CN109982007B - Format conversion circuit applied to set top box and related method - Google Patents
Format conversion circuit applied to set top box and related method Download PDFInfo
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- CN109982007B CN109982007B CN201711441310.7A CN201711441310A CN109982007B CN 109982007 B CN109982007 B CN 109982007B CN 201711441310 A CN201711441310 A CN 201711441310A CN 109982007 B CN109982007 B CN 109982007B
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N21/00—Selective content distribution, e.g. interactive television or video on demand [VOD]
- H04N21/40—Client devices specifically adapted for the reception of or interaction with content, e.g. set-top-box [STB]; Operations thereof
- H04N21/41—Structure of client; Structure of client peripherals
- H04N21/4104—Peripherals receiving signals from specially adapted client devices
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N21/00—Selective content distribution, e.g. interactive television or video on demand [VOD]
- H04N21/40—Client devices specifically adapted for the reception of or interaction with content, e.g. set-top-box [STB]; Operations thereof
- H04N21/41—Structure of client; Structure of client peripherals
- H04N21/426—Internal components of the client ; Characteristics thereof
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N5/00—Details of television systems
- H04N5/222—Studio circuitry; Studio devices; Studio equipment
- H04N5/262—Studio circuits, e.g. for mixing, switching-over, change of character of image, other special effects ; Cameras specially adapted for the electronic generation of special effects
- H04N5/268—Signal distribution or switching
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N9/00—Details of colour television systems
- H04N9/64—Circuits for processing colour signals
- H04N9/643—Hue control means, e.g. flesh tone control
Abstract
The invention discloses a format conversion circuit applied to a set top box, wherein the set top box is coupled to a display, and the format conversion circuit comprises an electro-optical conversion function circuit, a mapping circuit and an electro-optical conversion function circuit. The electro-optical conversion function circuit is used for converting an input image signal with a first format into a first optical signal; the mapping circuit is coupled to the electro-optic transfer function circuit and is used for converting the first optical signal into a second optical signal with a second format, wherein at least one of the first optical signal and the second optical signal is generated according to the maximum brightness of the display; and the photoelectric conversion function circuit is coupled to the mapping circuit and is used for converting the second optical signal into an output image signal.
Description
Technical Field
The present invention relates to a set top box, and more particularly, to a format conversion circuit applied to a set top box.
Background
In recent years, a part of image signals has adopted a High Dynamic Range (HDR) format. The high Dynamic Range (e.g., Range of about 0-10000 nits) may allow for higher contrast and sharper viewing of the displayed image than conventional Standard Dynamic Range (SDR) (e.g., Range of about 0-1000 nits). Because the current televisions do not all support the format with the high dynamic range, if the televisions are collocated with the set-top box, the set-top box converts the received image signal into the image signal with the format suitable for the television, that is, the set-top box can convert the image signal from the high dynamic range into the standard dynamic range and can also convert the image signal from the standard dynamic range into the high dynamic range. However, even if the set-top box can convert the image signal into a format suitable for television broadcasting, the maximum brightness output by the set-top box may still be different from the maximum brightness displayed by the display panel of the television, so that the image cannot be displayed well; in addition, even if the television has a function of re-adjusting the brightness, if the adjusting function is not complete, the display quality may be affected.
Disclosure of Invention
Therefore, one objective of the present invention is to provide a format conversion circuit applied in a set-top box, which can generate an output image signal according to the maximum brightness of a display, so that the maximum brightness of the output image signal is equal to the maximum brightness of the display. Therefore, the display at the back end can directly display the image data from the set-top box without adjusting the brightness, so as to solve the problems in the prior art.
In an embodiment of the present invention, a format conversion circuit applied to a set top box is disclosed, wherein the set top box is coupled to a display, and the format conversion circuit includes an electrical-to-optical conversion function circuit, a mapping circuit and an optical-to-electrical conversion function circuit. The electro-optical conversion function circuit is used for converting an input image signal with a first format into a first optical signal; the mapping circuit is coupled to the electro-optic transfer function circuit and is used for converting the first optical signal into a second optical signal with a second format, wherein at least one of the first optical signal and the second optical signal is generated according to the maximum brightness of the display; and the photoelectric conversion function circuit is coupled to the mapping circuit and is used for converting the second optical signal into an output image signal.
In another embodiment of the present invention, a format conversion circuit for a set-top box is disclosed, wherein the set-top box is coupled to a display, and the format conversion circuit comprises an electrical-to-optical conversion function circuit, a color space conversion circuit, an optical-to-electrical conversion function circuit, and a mapping circuit. The electro-optical conversion function circuit is used for converting an input image signal with a first format into an optical signal; the color space conversion circuit is used for performing color space conversion on the optical signal according to a target color space to generate a color-converted optical signal; the photoelectric conversion function circuit is coupled with the color space conversion circuit and is used for converting the color-converted optical signal into an electric signal; the mapping circuit is coupled to the photoelectric conversion function circuit and is used for converting the electric signal into an output image signal with a second format; wherein at least one of the light signal and the output image signal is generated in dependence on a maximum brightness of the display.
In another embodiment of the present invention, a format conversion method applied to a set-top box is disclosed, wherein the set-top box is coupled to a display, and the format conversion method comprises: converting an input image signal having a first format into a first optical signal; converting the first optical signal into a second optical signal having a second format, wherein at least one of the first optical signal and the second optical signal is generated according to the maximum brightness of the display; and converting the second optical signal into an output image signal.
In another embodiment of the present invention, a format conversion method applied to a set-top box is disclosed, wherein the set-top box is coupled to a display, and the format conversion method comprises: converting an input image signal having a first format into an optical signal; performing color space conversion on the optical signal according to a target color space to generate a color-converted optical signal; converting the color-converted optical signal into an electrical signal; and converting the electrical signal into an output image signal having a second format; wherein at least one of the light signal and the output image signal is generated in dependence on a maximum brightness of the display.
Drawings
Fig. 1 is a block diagram of a format conversion circuit according to an embodiment of the invention.
Fig. 2A is a diagram illustrating the conversion relationship between PQ codes and nits according to an embodiment of the present invention.
Fig. 2B is a diagram illustrating an operation of a mapping circuit according to an embodiment of the invention.
Fig. 3 is a block diagram of a format conversion circuit according to another embodiment of the invention.
Fig. 4 is a block diagram of a format conversion circuit according to another embodiment of the invention.
Fig. 5 is a diagram illustrating a conversion relationship between PQ codes and nits according to another embodiment of the present invention.
FIG. 6 is a diagram illustrating an operation of a mapping circuit according to another embodiment of the invention.
FIG. 7 is a block diagram of a format conversion circuit according to another embodiment of the invention.
FIG. 8 is a block diagram and an operational diagram of a format conversion circuit according to another embodiment of the invention.
FIG. 9 is a block diagram and an operational diagram of a format conversion circuit according to another embodiment of the invention.
FIG. 10 is a block diagram and an operational diagram of a format conversion circuit according to another embodiment of the invention.
FIG. 11 is a block diagram and an operational diagram of a format conversion circuit according to another embodiment of the invention.
Fig. 12 is a flowchart of a format conversion method according to an embodiment of the invention.
Fig. 13 is a flowchart of a format conversion method according to another embodiment of the present invention.
Description of the symbols
100. 300, 400, 700, 800, 900, 1000, 1100 format conversion circuit
102. 302, 402, 702, 802, 902, 1002, 1102 displays
110. 310, 410, 710, 810, 910, 1010, 1110 electro-optic transfer function circuit
120. 320, 420, 720, 820, 920, 1020, 1120 color space conversion circuit
130. 330, 430, 730, 830, 930, 1030, 1130 mapping circuit
140. 340, 440, 740, 840, 940, 1040, 1140 photoelectric conversion function circuit
1200 to 1208, 1300 to 1308
Detailed Description
Fig. 1 is a block diagram of a format conversion circuit 100 according to an embodiment of the invention. As shown in fig. 1, the format conversion circuit 100 includes an Electro-Optical Transfer Function (EOTF) circuit 110, a color-space conversion circuit 120, a mapping circuit 130, and an opto-electronic Transfer Function (OETF) circuit 140. In the embodiment, the format conversion circuit 100 is disposed in a set-top box, and is used for converting an input image signal having a High Dynamic Range (HDR) format into an output image signal having a Standard Dynamic Range (SDR), and transmitting the generated output image signal to the display 102 at the back end for displaying through the output circuit of the set-top box; in addition, in the present embodiment, the display 102 is a television. However, in other embodiments, the format conversion circuit 100 may be disposed in an image processing apparatus, and the display 102 may be a mobile device receiving the output signal of the image processing apparatus.
In the operation of the format conversion circuit 100, first, the electrical-to-optical conversion function circuit 110 converts the input image signal with high dynamic range into a first optical signal with high dynamic range. In detail, the input image signal is also referred to as PQ signal, and the pixel value of each pixel can be represented by a PQ code, and the electrical-to-optical conversion function circuit 110 can convert each PQ code in the input image signal into a corresponding nit value through the relationship between the PQ code and the nit value (nit) shown in fig. 2A, and the nit values are used as the first optical signal. In addition, the input image signal has a high dynamic range, so the range of the first optical signal is about 0 to 10000 nits.
The color space converting circuit 120 is configured to perform color space conversion on the first optical signal according to a color gamut (gamut) corresponding to a target color space to generate a color-converted first optical signal. In another embodiment, the color space conversion circuit 120 may be omitted if it is possible that none of the color gamuts corresponding to the color space of the received signal need to be converted.
The mapping circuit 130 converts the color-converted first optical signal into a second optical signal with a standard dynamic range according to the maximum brightness of the display 102, wherein the maximum brightness of the display 102 can be transmitted from the display 102 back to the format conversion circuit 100 through a connection line or input by a user. For example, the display 102 transmits Extended display capability identification data (EDID) to the conversion circuit 100 through the HDMI transmission line, wherein the EDID may include the maximum brightness of the display 102. Please note that the maximum brightness refers to the maximum brightness that can be displayed on the panel of the display 102, that is, when the brightness value that a pixel should display is greater than the maximum brightness, the pixel values of the pixel displayed on the display 102 are all the maximum brightness. Referring to fig. 2B, which is an operation diagram of the mapping circuit 130, the mapping circuit 130 may use a mapping function of an icon to convert the color-converted first optical signal (the maximum brightness value is about 10000 nits) into the second optical signal (the maximum brightness value is equal to/close to the maximum brightness of the display 102), as shown in fig. 2B, assuming that the maximum brightness of the display 102 is 1000 nits (corresponding to the mapping function a), the maximum brightness of the second optical signal is also equal to or very close to 1000 nits; similarly, assuming that the maximum brightness of the display 102 is 800 nits (corresponding to the mapping function b) or 400 nits (corresponding to the mapping function c), the maximum brightness of the second light signal is also equal to or very close to 800 nits or 400 nits, respectively. In addition, the transfer function has a linear region and a non-linear region, wherein the linear region has a smaller range when the maximum brightness of the display 102 is lower. For example, when the maximum brightness of the display 102 is 1000 nits, the linear region of the transfer function may range from 0 to 800 nits; similarly, when the maximum brightness of the display 102 is 800 nits or 400 nits, the linear region of the transfer function may be in the range of 0 to 600 nits or 0 to 200 nits.
The linear region determined by the maximum brightness of the display 102 can retain as much dark detail as possible without sacrificing brightness, and the less the maximum brightness of the display 102 is, the less the linear region is, the less the bright detail is compressed, thereby avoiding the loss of the bright detail.
In one embodiment, when the color-converted first light signal is within the linear region of the conversion function, the brightness value of the second light signal is the same as the brightness value of the color-converted first light signal.
Finally, the photoelectric conversion function circuit 140 converts the second optical signal into an output image signal and outputs the output image signal to the rear-end display 102. In detail, the photoelectric conversion function circuit 140 can convert each nit value of the second optical signal into a corresponding PQ code through the relationship between PQ codes and nit values (nit) shown in fig. 2A, and the PQ codes are used as the output video signal. In addition, the output image signal has a standard dynamic range format and the maximum luminance of the output image signal is not greater than the maximum luminance of the display 102.
As described above, since the maximum brightness of the output image signal generated by the format conversion circuit 100 is the maximum brightness of the display 102, the display 102 does not need to compress or extend the brightness of the image signal after receiving the image signal transmitted by the set-top box, thereby ensuring that the display quality is not reduced due to the brightness adjustment at the display end.
Fig. 3 is a block diagram of a format conversion circuit 300 according to another embodiment of the invention. The blocks of the format conversion circuit 300 are similar to those of the format conversion circuit 100, and therefore are not described in detail. However, the difference between the format conversion circuit 300 and the format conversion circuit 100 lies in the positions of the photoelectric conversion function circuit 340 and the mapping circuit 330, that is, in the format conversion circuit 300, the photoelectric conversion function circuit 340 converts a color-converted optical signal generated by the color space conversion circuit 320 into an electrical signal (PQ code), and then the mapping circuit 330 converts the electrical signal into an output image signal with a standard dynamic range. Since a person skilled in the art should understand the operation of the format conversion circuit 300 shown in fig. 3 after reading the above description of the embodiments of fig. 1, 2A and 2B, further description is omitted here for brevity.
Fig. 4 is a block diagram of a format conversion circuit 400 according to another embodiment of the invention. The structure of the format conversion circuit 400 is similar to that of the format conversion circuit 100, and therefore, the description thereof is omitted. In the operation of the format conversion circuit 400, the electro-optic conversion function circuit 410 further compresses the luminance of the input image signal according to the maximum luminance of the display 402 when converting the input image signal into a first optical signal, so that the maximum luminance of the first optical signal is between the maximum luminance of the high dynamic range specification (e.g., 10000 nits) and the maximum luminance of the display 402. In detail, referring to fig. 5, assuming that the maximum brightness of the display 402 is 1000 nits, the electro-optical conversion function circuit 410 converts each PQ code in the input image signal into a corresponding nit value through the relationship between PQ codes and nit (nit) shown in fig. 5, wherein the maximum brightness of the first optical signal is about 2000 nits.
Referring to fig. 6, an operation diagram of the mapping circuit 430 is shown. The difference from the mapping circuit 130 is that, since the brightness range of the first optical signal after color conversion in the format conversion circuit 400 is reduced to 0-2000 nits, the mapping circuit 430 can use the mapping function shown in fig. 6 to convert the first optical signal after color conversion into the second optical signal (the maximum brightness value is equal to/close to the maximum brightness (e.g., 1000 nits)) with less hardware cost, so that the embodiment can further reduce the cost and increase the processing efficiency compared to the embodiments shown in fig. 1 and 3.
Fig. 7 is a block diagram of a format conversion circuit 700 according to another embodiment of the invention. The blocks of the format conversion circuit 700 are similar to those of the format conversion circuit 400, and therefore are not described in detail. However, the difference between the format conversion circuit 700 and the format conversion circuit 400 is the positions of the photoelectric conversion function circuit 740 and the mapping circuit 730, that is, in the format conversion circuit 700, after the photoelectric conversion function circuit 740 converts a color-converted optical signal generated by the color space conversion circuit 720 into an electrical signal (PQ code), the mapping circuit 730 converts the electrical signal into an output image signal with a standard dynamic range. Since a person skilled in the art should understand the operation of the format conversion circuit 700 shown in fig. 7 after reading the contents of the embodiments of fig. 1 to 6, the details thereof are not repeated.
In the format conversion circuits 400 and 700, since the electro-optic transfer function circuit 410 or 710 performs luminance compression on the input image signal first, the data size of the first optical signal is greatly reduced, thereby reducing the hardware cost of the subsequent processing elements. For example, if the maximum brightness of the first optical signal is 10000 nits of the high dynamic range specification, 14 bits are required for each data of the first optical signal; if the maximum brightness of the first optical signal is compressed to 2000 nits in the above embodiment, only 11 bits are needed for each data of the first optical signal. In addition, the subsequent mapping circuit 130 or 430 has a higher precision from 0 to 2000 nit to 1000 nit than from 0 to 10000 nit to 1000 nit. In addition, in another embodiment, the electro-optic transfer function circuit 410 or 710 directly compresses the brightness of the input image signal to the maximum brightness of the display 402 or 702, then the mapping circuit 430 or 730 does not need to perform the conversion, or the mapping circuit 430 or 730 can be removed.
Fig. 8 is a block diagram and an operational diagram of a format conversion circuit 800 according to another embodiment of the invention. The blocks of the format conversion circuit 800 are similar to those of the format conversion circuit 100, and therefore are not described in detail. However, the format conversion circuit 800 is used to convert an input image signal having a Standard Dynamic Range (SDR) format into an output image signal having a High Dynamic Range (HDR), which is different from the format conversion circuit 100 in that the electrical-to-optical conversion function circuit 810 converts each PQ code in the input image signal into a corresponding nit value through a relationship diagram similar to the PQ code and nit (nit) shown in fig. 2A, and the nit values are used as the first optical signal, which has a range conforming to the High Dynamic Range (HDR), for example, the range of the first optical signal is about 0 to 10000 nit in this embodiment.
In addition, the operations of the color space converting circuit 820, the mapping circuit 830 and the photoelectric conversion function circuit 840 are similar to the color space converting circuit 120, the mapping circuit 130 and the photoelectric conversion function circuit 140 shown in fig. 1, and thus are not repeated.
Fig. 9 is a block diagram of a format conversion circuit 900 according to another embodiment of the invention. The blocks of the format conversion circuit 900 are similar to the format conversion circuit 800 shown in fig. 8, and therefore are not described again. The difference between the format conversion circuit 900 and the format conversion circuit 800 lies in the positions of the photoelectric conversion function circuit 940 and the mapping circuit 930, that is, in the format conversion circuit 900, the photoelectric conversion function circuit 940 converts a color-converted optical signal generated by the color space conversion circuit 920 into an electrical signal (PQ code), and then the mapping circuit 930 converts the electrical signal into an output image signal with a high dynamic range. Since a person skilled in the art can understand the operation of the format conversion circuit 900 shown in fig. 9 after reading the above description of the embodiment of fig. 8, the related details are not repeated.
Fig. 10 is a block diagram and an operational diagram of a format conversion circuit 1000 according to another embodiment of the invention. The blocks of the format conversion circuit 1000 are similar to those of the format conversion circuit 800, and therefore are not described in detail. However, in the operation of the format conversion circuit 1000, the electro-optical conversion function 1010 can convert the input image signal into a first optical signal, and adjust the brightness of the input image signal according to the maximum brightness of the display 1002, so that the maximum brightness of the first optical signal is equal to or very close to the maximum brightness of the display 1002.
In addition, since the maximum brightness of the color-converted first optical signal is equal to or very close to the maximum brightness of the display 1002, the mapping circuit 1030 can directly convert the color-converted first optical signal into a second optical signal at this time, and the brightness values of the color-converted first optical signal and the second optical signal are substantially the same. Alternatively, in the format conversion circuit 1000, the mapping circuit 1030 may be directly removed.
The operation of the color space converting circuit 1020 and the photoelectric conversion function circuit 1040 is similar to that of the color space converting circuit 820 and the photoelectric conversion function circuit 840, and thus is not described in detail. However, since finally, the second optical signal with the standard dynamic range format is converted into an output image signal to the back-end display 1002.
Fig. 11 is a block diagram of a format conversion circuit 1100 according to another embodiment of the invention. The blocks of the format conversion circuit 1100 are similar to those of the format conversion circuit 1000 shown in fig. 10, and thus are not described again. The difference between the format conversion circuit 1100 and the format conversion circuit 1000 is the positions of the photoelectric conversion function circuit 1140 and the mapping circuit 1130, that is, in the format conversion circuit 1100, after the photoelectric conversion function circuit 1140 converts a color-converted optical signal generated by the color space conversion circuit 1120 into an electrical signal (PQ code), the mapping circuit 1130 converts the electrical signal into an output image signal with high dynamic range. Since a person skilled in the art can understand the operation of the format conversion circuit 1100 shown in fig. 11 after reading the above description of the embodiment of fig. 10, the related details are not repeated.
In the above embodiments of fig. 8 and 9, the mapping circuit 830/930 converts the color-converted first light signal into a second light signal with high dynamic range according to the maximum brightness of the display 802/930; in the embodiment of fig. 10 and 11, the electro-optic transfer function 1010/1110 adjusts the brightness of the input image signal according to the maximum brightness of the display 1002/1102 so that the maximum brightness of the first light signal is generated to be equal to or very close to the maximum brightness of the display 1002/1102. In another embodiment of the present invention, the electro-optical conversion function circuit and the mapping circuit can adjust the brightness range of the output signal thereof with reference to the maximum brightness of the display (similar to the embodiments of fig. 4 and 7), and these design changes should fall into the scope of the present invention as long as the maximum brightness of the output image signal of the format conversion circuit is equal to the maximum brightness of the display.
Fig. 12 is a flowchart of a format conversion method according to an embodiment of the invention. With reference to the above embodiments for fig. 1, 4, 8, 10, the flow is as follows:
step 1200: the process begins.
Step 1202: an input image signal having a first format is converted into a first optical signal.
Step 1204: converting the first optical signal into a second optical signal having a second format, wherein at least one of the first optical signal and the second optical signal is generated according to the maximum brightness of the display.
Step 1206: the second optical signal is converted into an output image signal.
Step 1208: transmitting the output image signal to the display.
Fig. 13 is a flowchart of a format conversion method according to another embodiment of the present invention. With reference to the above embodiments for fig. 3, 7, 9, 11, the flow is as follows:
step 1300: the process begins.
Step 1302: an input image signal having a first format is converted into an optical signal.
Step 1304: the optical signal is color space converted according to a target color space to generate a color-converted optical signal.
Step 1306: and converting the color-converted optical signal into an electrical signal.
Step 1308: converting the electrical signal into an output image signal having a second format, wherein at least one of the optical signal and the output image signal is generated according to a maximum brightness of the display.
Step 1310: transmitting the output image signal to the display.
Briefly summarizing the present invention, in the format conversion circuit provided in the set-top box disclosed in the present invention, the maximum brightness of the output video signal is determined according to the maximum brightness of the rear-end display, and therefore, the rear-end display does not need to compress or extend the brightness of the video signal after receiving the video signal transmitted from the set-top box, and thus, the good display quality can be maintained.
The above-mentioned embodiments are merely preferred embodiments of the present invention, and all equivalent changes and modifications made by the claims of the present invention should be covered by the scope of the present invention.
Claims (14)
1. A format conversion circuit applied to a set-top box, wherein the set-top box is coupled to a display, and the format conversion circuit comprises:
an electro-optical transfer function circuit for converting an input image signal having a first format into a first optical signal, the electro-optical transfer function circuit further compressing the luminance of the input image signal according to the maximum luminance of the display such that the maximum luminance of the first optical signal is lower than the maximum luminance of the high dynamic range specification but the maximum luminance of the first optical signal is higher than the maximum luminance of the display;
a mapping circuit, coupled to the electrical-to-optical conversion function circuit, for converting the first optical signal into a second optical signal having a second format, wherein the second optical signal is generated according to a maximum brightness of the display; and
and a photoelectric conversion function circuit coupled to the mapping circuit for converting the second optical signal into an output image signal.
2. The format conversion circuit of claim 1, wherein a maximum brightness of the second optical signal is equal to the maximum brightness of the display.
3. The format conversion circuit of claim 1, wherein the first format is high dynamic range and the second format is standard dynamic range.
4. The format conversion circuit of claim 3, wherein the mapping circuit uses a mapping function to convert the first light signal into the second light signal having the second format, the mapping function includes a linear region and a non-linear region, and the linear region is smaller when the maximum brightness of the display is lower.
5. The format conversion circuit of claim 4, wherein the brightness value of the second optical signal is the same as the brightness value of the first optical signal when the first optical signal is within the linear region.
6. The format conversion circuit of claim 1, wherein the mapping circuit converts the first optical signal into the second optical signal having the second format according to the maximum brightness of the display, such that the maximum brightness of the second optical signal is equal to the maximum brightness of the display.
7. A format conversion circuit applied to a set-top box, wherein the set-top box is coupled to a display, and the format conversion circuit comprises:
an electro-optical transfer function circuit for converting an input image signal having a first format into an optical signal, the electro-optical transfer function circuit further compressing the luminance of the input image signal according to the maximum luminance of the display such that the maximum luminance of the generated optical signal is lower than the maximum luminance of the high dynamic range specification but higher than the maximum luminance of the display;
a color space conversion circuit for performing color space conversion on the optical signal according to a target color space to generate a color-converted optical signal;
a photoelectric conversion function OETF circuit coupled to the color space conversion circuit for converting the color-converted optical signal into an electrical signal; and
a mapping circuit, coupled to the photoelectric conversion function circuit, for converting the electrical signal into an output image signal having a second format;
wherein the output image signal is generated according to a maximum brightness of the display.
8. The format conversion circuit of claim 7, wherein a maximum brightness of the output image signal is equal to the maximum brightness of the display.
9. The format conversion circuit of claim 7, wherein the first format is high dynamic range and the second format is standard dynamic range.
10. The format conversion circuit of claim 9, wherein the mapping circuit uses a mapping function to convert the electrical signal into the output image signal having the second format, the mapping function includes a linear region and a non-linear region, and the linear region is smaller as the maximum brightness of the display is lower.
11. The format conversion circuit of claim 10, wherein when the electrical signal is within the linear region, the output image signal represents a luminance value identical to a luminance value represented by the electrical signal.
12. The format conversion circuit of claim 7, wherein the mapping circuit converts the electrical signal into the output image signal having the second format according to a maximum brightness of the display such that the maximum brightness of the output image signal is equal to the maximum brightness of the display.
13. A format conversion method applied to a set top box, wherein the set top box is coupled to a display, and the format conversion method comprises the following steps:
converting an input image signal having a first format into a first optical signal, wherein the brightness of the input image signal is compressed according to the maximum brightness of the display, so that the maximum brightness of the first optical signal is lower than that of the high dynamic range specification, but the maximum brightness of the first optical signal is higher than that of the display;
converting the first optical signal into a second optical signal having a second format, wherein the second optical signal is generated according to the maximum brightness of the display; and
the second optical signal is converted into an output image signal.
14. A format conversion method applied to a set top box, wherein the set top box is coupled to a display, and the format conversion method comprises the following steps:
converting an input image signal having a first format into an optical signal, wherein the brightness of the input image signal is compressed according to the maximum brightness of the display, so that the maximum brightness of the generated optical signal is lower than the maximum brightness of the high dynamic range specification, but the maximum brightness of the optical signal is higher than the maximum brightness of the display;
performing color space conversion on the optical signal according to a target color space to generate a color-converted optical signal;
converting the color-converted optical signal into an electrical signal; and
converting the electrical signal into an output image signal having a second format;
wherein the output image signal is generated according to a maximum brightness of the display.
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Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106134172A (en) * | 2014-06-10 | 2016-11-16 | 松下知识产权经营株式会社 | Display system, display packing and display device |
| CN106791865A (en) * | 2017-01-20 | 2017-05-31 | 杭州当虹科技有限公司 | The method of the self adaptation form conversion based on high dynamic range video |
| CN107211079A (en) * | 2015-12-17 | 2017-09-26 | 皇家飞利浦有限公司 | Dynamic range for image and video is encoded |
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| CN106233741B (en) * | 2014-06-30 | 2020-02-14 | 松下知识产权经营株式会社 | Data reproducing method and reproducing apparatus |
| JP6619813B2 (en) * | 2014-12-11 | 2019-12-11 | コーニンクレッカ フィリップス エヌ ヴェＫｏｎｉｎｋｌｉｊｋｅ Ｐｈｉｌｉｐｓ Ｎ．Ｖ． | Optimizing high dynamic range images for specific displays |
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Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106134172A (en) * | 2014-06-10 | 2016-11-16 | 松下知识产权经营株式会社 | Display system, display packing and display device |
| CN107211079A (en) * | 2015-12-17 | 2017-09-26 | 皇家飞利浦有限公司 | Dynamic range for image and video is encoded |
| CN106791865A (en) * | 2017-01-20 | 2017-05-31 | 杭州当虹科技有限公司 | The method of the self adaptation form conversion based on high dynamic range video |
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