JP5309770B2 - Image transmitting apparatus and program thereof - Google Patents

Description

  The present invention relates to an image transmission device that transmits image data to an image reception device.

  Recently, an image transmission / reception system including a DVD player, which is a source device (image transmission device) compliant with the HDMI standard, and a display device, which is a sink device (image reception device), has been used. By including video data and audio data in the data, both video data and audio data can be transmitted to the sink device using a single HDMI cable. The display device converts the received HDMI data into the original video data and displays it.

  The HDMI data transmitted / received by these devices is encrypted by HDCP (High-bandwidth Digital Content Protection system), and the HDMI data can only be received after successful HDMI authentication between the HDMI transmitting unit and the HDMI receiving unit. Transmission and reception are made (Patent Document 1 below). Therefore, when the HDCP authentication fails between the HDMI transmission unit and the HDMI reception unit, the HDMI data is not transmitted.

  The resolution and color depth of video data transmitted from the DVD player to the display device (these are collectively referred to as a transmission clock frequency setting value) can be set by a user operation. For example, the DVD player acquires EDID (Extended display identification data) from the display device, and reads the resolution and color depth that can be supported by the display device included in the EDID. Then, the DVD player compares the resolution and color depth that can be supported by itself with the resolution and color depth that can be supported by the display device, displays the common supported resolution and color depth, and displays the desired resolution to the user. And select the color depth.

  Here, the DVD player transmits the HDMI data to the display device via the TMDS line of the HDMI cable. If the length of the HDMI cable is long (for example, 5 m or more), the resolution of the video data is high and the color is high. When the depth is deep (that is, when the transmission clock frequency is high), video data cannot be accurately transmitted from the DVD player to the display device. As a result, there is a problem that the display device cannot receive or decode video data correctly, and the display device cannot display video or noise is generated in the displayed video. Therefore, it is necessary to reselect the resolution and color depth by a user operation, and the operation is very complicated. In addition, whether the video data can be accurately transmitted by the combination of the resolution and the color depth is not known unless the user visually views the video on the display device, so it may be necessary to reselect the resolution and the color depth multiple times in some cases. Occurs.

JP 2007-288247 A

  The present invention has been made to solve the above-described conventional problems, and an object of the present invention is to accurately transfer image data adjusted to a transmission clock frequency setting value selected by a user operation from an image transmission apparatus to an image reception apparatus. It is to provide an image transmission apparatus that can transmit to the network.

An image transmission device according to a preferred embodiment of the present invention includes a connection unit that connects to an image reception device, a transmission unit that transmits image data to the image reception device, and each transmission clock frequency setting for a plurality of transmission clock frequency setting values. Verification data generation means for generating first verification data for verifying link consistency based on the image data adjusted to the value, and each transmission means for generating each image data generated with the first verification data The image receiving device generates second verification data for verifying link integrity by the image receiving device, and each time the second verification data is generated, the image receiving device Verification data reading means for reading second verification data, and first verification data generation means for generating the second verification data read by the verification data reading means By matching the verification data, and authentication means for executing authentication integrity link with the image receiving apparatus, by the authentication by the authenticating means, can set the authentication was successful the transmission clock frequency setting value by a user operation And a setting enabling means for making it impossible to set the clock frequency setting value that has failed in the authentication by a user operation.

First verification data for verifying link integrity is generated from the image data adjusted to the transmission clock frequency setting value, and the image data is transmitted to the image receiving device, and the image receiving device receives the image data. Generating second verification data for verifying link integrity from the image, and performing verification of link integrity with the image receiving device by comparing the first verification data with the second verification data Thus, it is possible to determine the transmission clock frequency setting value at which the image receiving apparatus can accurately receive or decode the image data. Then, only the transmission clock frequency setting value that has been successfully authenticated can be set by the user operation, so that the image data adjusted to the clock frequency setting value set by the user operation is reliably received and decoded by the image receiving device. can do.

In a preferred embodiment, the authenticating means performs authentication of link consistency with the image receiving apparatus using HDCP third authentication.

  In a preferred embodiment, the transmission clock frequency setting value includes at least one of resolution and color depth.

  In a preferred embodiment, the image processing apparatus further includes an acquisition unit configured to acquire a transmission clock frequency setting value that can be handled by the image reception device from the image reception device, and the authentication unit sets a transmission clock frequency that can be handled by the image reception device. The authentication is performed with the image receiving apparatus for a transmission clock frequency setting value that is common to a value and a transmission clock frequency setting value that can be supported by the image transmitting apparatus.

  In this case, the transmission clock frequency setting value that is not supported by the image receiving device (for example, cannot be received, decoded, or displayed) is excluded from the authentication target by the authentication unit. The number can be reduced, and the time until execution of all the authentication processes can be shortened.

  By making it possible to set only the transmission clock frequency setting value that has been successfully authenticated by the user operation, the image data adjusted to the clock frequency setting value selected by the user operation can be reliably received and decoded by the image receiving device. Can do.

  Hereinafter, an image transmission / reception system including an image transmission device (source device, DVD player) and an image reception device (sink device, display device) according to a preferred embodiment of the present invention will be specifically described with reference to the drawings. The present invention is not limited to these embodiments. In this example, image data (hereinafter also referred to as video data) is transmitted and received as HDMI data together with audio data. The image receiving device also includes the meaning of a repeater device (AV amplifier or the like). In this case, the image receiving device is connected in the order of DVD player-AV amplifier-display device.

  FIG. 1 is a principal block diagram showing the configuration of the DVD player 10 and the display device 30. The DVD player 10 and the display device 30 comply with the HDMI standard, for example, and are connected to each other via an HDMI cable.

[Configuration of DVD Player 10]
The DVD player 10 includes a reproduction unit 11, a resolution conversion unit 12, an HDMI transmission unit 13, a system control unit 14, an operation display unit 15, a memory 16, and a connector unit 17.

  The playback unit 11 reads video data recorded on a DVD disc (hereinafter simply referred to as a disc) from the disc, decodes it, and supplies it to the resolution conversion unit 12. Further, the playback unit 11 reads out audio data recorded on the disc from the disc, decodes it, and supplies it to the HDMI transmission unit 13. The reproducing unit 11 includes an optical pickup, a servo circuit, an MPEG decoder, etc. (not shown).

  The resolution conversion unit 12 determines the resolution and color depth of the video data supplied from the reproduction unit 11. In addition, the resolution conversion unit 12 converts the resolution and color depth of the video data into the resolution and color depth set by the user operation according to an instruction from the system control unit 14. The video data whose resolution and color depth are converted by the resolution converter 12 is supplied to the HDMI transmitter 13. Here, the resolution and the color depth are collectively defined as “transmission clock frequency setting value”. This is because the resolution and color depth are set values that affect the transmission clock frequency. For example, the higher the resolution and the deeper the color depth, the higher the transmission clock frequency.

  The HDMI transmission unit 13 converts the video data supplied from the resolution conversion unit 12 and the audio data supplied from the reproduction unit 11 into HDMI standard data (hereinafter referred to as HDMI data) according to an instruction from the system control unit 14. Convert. The HDMI transmission unit 13 encrypts the HDMI data based on the HDCP standard. Also, the HDMI transmission unit 13 reads the authentication information, the repeater bit, Ri ′ in HDCP third authentication, and the like from the register 31a of the display device 30 via the DDC line, and executes HDCP authentication.

  The HDCP authentication includes HDCP first authentication, HDCP second authentication, and HDCP third authentication. The details of each HDCP authentication are described in detail in the High-bandwidth Digital Content Protection Specification Rev. 1.3, and the description is used here, and will be briefly described here.

  In the first HDCP authentication, the HDMI transmission unit 13 reads the authentication information from the register 31a of the connected device (here, the display device 30). If the read authentication information is valid, the HDMI transmitting unit 13 succeeds in authentication with the HDMI receiving unit 31. The HDMI transmitting unit 13 fails to authenticate with the HDMI receiving unit 31 if the read authentication information is invalid or the authentication information cannot be read. The authentication information includes, for example, KSV (key select vector) defined by the HDCP standard.

  Also, the HDMI transmission unit 13 reads the repeater bit from the connected device. The repeater bit indicates whether the device is a repeater device (that is, a device that can transmit HDMI data to another device) or a sink device (that is, a device that cannot transmit HDMI data to another device). Device information, a value of “1” indicates a repeater device, and a value of “0” indicates a sink device.

  The HDCP second authentication is authentication required when the connected device is a repeater device. In HDCP second authentication, when an AV amplifier (not shown) as a repeater device is connected to the DVD player 10 and the display device 30 is connected to the AV amplifier, the authentication information of the AV amplifier and the authentication information of the display device 30 If these are valid, the authentication with the AV amplifier is successful.

  The HDCP third authentication is authentication based on image data, and is executed for each frame number of video data, and is executed in a vertical blanking period between frames of video data. The HDMI transmission unit 13 and the HDMI reception unit 31 calculate new Ki, Mi, and Ri (i represents a frame number). These three values are called “HDCP BlkCipher” and are calculated using a block cipher used in HDCP. Ki and Mi are used to initialize the encryption scheme used for HDCP, and Ri is used to verify the integrity of the link. The HDMI transmitting unit 13 checks Ri ′ received from the HDMI receiving unit 31 and its own Ri, and determines whether the HDMI receiving unit 31 can receive and decode the video data.

  The HDMI transmission unit 13 includes TMDS lines for transmitting and receiving HDMI data (normally, there are a plurality of lines, but only one line is shown in FIG. 1 for simplicity), and hot plugs for determining whether or not there is a connection. To the HDMI receiving unit 31 of the DVD player 10. The HDMI transmission unit 13 is connected to the HDMI reception unit 31 and the PROM 34 of the display device 30 via a DDC line for reading authentication information and EDID.

  The system control unit 14 controls the playback unit 11, the resolution conversion unit 12, the HDMI transmission unit 13, the operation display unit 15, the memory 16, and the like based on the operation program of the DVD player stored in the built-in or connected memory. For example, a microcomputer or a CPU is used. The system control unit 14 executes various processes based on an operation input from the operation display unit 15 or a control signal and data from each unit.

  The system control unit 14 is connected to the system control unit 33 of the display device 30 via the CEC line, and transmits and receives commands and / or data to and from the system control unit 33. Further, the system control unit 14 is connected to the PROM 34 of the display device 30 via the DDC line, and reads the EDID stored in the PROM 34.

  The system control unit 14 actually sets all combinations of resolutions and color depths that the DVD player 10 can support (for example, playback and transmission) to the combinations of resolutions and color depths, and sets the resolutions and By transmitting the video data converted to the color depth to the display device 30, the HDCP third authentication is executed, and the combination of the resolution and the color depth that have been successfully authenticated is registered in the settable value table shown in FIG. A combination of resolution and color depth registered in the settable value table is displayed on the resolution setting screen of FIG. 10 and can be set by a user operation. The combination of resolution and color depth for which authentication has failed is not registered in the settable value table, is not displayed on the resolution setting screen, and cannot be set by a user operation.

  Preferably, the system control unit 14 reads the EDID from the PROM 34 of the display device 30 and reads the resolution and color depth that can be supported (received, decoded, and displayed) included in the EDID. The system control unit 14 extracts a common resolution that can be commonly handled by the DVD player 10 and the display device 30. Similarly, the system control unit 14 extracts a common color depth that can be handled in common by the DVD player 10 and the display device 30. Then, the system control unit 14 actually sets all combinations of the extracted common resolution and common color depth to the combination of the common resolution and common color depth, executes the HDCP third authentication, and succeeds in the authentication. Only combinations of common resolution and common color depth are registered in the settable value table.

  As described above, the system control unit 14 displays only the combination of the resolution and color depth registered in the settable value table on the operation display unit 15 and controls them in a state that can be selected and set by a user operation. As a result, the HDCP third authentication is successful, that is, only the resolution and color depth at which the display device 30 can receive and decode the video data can be set by the user operation. Data can be received and decrypted.

[Configuration of Display Device 30]
The display device 30 includes an HDMI receiving unit 31, a display unit 32, a system control unit 33, a memory (EDID PROM, hereinafter referred to as PROM) 34, an operation unit 35, an audio processing unit 36, and a speaker 37. And a connector portion 38.

  The HDMI receiving unit 31 receives the HDMI data transmitted from the HDMI transmitting unit 13 of the DVD player 10 and decrypts the HDMI data encrypted by HDCP. In addition, the HDMI receiving unit 31 generates original video data from the received HDMI data and supplies it to the display unit 32. In addition, the HDMI receiving unit 31 generates original audio data from the HDMI data and supplies it to the audio processing unit 36.

  The HDMI receiving unit 31 includes a register (storage element) 31a, and authentication information of the display device 30 is registered in advance in the register 31a. In the HDCP first (or second) authentication, the HDMI receiving unit 31 reads out its own authentication information registered in the register 31 a by the HDMI transmitting unit 13 of the DVD player 10.

  The HDMI receiving unit 31 generates Ri ′ for each frame based on the video data during the vertical blanking period of the video data transmitted from the HDMI transmitting unit 13 of the DVD player 10 in the HDCP third authentication, and registers it in the register 31a. To do. Ri ′ registered in the register 31a is read by the HDMI transmission unit 13 of the DVD player 10 every 2 seconds, for example, and compared with Ri, so that the HDMI reception unit 13 can accurately receive and decode the HDMI data. Is confirmed.

  The display unit 32 is supplied with video data from the HDMI receiving unit 31 and displays video based on the video data, and is, for example, an LCD or a CRT.

  The audio processing unit 36 performs processing such as signal processing, amplification processing, and D / A conversion on the audio data supplied from the HDMI receiving unit 31 and supplies the processed audio data to the speaker 37.

  The system control unit 33 controls the HDMI receiving unit 31, the display unit 32, the PROM 34, the audio processing unit 36, and the like based on an operation program of the display device stored in a built-in or connected memory. A microcomputer or a CPU. The system control unit 33 executes various processes based on an operation input from the operation unit 35 or a control signal and data from each unit.

[Operation]
FIG. 2 is a flowchart for explaining the processing of the DVD player 10. The system control unit 14 sets n (initial value) indicating n indicating the resolution number to be subjected to HDCP third authentication (S1). Similarly, the control unit 14 sets m (0) (initial value), which indicates the color depth number for which HDCP third authentication is executed (S1).

  The system control unit 14 determines whether EDID can be obtained from the connected display device 30 (S2). If the EDID can be acquired (YES in S2), the system control unit 14 acquires the EDID from the PROM 34 of the display device 30 (S3). The system control unit 14 reads the resolution B that can be supported by the display device 30 included in the EDID, and stores it in the memory as shown in FIG. In this example, the resolution B that can be supported by the display device 30 is 480i, 480p, 1080i, 720p, and 1080p. Similarly, the system control unit 14 reads the color depth b that can be supported by the display device 30 included in the EDID, and stores it in the memory as shown in FIG. In this example, the color depth b that can be supported by the display device 30 is 24 bits, 30 bits, and 36 bits.

  On the other hand, if the EDID cannot be acquired (NO in S2), the system control unit 14 estimates the resolution A (see FIG. 5) that the DVD player 10 can handle as the resolution B that the display device 30 can handle (see FIG. 5). S4). Similarly, the system control unit 14 estimates the color depth a (see FIG. 6) that can be handled by the DVD player 10 as the color depth b that can be handled by the display device 30 (S4).

  In this example, the resolution A that can be supported by the DVD player 10 is 480p, 720p, 1080i, 1080p, 1440 * 480p. The color depth a that can be supported by the DVD player 10 is 24 bits, 30 bits, 36 bits, and 48 bits.

  The system control unit 14 monitors whether an instruction to shift to the resolution (and color depth) setting screen is input by a user operation (S5). When input (YES in S5), the system control unit 14 compares the resolution A that can be handled by the DVD player 10 with the resolution B that the display device 30 can handle, and the common resolution C is shown in FIG. (S6). The common resolution is represented by Cn (n is an integer starting from 0), and in this example, 480p (C0), 720p (C1), 1080i (C2), and 1080p (C3).

  The system control unit 14 compares the color depth a that can be handled by the DVD player 10 with the color depth b that can be handled by the display device 30, and stores the common color depth c in the memory as shown in FIG. S7). The common color depth is expressed in cm (m is an integer starting from 0), and in this example, it is 24 bits (c0), 30 bits (c1), and 36 bits (c2).

  Subsequently, in response to the instruction from the system control unit 14, the HDMI transmission unit 13 executes the first HDCP authentication with the HDMI reception unit 31 of the display device 30 (S8). Specifically, the HDMI transmission unit 13 acquires authentication information of the display device 30 from the register 31 a of the HDMI reception unit 31. Then, the HDMI transmission unit 13 determines whether or not the acquired authentication information is valid (S9). When an AV amplifier is connected between the DVD player 10 and the display device 30, the HDMI transmission unit 13 executes HDCP first authentication and HDCP second authentication.

  If the acquired authentication information is not valid (NO in S9), the HDCP authentication fails and the process ends. On the other hand, if the acquired authentication information is valid (YES in S9), since the HDCP authentication is successful, the HDMI transmission unit 13 converts the resolution conversion unit 12 into the common resolution Cn in FIG. 7 and the common color depth cm in FIG. The HDMI data including the video data converted by the above is transmitted to the display device 30 (S10). Here, since n = 0 and m = 0 are set in S1, video data having a common resolution of 480p (C0) and a common color depth of 24 bits (c0) is transmitted to the display device 30.

  The HDMI transmission unit 13 executes HDCP third authentication with the HDMI reception unit 31 of the display device 30 (S11). Specifically, upon receiving video data having a common resolution of 480p (C0) and a common color depth of 24 bits (c0), the HDMI receiving unit 31 of the display device 30 decodes the HDMI data and then performs a vertical blanking period of the video data. , Ri ′ is generated for each frame based on the video data and registered in the register 31a. On the other hand, the HDMI transmitting unit 13 of the DVD player 10 generates Ri based on the transmitted video data, acquires Ri ′ from the register 31a, and determines whether Ri = Ri ′, for example, for 2 seconds. A determination is made about five times at intervals (S12).

  If Ri = Ri ′ can be confirmed five times continuously (YES in S12), the HDMI receiving unit 31 can correctly receive and decode the video data converted by the common resolution Cn and the common color depth cm. Therefore, the system control unit 14 registers the common resolution Cn and the common color depth cm as combinations that can be set by a user operation in the settable value table shown in FIG. 9 (S13). Then, it progresses to S14.

  On the other hand, if the number of times Ri = Ri ′ can be confirmed is less than 5 (NO in S12), the HDMI receiving unit 31 accurately receives and decodes the video data converted by the common resolution Cn and the common color depth cm. Therefore, the system control unit 14 does not register the common resolution Cn and the common color depth cm as combinations that can be set by the user operation in the settable value table shown in FIG. Proceed to

  In S14 to S17, by incrementing the common resolution number n and the common color depth number m and returning to S8, all combinations of the common resolution Cn in FIG. 7 and the common color depth cm in FIG. All the combinations of the common resolution Cn and the common color depth cm in which the processes of S8 to S13 have been executed and the HDCP third authentication has succeeded (that is, the HDMI receiving unit 31 has correctly received and decoded the video data) Extracted and registered in the settable value table of FIG.

  Specifically, it is determined whether or not m has reached the maximum value Dmax (3 in FIG. 7) of the common resolution number in S14. If not (NO in S14), m is incremented (S15). , Return to S8. On the other hand, if reached (YES in S14), it is determined in S16 whether n has reached the maximum value Rmax of the common color depth number (2 in FIG. 8). If not reached (NO in S16), n is set. Increment (S17) and return to S8. On the other hand, if it has reached (YES in S16), the process is terminated.

  Through the above processing, the combination of the common resolution Cn and the common color depth cm that the HDMI receiving unit 31 can correctly receive and decode the video data can be registered in the settable value table of FIG. In the example of FIG. 9, 480p / 24bit, 480p / 30bit, 480p / 36bit, 720p / 24bit, 720p / 30bit, 1080i / 24bit, 1080p / 24bit are registered in the settable value table.

  Thereafter, the system control unit 14 displays the combination of the common resolution and the common color depth registered in the settable value table on the resolution setting screen shown in FIG. 10, and the combination of the desired resolution and color depth by the user operation. Select. The system control unit 14 controls the resolution conversion unit 12 to convert the video data to the selected resolution and color depth. Thereby, the HDMI transmission unit 13 can transmit the video data converted into the set resolution and color depth to the HDMI reception unit 31. Since the set resolution and color depth are a combination of the resolution and the color depth in which the HDCP third authentication has succeeded in advance (that is, the HDMI receiving unit 31 has correctly received and decoded the video data). The HDMI receiving unit 31 can accurately receive and decode video data.

  In the process of FIG. 2, the common resolution and the resolution and the color depth that can be supported by the display device 30 included in the EDID of the display device 30 and the image and the color depth that can be handled by the DVD player 10 Although the settable value is extracted from the common color depth, the settable value may be extracted from only possible image degrees and color depths that can be handled by the DVD player 10. In this case, the processing of S2 to S4, S6, and S7 in FIG.

  In the process of FIG. 2, the HDCP third authentication is executed for the combination of the resolution and the color depth, and the combination of the resolution and the color depth is registered in the settable value table, but only one of the resolution and the color depth is registered. In the case of a DVD player that can only be set by a user operation, the HDCP third authentication may be executed only with a compatible resolution, and only the resolution may be registered in the settable value list. 3 authentication may be executed, and only the color depth may be registered in the settable value list.

  As mentioned above, although preferable embodiment of this invention was described, this invention is not limited to these embodiment. For example, the authentication information, the repeater bit, and Ri ′ may not be registered in the register but may be registered in a memory or the like. Further, the HDMI transmitting unit acquires authentication information from the HDMI receiving unit and executes authentication processing. However, the HDMI transmitting unit and the HDMI receiving unit may exchange authentication information with each other and execute authentication processing. . The authentication process may be executed by the system control units. The same applies when one or more AV amplifiers are connected between the DVD player and the display device. In this case, the AV amplifier performs the operation of the display device. The image transmission apparatus is not limited to a DVD player, and may be a BD player, a set top box, an IP terminal, or the like. Further, the program may be provided in the form of a program for causing a computer to execute the above operations of the DVD player and the display device, and a recording medium on which the program is recorded. Further, a program for only a part of the above-described operation of the DVD player or the display device may be provided to the DVD player or the display device in the form of firmware update. Furthermore, it may be provided in the form of an electronic component such as an HDMI transmission unit, an HDMI reception unit, or a system control unit that stores a program for only a part of the above-described operation of the DVD player or display device.

  The present invention can be suitably employed in DVD players and display devices.

1 is a block diagram showing a configuration of a DVD player 10 and a display device 30 according to a preferred embodiment of the present invention. 4 is a flowchart showing processing of the DVD player 10. FIG. 4 is a diagram illustrating a corresponding resolution of the display device 30. FIG. 6 is a diagram illustrating a corresponding color depth of the display device 30. FIG. 4 is a diagram showing the corresponding resolution of the DVD player 10. FIG. 4 is a diagram illustrating the corresponding color depth of the DVD player 10. It is a figure which shows the common resolution which both a DVD player and the display apparatus 30 can respond | correspond. It is a figure which shows the common color depth which a DVD player and the display apparatus 30 can respond | correspond together. It is a figure which shows a settable value table. It is a figure which shows the resolution (and color depth) setting screen.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 DVD player 11 Reproduction | regeneration part 12 Resolution conversion part 13 HDMI transmission part 14 System control part 30 Display apparatus 31 HDMI reception part 31a Register 33 System control part

Claims (5)

Connection means for connecting to the image receiving device;
Transmitting means for transmitting image data to the image receiving device;
Verification data generating means for generating first verification data for verifying link consistency based on image data adjusted to each transmission clock frequency setting value for a plurality of transmission clock frequency setting values ;
Each of the image data in which the first verification data is generated is transmitted to the image reception device by the transmission unit, and second verification data for verifying link consistency is generated by the image reception device, Verification data reading means for reading out the second verification data from the image receiving device each time two verification data are generated;
Authentication for performing authentication of link consistency with the image receiving device by comparing the second verification data read by the verification data reading means with the first verification data generated by the verification data generation means Means,
A setting enabling means for enabling setting of the transmission clock frequency set value that has been successfully authenticated by authentication by the authenticating means, and making it impossible to set the clock frequency setting value that has failed for authentication by user operation; An image transmission device comprising: The image transmitting apparatus according to claim 1, wherein the authentication unit performs authentication of link consistency with the image receiving apparatus using HDCP third authentication.   The image transmission device according to claim 1, wherein the transmission clock frequency setting value includes at least one of resolution and color depth. An acquisition means for acquiring a transmission clock frequency setting value that can be supported by the image reception device from the image reception device;
The authentication means receives the authentication for the transmission clock frequency setting value common to the transmission clock frequency setting value that can be supported by the image receiving apparatus and the transmission clock frequency setting value that can be supported by the image transmitting apparatus. The image transmission apparatus according to claim 1, wherein the image transmission apparatus is executed with the apparatus. A connection step for connecting to the image receiving device;
A transmitting step of transmitting image data to the image receiving device;
For a plurality of transmission clock frequency setting values, a verification data generation step for generating first verification data for verifying link consistency based on image data adjusted to each transmission clock frequency setting value;
Each of the image data in which the first verification data is generated is transmitted to the image receiving device in the transmitting step, and second verification data for verifying link integrity is generated in the image receiving device, A verification data reading step of reading out the second verification data from the image receiving device each time two verification data are generated;
Authentication for executing authentication of link consistency with the image receiving apparatus by comparing the second verification data read in the verification data reading step with the first verification data generated in the verification data generation step Steps,
A setting enabling step for enabling setting of the transmission clock frequency setting value that has been successfully authenticated by authentication by the authentication step, and setting the clock frequency setting value that has failed authentication not possible by user operation; An operation program for an image transmission apparatus that causes a computer to execute

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