, not only whether or not there is an error in the setting of the color gamut standard, but also whether or not there is an error in the conversion coefficients.

[0082] As can be understood from the above description, the test pattern 44 can be transmitted from the output device 100 to the display device 200 via the first transmission path 10 in the form of, for example, a YCbCr digital video signal. As is well known, RGB signals and YCbCr signals can be converted to each other using a predetermined relational expression. However, the coefficients in the relational expression used for this conversion (hereinafter simply referred to as "conversion coefficients") vary depending on the applicable color gamut standard. If the conversion coefficients from the RGB signals representing the test pattern to the YCbCr signals are not set correctly, the intended color tone cannot be reproduced.

[0083] The RGB values ​​shown in FIG. 12 are another example of comparison data that can be acquired depending on whether the color gamut standard assumed by the output device 100 and the display device 200 is BT.709 or BT.2020, respectively. When the conversion coefficients are set correctly, as shown in the diagonal entries (the upper left entry and the lower right entry) in the table shown in FIG. 12 , the RGB values ​​of the pixels in each color patch will be close to 512 for one of R, G, and B, and close to 0 for the remaining two. Even when there is no mismatch in the color gamut standard, the pixel values ​​will not be exactly 512 or 0 due to factors such as multiplication and division using shift registers and rounding to integer values. In this sense, for each of the R, G, and B colors, if the difference in pixel values ​​of pixels with common position coordinates between the comparison data and the read expected value is within a predetermined range, it may be determined that they match. For example, it may be determined that they match if the pixel value of the comparison data is within a range of less than ±3 relative to the pixel value of the read expected value.

[0084] In contrast, if there is a mismatch in the color gamut standards between the output device 100 and the display device 200, the hue of the color patch displayed on the display device 200 will deviate from the original hue of one of the three primary colors. For example, if the color gamut standard of the output device 100 complies with BT.2020 and the color gamut standard of the display device 200 complies with BT.709, the RGB values ​​for each color patch will deviate from the expected RGB values, as shown in the entry at the bottom left of the table. In the example shown in FIG. 12 , the comparison data for the first pixel of the first color patch R1 is (538, 28, 3), indicating a hue deviation from pure red. Furthermore, the pixel value of the pixel included in the third color patch B3 also deviates by more than 5 from 512. Therefore, when comparison data such as that shown in the lower left entry in the table is obtained, the analysis unit 30 of the output device 100, for example, displays a message such as "There may be an error in the RGB to YCbCr conversion coefficient. Is the input signal set to BT.2020 and the monitor setting set to BT.709?" on the display panel 28, prompting the operator to reset the settings.

[0085] Both the table shown in FIG. 11 and the table shown in FIG. 12 are examples of RGB values ​​acquired by the first controller 21 when the test pattern 44 shown in FIG. 5 is used. Whether the mismatch between the read expected value and the comparison data is due to an error in the conversion coefficients or a mismatch in the color gamut standard can be determined by examining which of the off-diagonal entries in these tables the actually acquired RGB value set is closest to. For example, in the table shown in FIG. 12, when the arrangement of nine numerical values ​​shown in each entry in the table is considered as a three-row, three-column matrix, the bottom-left entry and the top-right entry resemble an upper triangular matrix or a lower triangular matrix. If such a tendency is observed in the comparison data, it is highly likely that the conversion coefficients from RGB signals to YCbCr signals are not set correctly.

[0086] The conversion coefficients for converting an RGB signal into a YCbCr signal can be determined by changing the settings of the decoder 64 (see FIG. 8 ) using the first controller 21. In this sense, in order to detect errors in the conversion coefficients, the video signal processing unit 26 of the display device 200 only needs to include the decoder 64. Note that, in order to detect a mismatch in the color gamut standard, the range extension unit 62 and the decoder 64 may be omitted from the video signal processing unit 26 if certain conditions are met. This is because, if the display device 200 is set to full range and the signal sent from the output device 100 is a full-range RGB format signal, the first controller 21 can obtain full RGB data as comparison data from the output of the video memory 24.

[0087] In the example described here, the pixel value of the first color patch R1, the second color patch G2, and the third color patch B3 are all 512. However, it is not essential that the pixel values ​​be equal among the multiple color patches. If the tendency for the comparison data to deviate from the expected read value due to an error in the conversion coefficient or a mismatch in the color gamut standard is understood in advance, it is possible to estimate the cause of the error in signal transmission, regardless of whether the pixel values ​​are equal among the multiple color patches.

[0088] As described above, according to the embodiment of the present invention, by applying a test pattern including color patches having predetermined pixel values, it is possible to verify whether or not there is an error in setting the gradation direction and / or the color direction, more specifically, whether or not there is an inconsistency in the range, bit depth, or color gamut standard, whether or not there is an error in the conversion coefficient, etc. The test patterns exemplified may be used independently, or two or more of them may be combined and used in the form of a single test pattern.

[0089] 5. Modified Example of Verification System As described above, in the configuration illustrated in FIG. 1 , the display device 200 includes a display panel 28 such as a liquid crystal display panel. In step S2 of acquiring comparison data, the first controller 21 may display an image (typically a test pattern) based on the first signal input to the video memory 24 on the display panel 28. In this case, in addition to displaying the image based on the first signal, the first controller 21 may also display a cursor, text, or the like superimposed on the image on the display panel 28. For example, in response to an instruction from the second controller 12 of the output device 100, the first controller 21 may display the position coordinates and pixel value of a first pixel on the display panel 28, superimposed on the image based on the first signal (here, test pattern 42), as schematically shown in FIG. 13 . For example, an operation on the output device 100 may display a cursor superimposed on the test pattern, and a pixel whose pixel value is to be acquired may be designated by the cursor. By displaying the position coordinates and pixel value of the pixel pointed to by the cursor near the cursor, the operator can obtain the pixel value (here, comparison data) of the desired pixel by an intuitive operation.

[0090] Fig. 14 schematically shows a first modified example of the verification system of the present invention. Compared to the verification system 1 shown in Fig. 1, the verification system 1A shown in Fig. 14 includes an output device 100A having a display panel 18 instead of the output device 100. With this configuration, the second controller 12 of the output device 100A can display, for example, a test pattern 42 on the display panel 18.

[0091] In the above-described embodiment, the second controller 12 acquires the pixel value of a pixel at a specified position in the test pattern 42 before determining whether or not there is a mismatch between the expected read value and the comparison data. That is, the second controller 12 acquires the expected read value. The pixel value of a pixel (e.g., the first pixel) in the test pattern 42 may be acquired by superimposing a cursor or the like on the test pattern 42 on the display panel 18 and specifying the pixel at the cursor position. In this way, the expected read value may be extracted from the image of the test pattern. Alternatively, the expected read value may be prepared in advance in the form of metadata together with the image file of the test pattern.

[0092] 14 , in the step S2 of acquiring the comparison data, the position coordinates and pixel value of the first pixel may be displayed on the display panel 18 of the output device 100A, instead of on the display panel 28 of the display device 200, by superimposing them on an image (e.g., test pattern 42) based on the first signal. Furthermore, in the case where the output device 100A has the display panel 18, in the step S4 of presenting the solution, the solution may be presented through display on the display panel 18 of the output device 100A under the control of the second controller 12. In this case, the second controller 12 may display the pixel value acquired by the first controller 21 and the position coordinates of the pixel targeted for acquisition, along with the solution, on the display panel 18. The display of the pixel value and position coordinates of the specified pixel is not limited to being displayed on an OSD.

[0093] 1 and 14, control related to parts other than the acquisition of comparison data can basically be assigned to the second controller 12. According to such a configuration, if the display device has a function of extracting the pixel value of a pixel at a specified position, by connecting the output device 100 or the output device 100A to such a display device, it becomes possible to construct a verification system according to an embodiment of the present invention and apply the above-described verification method.

[0094] Instead of sending the comparison data to the output device via the second transmission path 20, the display device may receive the read expected value and perform processing such as determining whether or not there is an error on the display device side. Figure 15 schematically shows a second modified example of the verification system of the present invention. The verification system 1B shown in Figure 15 includes an output device 100B, a display device 200B, and a first transmission path 10 connecting them.

[0095] 14 , the output device 100B of the verification system 1B has a second controller 12. However, unlike the output device 100A, the output device 100B of the verification system 1B does not have an analysis unit 30. On the other hand, the display device 200B of the verification system 1B has an analysis unit 30B connected to the first controller 21. The analysis unit 30B may be realized as a part of the first controller 21.

[0096] The analysis unit 30B of the display device 200B has the same functions as the analysis unit 30 in each of the above-described examples. In the example shown in FIG. 15 , the analysis unit 30B compares the read expected value acquired from the memory 14 by the second controller 12 and sent to the first controller 21 via the second transmission path 20 with the comparison data acquired by the first controller 21. Based on the comparison between the read expected value and the comparison data, the analysis unit 30B determines whether or not there is an inconsistency between the data. If the analysis unit 30B determines that an inconsistency exists between the data, the analysis unit 30B presents the user with a solution corresponding to the type of inconsistency between the data. The analysis unit 30B, for example, displays the solution on the display panel 28 of the display device 200B.

[0097] In addition, the part that realizes the function of determining whether or not there is an inconsistency and the part that realizes the function of presenting a solution may be distributed and arranged in both the output device and the display device. In the third modified example shown in Figure 16, a verification system 1C is constructed from an output device 100C, a display device 200C, and a first transmission path 10 and a second transmission path 20 that connect them to each other.

[0098] 16, the output device 100C and the display device 200C each have a determination unit 33 and a solution presentation unit 34. The determination unit 33 executes step S3 of determining whether or not there is an inconsistency between the comparison data and the read expected value, and the solution presentation unit 34 executes step S4 of presenting a solution. In the configuration illustrated in FIG. 16, the set of the determination unit 33 and the solution presentation unit 34 as a whole realizes the function of the analysis unit 30C.

[0099] Conversely, the part that realizes the function of determining whether or not there is a data inconsistency may be located on the display device side, and the part that realizes the function of presenting a solution may be located on the output device side. Figure 17 shows a schematic diagram of a verification system 1D according to a fourth modification of the verification system of the present invention. The verification system 1D includes an output device 100D having a solution presenting unit 34 and a display device 200D having a determination unit 33, and the combination of the solution presenting unit 34 and the determination unit 33 realizes an analysis unit 30D of the verification system 1D.

[0100] In the above examples, the second controller 12 of the output device acquires the read expected value. However, this is not limited to these examples, and the read expected value may be prepared in advance in a memory on the display device side. For example, as shown in FIG. 15 , when the display device has an analysis unit 30B, connecting the display device to the output device that sends the first signal makes it possible to execute the above-described verification method on the display device side. In this way, the means for verifying signal transmission may be provided in the form of a display device capable of executing the verification method of the present invention.

[0101] The means for verifying signal transmission may be provided in the form of a verification program containing instructions for causing a processor or the like to execute the verification method of the present invention. The verification program may be provided via a telecommunications line or recorded on a computer-readable non-transitory recording medium such as an optical disc. The verification program may be downloaded via a telecommunications line or read from an optical disc and installed in a storage device provided in a personal computer or the like. The verification method of the above-described embodiment can be realized by connecting, for example, a personal computer on which the verification program is installed to a display device having a function for acquiring pixel values ​​of pixels at specified positions.

[0102] 1, 1A to 1D: Verification system, 10: First transmission path, 12: Second controller, 14: Memory, 16: Image processing unit, 18: Display panel, 20: Second transmission path, 21: First controller, 22: Display panel, 24: Video memory, 26: Video signal processing unit, 28: Display panel, 30, 30B to 30D: Analysis unit, 33: Determination unit, 34: Solution presentation unit, 41 to 44: Test patterns, 61: Color management unit, 62: Range extension unit, 63: Encoder, 64: Decoder, 65: Range conversion unit, 66: Correction processing unit, 100, 100A to 100D: Output device, 200, 200B to 200D: Display device, C1, M1, R1: First color patch, C2, G2, M2: Second color patch, B3, C3, M3: Third color patch, M4: Fourth color patch

Claims

1. A verification system for video signal transmission, comprising a display device, a first transmission line, an output device, and an analysis unit, wherein the display device has a first controller, and the analysis unit compares comparison data acquired by the first controller with a read expected value expected as a value acquired by the first controller, where the comparison data is data related to the pixel value of a first pixel obtained from a first signal sent from the output device to the display device via the first transmission line, the first signal being a video signal representing a first image having a first region including the first pixel, and the analysis unit presents a solution corresponding to the type of the inconsistency to the user of the display device when an inconsistency is found in the comparison result between the comparison data and the read expected value.

2. The verification system according to claim 1, wherein the display device further has a video memory, the video memory temporarily holds the first signal, and the first controller acquires at least the pixel value related to the first pixel from the output of the video memory in response to a request from the output device.

3. The verification system according to claim 1 or claim 2, wherein the output device has a second controller, and the first controller of the display device executes acquisition of the comparison data in response to a request from the second controller of the output device.

4. The verification system according to claim 3, wherein at least one of the output device and the display device further has a display panel, and the second controller of the output device causes the solution to be displayed on the display panel.

5. The verification system according to claim 4, wherein the display device has the display panel, and the position coordinates and pixel value of the first pixel are displayed on the display panel.

6. The verification system according to any one of claims 1 to 5, wherein the analysis unit is part of the output device, and the first controller of the display device causes the comparison data to be sent from the display device to the output device as a second signal.

7. The verification system according to any one of claims 1 to 6, wherein in the comparison between the read expected value and the comparison data, when the difference between the pixel values with the same position coordinates is within a predetermined range, the analysis unit determines that they match.

8. The verification system according to any one of claims 1 to 7, wherein the first controller acquires pixel values of a plurality of pixels including the first pixel as the comparison data, the read expected value includes pixel values of a plurality of pixels included in the first region, and in determining the presence or absence of inconsistency between the comparison data and the read expected value, the analysis unit performs a pixel-by-pixel comparison between the plurality of pixel values acquired by the first controller and the plurality of pixel values constituting the read expected value.

9. The verification system according to any one of claims 1 to 7, wherein the first controller acquires pixel values of a plurality of pixels including the first pixel as the comparison data, and in determining the presence or absence of inconsistency between the comparison data and the read expected value, the analysis unit compares a value obtained by performing statistical processing on the plurality of pixel values acquired by the first controller with the read expected value.

10. The verification system according to any one of claims 1 to 9, wherein the first controller acquires pixel values after conversion into an RGB video signal.

11. The verification system according to any one of claims 1 to 10, wherein the first image further includes (1) a second region in which pixel values are different by a predetermined value or more in the gradation direction as compared with the first region, (2) four or more regions including the first region and including four or more regions in which pixel values are different by one in the gradation direction, or (3) further includes a third region and a fourth region in addition to the first region, and the first region, the third region, and the fourth region are three regions each composed of a different one of the three primary colors.

12. A display device comprising a first controller and an analysis unit, wherein the analysis unit compares comparison data acquired by the first controller with a read expected value expected as a value acquired by the first controller. Here, the comparison data is data related to the pixel value of a first pixel obtained from a first signal input to the display device via a first transmission path, and the first signal is a video signal representing a first image having a first region including the first pixel. The display device, wherein when the analysis unit finds an inconsistency in the comparison result between the comparison data and the read expected value, presents a solution corresponding to the type of the inconsistency to the user.

13. A method for verifying video signal transmission, comprising: a step (a) of sending a first signal via a first transmission path to a display device having a first controller, wherein the first signal is a video signal representing a first image having a first region including a first pixel; a step (b) of acquiring, by the first controller, as comparison data, data related to the pixel value of the first pixel obtained from the first signal sent to the display device via the first transmission path; and a step (c) of determining whether an inconsistency has occurred in the comparison result between the comparison data and a read expected value expected as a value acquired by the first controller, and extracting a solution corresponding to the type of the inconsistency.

14. A verification program for video signal transmission, including machine-readable instructions, which when executed by one or more processors, cause the one or more processors to: send a first signal via a first transmission path to a display device having a first controller, wherein the first signal is a video signal representing a first image having a first region including a first pixel; acquire, by the first controller, as comparison data, data related to the pixel value of the first pixel obtained from the first signal sent to the display device via the first transmission path; determine whether an inconsistency has occurred in the comparison result between the comparison data and a read expected value expected as a value acquired by the first controller; and extract a solution corresponding to the type of the inconsistency.

15. A computer-readable non-transitory recording medium having recorded thereon a computer program for causing a computer to execute the method according to claim 13.

16. A video signal transmission verification system, comprising: a display device having a video memory and a first controller; a first transmission path; an output device; and an analysis unit, wherein the video memory of the display device temporarily holds a first signal sent from the output device to the display device via the first transmission path, where the first signal is a video signal related to image data including at least one region, and the at least one region includes a first region having a first pixel; the first controller of the display device receives a request from the output device and acquires, as comparison data, a pixel value related to the first pixel from an output of the video memory; the analysis unit acquires, as original data, at least the comparison data and a pixel value related to the first pixel before the output device outputs the first signal to the first transmission path; the analysis unit verifies at least whether the comparison data matches a read expected value expected from the original data, and when there is a mismatch in the comparison between the comparison data and the read expected value, presents a solution according to the type of the mismatch to a user of the display device.

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