JP4899412B2 - Image display system and method - Google Patents

Description

  The present invention relates to an HDR (High Dynamic Range) display technology that uses multi-bit high-precision data and displays an image that is close to the actual display on a display, and transmits image data corresponding to the HDR format to an HDR display device to increase the image quality. The present invention relates to an image display system and method for displaying an image with high brightness / high contrast.

In recent years, in the field of computer graphics, HDR rendering technology has been developed, and the calculation of the displayed color is not performed on each of the 8 colors (16.77 million colors) of the three primary colors R (red), G (green), and B (blue). High-precision color calculation is performed using multiple bits, and an image close to the state actually seen is generated.
In addition, as a display for HDR display, a color modulation optical element that modulates the luminance of the three primary colors of incident light according to image data, and the luminance of all wavelengths of light incident from the RGB color modulation optical elements are modulated. A two-modulation projection display device has been developed in which a luminance modulation optical element is optically arranged in series and projected onto a screen.

In addition to the increase in the number of bits of each image data, as the display resolution of the image display device (display device) increases, the dot clock (or also expressed as a pixel clock) for sending the image data to be displayed is high speed. Is necessary.
For example, as a dot clock, 66 MHz is required for XGA (1024 × 768), 110 MHz is required for SXGA (1280 × 1024), 165 MHz is required for UXGA (1600 × 1200), and QXGA (2048 × 1536). ) Requires 264 MHz.
The

For this reason, in the DVI (Digital Visual Interface) standard used in personal computers and the like, a specification called two links, each called a dual link, is handled as one interface.
When the RGB signal is in the RGB 8-bit pixel data format, the above-described dual link is used to divide the display screen into two, each corresponding to an interface, and substantially double the resolution data is transmitted. In addition, instead of increasing the resolution, the number of gradations of the data of each pixel can be expressed as pixel data of 16 bits for each RGB (see, for example, Patent Document 1).

FIG. 4 shows a configuration of an image processing apparatus that transmits HDR format image data (R, G, and B, respectively) to a normal display through a dual link.
Hereinafter, as the HDR format, for example, a format of image data (for each of R, G, and B) represented by a 32-bit floating point and having a dynamic range of a high luminance value is shown.
The image generation unit 101 generates the image data using, for example, HDR rendering technology.
The conversion processing unit 102 reads the image data, divides the dynamic range having a wide luminance value into blocks by tone mapping, and supports a normal image display device, that is, a display that displays LDR (Low Dynamic Range) format image data. Thus, every R, G, B is converted into 8-bit gradation data.

The video division processing unit 103 divides the display image into two parts for each field, for example, an upper region and a lower region, and converts the gradation data of the pixels in the upper region to the data transmission unit 104 and the gradation data in the lower region. The data is output to the data transmission unit 105.
Thereby, the data transmission unit 104 outputs the gradation data D1 to the signal line 108 via the output unit 106, and the data transmission unit 105 outputs the gradation data D2 to the signal line 109 via the output unit 7. Here, the signal line 108 and the signal line 109 constitute a dual link.

On the other hand, the image display device shown in FIG. 5 is a dual link display. The data receiving unit 113 inputs gradation data D1 from the signal line 108 via the input unit 111, and the data receiving unit 114 inputs gradation data D2 from the signal line 109 via the input unit 112.
The image composition processing unit 115 synthesizes the gradation data 1 and the gradation data 2, reproduces image data in units of frames, and sequentially outputs the image data to the display control unit 116.
Then, the display control unit 116 causes the display device 117 to display an image corresponding to the input image data.
JP 2002-156955 A

However, even if each of RGB is transmitted with a 16-bit gradation using the dual link as described above, there is a problem that the luminance value and the contrast of the image cannot be expressed sufficiently when displaying in the HDR format.
In order to use the above-described dual link, it is necessary to implement EDID (Extended Display Identification Data) in accordance with the DVI standard. The DDC1 (Display Data Channel version 1) method for sending the EDID information from the image display device side to the image processing device side is simple and easy to implement, but in DVI, DDC2B (Display Data Channel Bi-directional) Must be implemented.

The DDC1 system is a bidirectional data channel based on the I2C bus protocol which is a two-wire serial interface, and the image processing apparatus can request EDID information from the monitor via the DDC2B channel.
However, the mounting of the DDC 2B requires complicated arithmetic processing in both the image processing apparatus and the image display apparatus, and it is necessary to mount a CPU and create a processing program. In order to transmit the image signal from the image processing apparatus to the image display apparatus with 16 bits, a considerable development man-hour is required, and the manufacturing cost increases.

  The present invention has been made in view of such circumstances, and easily transfers image data including luminance value and contrast information capable of HDR image display from the image processing apparatus to the image display apparatus. It is an object of the present invention to provide an image display system and method for displaying an image in HDR format.

  An image display system of the present invention is an image display system that includes an image processing device that outputs image data in HDR format and an image display device that displays the image data in HDR format. A conversion processing unit that performs tone mapping to generate gradation data, a correction data generation unit that generates correction data that corrects the gradation data and returns the image data to HDR format, and the gradation data and the correction data And an output control unit that outputs the image data to different signal lines, and the image display device reproduces image data from the input gradation data and correction data, and the image data And an image display unit to be displayed on the display device. According to this, the image processing system of the present invention uses the gradation data for each RGB that has been used conventionally, and the gradation data is reproduced as original image data using the correction data on the image display device side. Therefore, it is possible to display an HDR format image on the display unit.

The image display system of the present invention is characterized in that the correction data generation unit divides image data by gradation data and outputs the division result as correction data.
The image display system of the present invention is characterized in that the correction data is in a floating point data format.
According to this, the image display system of the present invention can transmit image data having a high dynamic range width with respect to the luminance value by a signal line with a small number of bits.

  In the image display system of the present invention, when the signal line for transmitting the correction data is 8 bits, the mantissa part of the correction data is 5 bits, the exponent part is 3 bits, and an offset of −10 is given to the exponent part. It is characterized by. According to this, the image display system of the present invention can express the numerical range widely with a small number of bits by the mantissa part and the exponent part, and image data (gradation degree data and correction data) having a high luminance dynamic range width. Can be sent.

  The image display system of the present invention is characterized in that the output control unit synchronizes and outputs a vertical synchronizing signal and a horizontal synchronizing signal of the gradation data and correction data, respectively. According to this, it is possible to detect the reception of the gradation data and the correction data by detecting at the same timing, and in the receiving image display device side, the data is in the HDR format or the conventional format only with the gradation data. It is possible to perform a display corresponding to the data format.

  The image display system of the present invention has a synchronization detection unit that detects whether or not the input gradation data and correction data are synchronized, and when detecting that the synchronization detection unit is synchronized, When the image data reproducing unit reproduces the image data based on the gradation data and the correction data, and detects that the data is not synchronized, the image display unit displays the image using only the gradation data. Features. According to this, in the image display system of the present invention, when the data input from the two signal lines are synchronized, the HDR format data (gradation degree data and correction data) is input as HDR. If the image data of the format is processed and is not synchronized, it is determined that only normal gradation data is input, and one of the signal lines (the gradation data is set to be transmitted) Since the image data is displayed by reproducing the data input from the device, unnecessary images are not displayed on the display device, and the display device is prevented from being deteriorated.

  An image display system of the present invention is an image display method in which an image processing apparatus outputs image data in HDR format, and the image display apparatus inputs the image data and displays it in HDR format. An image generation process in which the image data is generated in HDR format, a conversion processing unit in which the image data is tone-mapped to generate gradation data, and a correction data generation unit corrects the gradation data. A correction data generation process for generating correction data to be returned to HDR format image data, and an output control process in which the output unit outputs the gradation data and the correction data to different signal lines. In the apparatus, the image data reproducing unit reproduces image data from the gradation data and the correction data inputted thereto, and the image display unit displays the image Characterized in that it has an image display step of displaying the over data to the display device.

An image processing apparatus according to the present invention is an image processing apparatus that generates HDR format image data and transmits the image data to an image display apparatus that displays the HDR format. The image processing apparatus generates HDR format image data. An image generation unit that performs tone mapping of the image data to generate gradation data, and a correction data generation unit that generates correction data that corrects the gradation data and returns it to HDR-format image data And an output control unit for outputting the gradation data and the correction data to different signal lines.
The image display apparatus of the present invention is an image display apparatus that inputs image data in HDR format composed of gradation degree data and correction data, and displays the image data in HDR format. An image data reproduction unit that reproduces image data from the data and an image display unit that displays the image data on a display device are provided.

Hereinafter, an image display system according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a configuration example of an image display system according to the embodiment.
One embodiment includes an image processing device 1 that outputs image data in HDR format, and an image display device 2 that displays input image data in HDR format.
The image processing apparatus 1 performs tone mapping of the image data with an image generation unit 11 that generates HDR format image data (which may be a CAD connected to the outside without providing this configuration), and obtains gradation data. The conversion processing unit 12 to be generated, the correction data generation unit 13 that generates correction data that corrects the gradation data and restores the image data in the HDR format, and the output that outputs the gradation data and the correction data to different signal lines. And a control unit 14.
In addition, the image display device 2 includes an image data reproduction unit 26 that reproduces image data from input gradation data and correction data, and an image display unit that displays the image data on the display unit 29 (the signal processing unit 27 and the display unit). And a control unit 28).

Moreover, the output control part 14, the data transmission part 15, the data transmission part 16, the output part 17, and the output communication part 18 are comprised by the hardware as an interface board, for example.
The output control unit 14 distributes and outputs the gradation data and the correction data to the data transmission unit 15 and the data transmission unit 16, respectively.
The data transmission unit 15 outputs the input gradation data to the signal line 31 via the output unit 17.
The data transmission unit 16 outputs the input gradation data to the signal line 32 via the output unit 18.

Here, the video interface used in a personal computer or the like is a non-interlace method, unlike the interlaced scanning which is a conventional television video interface. That is, from the image processing apparatus 1 side that transmits the image signal, the pixel data constituting each line is sequentially transmitted from the uppermost line to the lowermost line of the display screen of the display unit 29 and from the left end to the right end. .
In the present invention, the display screen is displayed in the timing detection for detecting whether or not the data is reproduced in the HDR format from the gradation data and the correction data received on the image display device 2 side. The vertical sync signal (VSYNC) and horizontal sync signal (HSYNC) used in the above are used. When the display control unit 28 displays on the display unit 29, the vertical synchronization signal is used to determine the top line, and the horizontal synchronization signal is used to determine the position of the display pixel pixel data of each line.

When image data (high resolution video) is transmitted from one image processing device to two different image display devices using different signal lines (links), the receiving image display devices are independent of each other. Since image data is written to the display device, it is not necessary to synchronize the image data flowing through the two signal lines. That is, the transmission timings of the vertical synchronization signal and the horizontal synchronization signal may be different, and it is not necessary that the position at which each transmission pixel data is displayed on the display unit corresponds.
Therefore, when image data is transmitted from one image processing device to two different image display devices, the image data that normally flows through the two signal lines are not synchronized and each is sent at an independent timing. Has been.

On the other hand, as in the embodiment of the present invention, when data is sent from one image processing device to one image display device using two signal lines, the image display device which is the image data receiving side If the buffer has a buffer memory, there is no problem even if the timing of sending the vertical synchronization signal and the horizontal synchronization signal of the two signals is different when the gradation data and the correction data are output to different signal lines.
However, as in the embodiment of the present invention, in order to reduce the cost of the image display device used by the viewer, when the buffer memory is not provided, the image data is sequentially reproduced from the input gradation data and correction data. In order to display on the display unit 29, it is necessary to synchronize the vertical synchronization signal and the horizontal synchronization signal transmitted to the two different signal lines 31 and 32 and transmit the gradation data and the correction data.

Next, the operation of the image display system according to the embodiment will be described with reference to FIGS. 1 and 2.
The user generates an HDR image represented by HDR format image data extracted from a photograph or video using an HDR rendering technique in the image generation unit 11 (for example, an HDR-compatible CAD system).
Then, the case where the generated HDR image is transferred to the image display device 2 and the HDR image is displayed on the display unit 29 will be described.
The image generation unit 11 sequentially outputs the image data in the HDR image to the conversion processing unit 12 in the order of display on the display unit 29.

Next, the conversion processing unit 12 converts the input image data into, for example, 8-bit gradation data for each of R, G, and B by tone mapping.
Here, the image data that normally flows through the video interface is inversely γ-converted with a predetermined γ value (γ0.45) corresponding to the characteristics of the display to be displayed (γ characteristics, γ2.2), and is absolutely It is not a typical brightness but a relative brightness. For this reason, the HDR image displayed on the display unit 29 may be in an image state different from the intention of the created user.
Therefore, in order to avoid the above-described problem, it is necessary to transmit image data of absolute luminance values in the HDR format to an HDR compatible image display device having a wide dynamic value dynamic range. For example, the transmission may be performed in a 32-bit floating point display. However, when connecting to a normal monitor, only the gradation data is often required, and this embodiment uses the gradation data from the viewpoint of compatibility. It is set as the structure which can supply only.

Therefore, the correction data generation unit 13 divides the image data (R, G, B) for each of R, G, B by the gradation data (R, G, B) obtained by the conversion processing unit 12. Then, the division result is output as generated correction data (R, G, B).
The correspondence between the correction data generated here and gradation data is a contrast ratio of at least 100,000 as a practical value as image data in HDR format, a minimum luminance value of about 0.001 cd / m ² , and a maximum. When a luminance value of about several hundred cd / m ² is realized using two 8-bit signal lines, the following data structure is obtained.
If the number of bits in the exponent part is reduced, the dynamic range of the luminance value is narrowed. Therefore, the exponent part h is 3 bits, the mantissa part n is 5 bits, an offset of “−10” is given to the exponent part, and “n × 2 ^(h-10) "floating point format data structure. Therefore, when the gradation data m is 8 bits, the image data is multiplied by the gradation data and the correction data, and the following equation (1) is obtained.
m × n × 2 ^(h-10) (1)

For example, when m = 1, n = 1, and h = 1,
1 × 1 × 2 ⁽⁻¹⁰⁾ = 0.000977 cd / m ²
It becomes.
Further, when m = 255, n = 31, and h = 7 as the maximum values,
255 × 31 × 2 (7−10) = 988.125 cd / m ²
It becomes.
The contrast ratio between the maximum value and the minimum value is about 10 ⁶ , which satisfies the characteristics as image data in the HDR format.

Then, the correction data generation unit 13 outputs the gradation data and the generated correction data to the output control unit 14.
The output control unit 14 distributes the input gradation data and correction data, for example, outputs gradation data to the data transmission unit 15 and distributes correction data to the data transmission unit 16 for output.
Here, as a result, two data, that is, 8-bit gradation data in a conventional format obtained by performing tone mapping and correction data are transmitted to one HDR-format image data (pixel data).

The output control unit 14 outputs the two data of the gradation data and the correction data to the data transmission unit 15 and the data transmission unit 16 in synchronization (synchronization).
Synchronizing here means that the horizontal sync signal (HSYNC) and the vertical sync signal (VSYNC) are sent between the data transmitter 15 and the data transmitter 16 by the same dot clock synchronized with the output controller 14. This means that transmission is performed at the same timing, and corresponding gradation data and correction data are transmitted at the same timing.

Then, each of the data transmission unit 15 and the data transmission unit 16 sends the synchronized gradation data and correction data to the signal line 31 via the output unit 17 and to the signal line 32 via the output unit 18, respectively. Output separately.
Next, the data receiving unit 23 inputs the gradation data from the signal line 31 via the input unit 21 and outputs it to the synchronization detection unit 25.
Similarly, the data reception unit 24 inputs correction data from the signal line 32 via the input unit 22 and outputs the correction data to the synchronization detection unit 25.

  The synchronization detection unit 25 detects the synchronization state of the dot clock between the data reception unit 23 and the data reception unit 24. In other words, the synchronization detection unit 25 performs the synchronization state of the dot clock by, for example, detecting a difference in clock frequency. As an example of the difference detection, as shown in FIG. 3A, when the horizontal synchronization signal is detected with reference to the dot clock, the internal counter is reset and the next time the horizontal synchronization signal is detected. The dot clock is counted, and the count values of the internal counter corresponding to the data receiving unit 23 (corresponding to the gradation data) and the internal counter corresponding to the data receiving unit 24 (corresponding to the correction data) are compared, If the count values of the two internal counters are the same, synchronization is achieved, and if they are different, synchronization is not achieved. This detection circuit can be composed of very few circuits.

Next, the synchronization detection unit 25 detects the synchronization state of the vertical synchronization signal and the horizontal synchronization signal of the gradation data and the correction data, respectively. Although there are various methods for detecting this synchronization state, as shown in FIGS. 3B and 3C, the pulse width W1 of the horizontal synchronization signal S1 corresponding to the gradation data and the horizontal synchronization corresponding to the correction data. The pulse width W2 of the signal S2 is measured. Then, the synchronization detection unit 25 creates a logical product waveform of the horizontal synchronization signal S1 and the horizontal synchronization signal S2, and measures the pulse width Wa of the logical product waveform.
Next, the synchronization detection unit 25 compares the pulse widths W1, W2, and Wa. When W1 = W2 = Wa and when it is detected that all of the pulse widths W1, W2, and Wa are equal, FIG. As shown in FIG. 5, it is detected that the horizontal synchronization signal S1 and the horizontal synchronization signal S2 are synchronized.

On the other hand, the synchronization detection unit 25 compares the pulse widths W1, W2, and Wa, and if W1 = W2 ≠ Wa and it is detected that the pulse widths W1, W2 and the pulse width Wa are different, FIG. ), Since W1 = W2 = Wa is not satisfied, it is detected that the horizontal synchronization signal S1 and the horizontal synchronization signal S2 are not synchronized. That is, FIG. 3B shows an example in which the transmission timings of the horizontal synchronization signal S1 and the horizontal synchronization signal S2 are different.
Further, as can be seen from FIGS. 3B and 3C, any one of the pulse width of the horizontal synchronizing signal S1 and the horizontal synchronizing signal S2, the transmission timing, and the frequency of the synchronizing signal (that is, the frequency of the dot clock) can be obtained. If they are different, the pulse width W1 = W2 = Wa cannot be satisfied.

When the synchronization detection unit 25 detects that the horizontal synchronization signal S1, the horizontal synchronization signal S2, the vertical synchronization signal, the gradation data, and the correction data are not synchronized, the gradation data is directly transmitted to the image data generation unit 26. The correction data is output as 1, that is, only normal gradation data is input.
As a result, the image data reproducing unit 26 outputs only the gradation data to the signal processing unit 27 in order to multiply the gradation data by 1 of the correction data according to the equation (1).
Further, the synchronization detection unit 25 may invalidate reception of the correction data and transmit control information indicating invalidity to the image data reproduction unit 26. In this case, when a control signal indicating that the correction data is invalid is input, the image data reproduction unit 26 outputs the input gradation data to the signal processing unit 27 as it is without performing any processing. .

On the other hand, when the synchronization detection unit 25 detects that the horizontal synchronization signal S1 and the horizontal synchronization signal S2, the vertical synchronization signal, the gradation data, and the correction data are synchronized, the gradation data and the correction data are transferred to the image data reproduction unit. 26.
When the gradation data and the correction data are input, the image data reproduction unit 26 multiplies the input gradation data and the correction data for each of R, G, and B in units of pixels according to equation (1). The HDR image data is reproduced, and the reproduced image data is output to the signal processing unit 27.

Next, the signal processing unit 27 converts the display data into the format displayed on the display unit 29 and outputs the obtained display data to the display control unit 28.
The display control unit 28 performs display processing on the display unit 29 based on the input display data, and displays an HDR format image having a dynamic range with a high luminance value on the display unit 29.
For example, when the image display device 2 is the two-modulation projection type display device (two-modulation projector) described in the conventional example, an optical signal with uniform polarization is separated into R, G, and B, and R, G, B Modulated by a first modulation light valve that performs color modulation prepared every time, synthesizes the optical signal after color modulation, performs luminance modulation in the entire wavelength region of the combined optical signal by the second modulation light valve, Display processing for projecting the signal light after color modulation and luminance modulation from the projection lens onto the display unit 29 (screen) is performed.

Here, the signal processing unit 27 performs first modulation control for controlling the first modulation light valve from sequentially input HDR format image data (RGB signals), that is, R, G, and B data for each pixel. A signal and a second modulation control signal for controlling the second modulation light valve that modulates the entire wavelength range are generated.
The display control unit 28 controls the first modulation light valve by the first modulation control signal, performs color modulation of the optical signal, and controls the second modulation light valve by the second modulation control signal, The luminance of the optical signal synthesized after emission from the first modulation light valve is modulated, and the image corresponding to the luminance information of each of R, G, and B of the image data is applied to the screen of the display unit 29 via the projection lens. Display.

  In addition, the image generation unit 11, the conversion processing unit 12, the correction data generation unit 13, and the output control unit 14 in the image processing apparatus 1 in FIG. 1, and the image data reproduction unit 26, the signal processing unit 27, and the display control in the image display apparatus 2 are illustrated. A program for realizing the function with the unit 28 is recorded on a computer-readable recording medium, and the program recorded on the recording medium is read into a computer system and executed to execute gradation data and correction from the image data. Data generation and image data reproduction processing from gradation data and correction data may be performed. Here, the “computer system” includes an OS and hardware such as peripheral devices. The “computer system” includes a WWW system having a homepage providing environment (or display environment). The “computer-readable recording medium” refers to a storage device such as a flexible medium, a magneto-optical disk, a portable medium such as a ROM and a CD-ROM, and a hard disk incorporated in a computer system. Further, the “computer-readable recording medium” refers to a volatile memory (RAM) in a computer system that becomes a server or a client when a program is transmitted via a network such as the Internet or a communication line such as a telephone line. In addition, those holding programs for a certain period of time are also included.

  The program may be transmitted from a computer system storing the program in a storage device or the like to another computer system via a transmission medium or by a transmission wave in the transmission medium. Here, the “transmission medium” for transmitting the program refers to a medium having a function of transmitting information, such as a network (communication network) such as the Internet or a communication line (communication line) such as a telephone line. The program may be for realizing a part of the functions described above. Furthermore, what can implement | achieve the function mentioned above in combination with the program already recorded on the computer system, and what is called a difference file (difference program) may be sufficient.

It is a block diagram which shows the structural example of the image processing apparatus 1 in the image display system by one Embodiment of this invention. It is a block diagram which shows the structural example of the image display apparatus 2 in the image display system by one Embodiment of this invention. It is a timing chart explaining the operation example of the synchronous detection part 25 in FIG. 2 of one Embodiment. It is a block diagram which shows the structure of the image processing apparatus in the conventional image display system. It is a block diagram which shows the structure of the image display apparatus in the conventional image display system.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Image processing apparatus 2 ... Image display apparatus 11 ... Image generation part 12 ... Correction data generation part 14 ... Output control part 15, 16 ... Data transmission part 17, 18 ... Output part 21, 22 ... Input part 23, 24 ... Data Receiving unit 25 ... synchronization detecting unit 26 ... image data reproducing unit 27 ... signal processing unit 28 ... display control unit 29 ... display unit

Claims (6)

An image display system configured to include an image processing device that outputs image data in HDR format and an image display device that displays the image data in HDR format,
The image processing device
A conversion processing unit that performs tone mapping on the image data to generate gradation data;
A correction data generation unit that corrects the gradation data and generates correction data that returns the image data in HDR format;
An output control unit that outputs the gradation data and the correction data to different signal lines;
The image display device
An image data reproduction unit for reproducing image data from the input gradation data and correction data;
An image display system comprising: an image display unit configured to display the image data on a display device.   The image display system according to claim 1, wherein the correction data generation unit divides the image data by gradation data and outputs the division result as correction data.   3. The image display system according to claim 2, wherein the correction data is in a floating point data format.   3. When the signal line for transmitting the correction data is 8 bits, the mantissa part of the correction data is 5 bits, the exponent part is 3 bits, and an offset of −10 is given to the exponent part. The image display system according to claim 3.   5. The image display system according to claim 1, wherein the output control unit synchronizes and outputs a vertical synchronization signal and a horizontal synchronization signal of each of the gradation data and the correction data. 6. An image display method in which an image processing device outputs image data in HDR format, and an image display device inputs the image data and displays it in HDR format.
In the image processing apparatus,
An image generation process in which the image generation unit generates image data in HDR format;
A conversion process in which the conversion processing unit performs tone mapping on the image data to generate gradation data;
A correction data generation process in which a correction data generation unit generates correction data for correcting the gradation data and returning it to image data in HDR format;
An output unit having an output control process for outputting the gradation data and the correction data to different signal lines;
In an image display device,
An image data reproduction process for reproducing image data from the gradation data and the correction data input by the image data reproduction unit;
An image display method, wherein the image display unit includes an image display process for displaying the image data on a display device.

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