WO2016033791A1 - Generating method and apparatus for palette, and image processing device - Google Patents

Abstract

Provided are a generating method and apparatus for a palette, and an image processing device. The generating method comprises: determining an initial palette according to the occurrence frequency of pixel values of a plurality of pixels, adopting palette modes in an image region to be coded, in the image region to be coded; determining index copy information of the image region to be coded based on the initial palette; and according to the occurrence frequency of pixel indexes corresponding to the pixel values in the index copy information, updating the initial palette to determine the updated palette. The palette can be further optimized, and the bit cost for coding is better reduced.

Description

Palette generation method, device and image processing device Technical field

The present invention relates to the field of graphic image technology, and in particular, to a method and device for generating a color palette and an image processing device.

Background technique

Palette-based coding is widely used in graphic image technology (especially video coding technology). In the encoding process, for the image area to be encoded, for example, a coding unit (CU), including a plurality of pixels having color values (for example, RGB mode, having 24 bits of true color); in order to reduce the storage bits The storage capacity of the image image, which can usually point the pixel to the data index of the palette. During the decoding process, the color value of each output pixel can be determined by looking up a palette with a corresponding data index.

The palette is a set of pixel values. For pixels whose pixel values are in the palette, only the pixel index corresponding to the pixel value in the palette is used. Thereby, only the palette and the index corresponding to the pixels in the coding unit can be bit-stream encoded, and the bit cost of the coding can be reduced.

In order to further reduce the bit cost, index run information can be used when performing bit stream encoding. For example, if the pixel value of a pixel in the CU is the same as the pixel value of the left pixel, the index copy information may be generated in a copy left mode; if the pixel value of a pixel in the CU and the pixel value of the upper pixel Similarly, the index copy information can be generated in a copy above mode.

The following is a list of documents useful for understanding the present invention and conventional techniques, which are incorporated herein by reference as if fully set forth herein.

[Non-Patent Document 1]: JCTVC-O0182.Xun Guo, etc, Microsoft, Major-color-based screen content coding.

[Non-Patent Document 2]: JCTVC-N0249. Liwei Guo, etc, Qualcomm, Modified Palette Mode for Screen Content Coding.

[Non-Patent Document 3]: JCTVC-Q0094.Wei Pu,etc.,Suggested Software for Palette Coding based on RExt6.0.

It should be noted that the above description of the technical background is only for the purpose of facilitating a clear and complete description of the technical solutions of the present invention, and is convenient for understanding by those skilled in the art. The above technical solutions are not considered to be well known to those skilled in the art simply because these aspects are set forth in the background section of the present invention.

Summary of the invention

Currently, the palette can be determined based on the number of times the pixel value appears in the image region to be encoded (eg, CU), and the pixel index of the palette is represented by a variable-length code. For example, the pixel value with the most occurrence corresponds to the smallest pixel index (for example, index is 0, denoted by 0), and the pixel number of the second most frequent occurrence corresponds to the second small pixel index (for example, index is 1, indicated by 10), ....

However, the inventor found that the current scheme does not take into account the use of index copy information. In the case of using index copy information, more bits are still needed, and the palette cannot be further optimized, and the encoded bits cannot be better reduced. cost.

Embodiments of the present invention provide a method, an apparatus, and an image processing apparatus for generating a color palette. Further optimize the palette to better reduce the bit cost of the encoding.

According to a first aspect of the embodiments of the present invention, a method for generating a color palette is provided, including:

Determining, by the plurality of pixels adopting the palette mode in the image region to be encoded, an initial palette according to the number of times the pixel value of the pixel appears in the image region to be encoded;

Determining index copy information of the image area to be encoded based on the initial palette;

And updating the initial palette to determine the updated palette according to the number of occurrences of the pixel index corresponding to the pixel value in the index copy information.

According to a second aspect of the embodiments of the present invention, a device for generating a color palette is provided, including:

The initial palette determining unit determines, for a plurality of pixels adopting the palette mode in the image region to be encoded, an initial palette according to the number of times the pixel value of the pixel appears in the image region to be encoded;

a copy information determining unit that determines index copy information of the image area to be encoded based on the initial palette;

The palette updating unit updates the initial palette to determine the updated palette according to the number of occurrences of the pixel index corresponding to the pixel value in the index copy information.

According to a third aspect of the embodiments of the present invention, there is provided an image processing apparatus comprising the apparatus for generating a palette as described above.

According to still another aspect of an embodiment of the present invention, a computer readable program is provided, wherein when the program is executed in an image processing apparatus, the program causes a computer to perform color grading as described above in the image processing apparatus The method of generating the board.

According to still another aspect of an embodiment of the present invention, a storage medium storing a computer readable program, wherein the computer readable program causes a computer to execute a method of generating a color palette as described above in an image processing apparatus.

An advantageous effect of the embodiment of the present invention is that the initial palette is updated to determine the updated palette according to the number of occurrences of the pixel index corresponding to the pixel value in the index copy information. The palette can be further optimized to better reduce the bit cost of the encoding.

Specific embodiments of the present invention are disclosed in detail with reference to the following description and the drawings, in which <RTIgt; It should be understood that the embodiments of the invention are not limited in scope. The embodiments of the present invention include many variations, modifications, and equivalents within the scope of the appended claims.

Features described and/or illustrated with respect to one embodiment may be used in one or more other embodiments in the same or similar manner, in combination with, or in place of, features in other embodiments. .

It should be emphasized that the term "comprising" or "comprises" or "comprising" or "comprising" or "comprising" or "comprising" or "comprises"

DRAWINGS

Many aspects of the invention can be better understood with reference to the following drawings. The components in the figures are not drawn to scale, but only to illustrate the principles of the invention. In order to facilitate the illustration and description of some parts of the invention, the corresponding parts in the figures may be enlarged or reduced.

Elements and features described in one of the figures or one embodiment of the invention may be combined with elements and features illustrated in one or more other figures or embodiments. In the accompanying drawings, like reference numerals refer to the

1 is a schematic diagram of an example of a coding unit according to an embodiment of the present invention;

2 is a schematic diagram of a method for generating a color palette according to an embodiment of the present invention;

3 is a schematic diagram of an image encoding method according to an embodiment of the present invention;

4 is a schematic diagram of a device for generating a color palette according to an embodiment of the present invention;

FIG. 5 is a schematic diagram of an image encoding apparatus according to an embodiment of the present invention; FIG.

Fig. 6 is a block diagram showing the configuration of an image processing apparatus according to an embodiment of the present invention.

detailed description

The foregoing and other features of the present invention will be apparent from the The specific embodiments of the present invention are disclosed in the specification and the drawings, which are illustrated in the embodiment of the invention The invention includes all modifications, variations and equivalents falling within the scope of the appended claims.

1 is a schematic diagram showing an example of a coding unit according to an embodiment of the present invention, showing a case of a coding unit (CU). As shown in FIG. 1, the coding unit has 8 x 8 pixels; wherein the 8 x 8 pixels have different 7 pixel values (representing different colors). For the sake of simplicity, pixels having the same pixel value in FIG. 1 use the same symbol to represent pixel values, for example, C0, C1, ..., C6 are used to represent different pixel values.

Wherein, the initial palette may be determined according to the number of times the pixel value appears in the image area to be encoded. Table 1 shows the palette determined by the CU shown in Fig. 1 or 2. As shown in Table 1, C0 appears 43 times in the CU, C1 appears 8 times in the CU, C2 appears 6 times in the CU, C3 appears 4 times in the CU, and C4, C5 C6 appears in the CU one time. Therefore, the pixel index corresponding to C0 is determined to be 0, the pixel index corresponding to C1 is 1, the pixel index corresponding to C2 is 2, the pixel index corresponding to C3 is 3, the pixel index corresponding to C4 is 4, and the pixel index corresponding to C5 is 5. The pixel index corresponding to C6 is 6; the palette thus determined is as shown in the first two rows of Table 1.

Table 1

Pixel index	0	1	2	3	4	5	6
								Pixel values	C0	C1	C2	C3	C4	C5	C6
The number of times a pixel value appears in the CU	43	8	6	4	1	1	1
								The number of times the index appears in the index run	1	3	3	1	1	1	1

However, when the index copy information is employed, the index copy information generated based on the palette may be as shown in Table 2 below. Table 2 shows the index run information of the CU shown in Fig. 1 which is formed based on the palette of Table 1.

Table 2

Left(0,31)
	Left(2,0)
Above(3)
	Left(3,0)
Left(1,0)
	Left(2,0)
Left(1,0)
	Left(4,0)
Above(6)
	Left(5,0)
Left(6,0)
	Above(5)
Left(1,0)
	Left(2,0)
Above(4)

As shown in FIG. 1, there are pixels in the CU having 32 consecutive pixel values of C0 (the corresponding pixel index in the palette is 0), thus forming the index copy information Left(0, 31) in Table 2; There is one pixel in the CU having a pixel value of C2 (the corresponding pixel index in the palette is 2), thus forming the index copy information Left(2, 0) in Table 2; then having and above in the CU a row of corresponding pixels with the same pixel value of 4 pixels (pixel values are C0, C0, C0, C0), thus forming the index copy information in Table 2 Above (3);

Then there is one pixel in the CU having a pixel value of C3 (the corresponding pixel index in the palette is 3), thus forming index copy information Left(3, 0) in Table 2; having 1 in the CU A pixel having a pixel value of C1 (the corresponding pixel index in the palette is 1), thus forming index copy information Left(1, 0) in Table 2; having 1 pixel value in the CU is C2 (palette) The corresponding pixel index is 2) pixels, thus forming the index copy information Left(2,0) in Table 2; there is 1 pixel value C1 in the CU (the corresponding pixel index in the palette is 1) Pixels, thus forming the index copy information Left(1,0) in Table 2; having 1 pixel value in the CU with a pixel value of C4 (the corresponding pixel index in the palette is 4), thus forming Table 2 Index copy information Left(4,0);

Then, in the CU, there are 7 pixels having the same pixel value as the corresponding pixel of the previous row (the pixel values are C0, C0, C0, C3, C1, C2, C1, respectively), thus forming the index copy information in Table 2 (6); having one pixel in the CU having a pixel value of C5 (the corresponding pixel index in the palette is 5), thus forming the index copy information Left(5, 0) in Table 2; in the CU a pixel having a pixel value of C6 (the corresponding pixel index in the palette is 6), thus forming the index copy information Left(6, 0) in Table 2;

Then, in the CU, there are 6 pixels having the same pixel value as the corresponding pixel of the previous row (the pixel values are C0, C0, C3, C1, C2, C1, respectively), thus forming the index copy information in Table 2 (5) a pixel having 1 pixel value C1 (the corresponding pixel index in the palette is 1) in the CU, thus forming index copy information Left(1, 0) in Table 2; having 1 in the CU The pixel value is C2 (the corresponding pixel index in the palette is 2), thus forming the index copy information Left(2, 0) in Table 2; finally, the pixel having the corresponding pixel in the CU in the CU The five pixels having the same value (the pixel values are C0, C0, C3, C1, C2, respectively), thus forming the index copy information Above (4) in Table 2.

After the above-described index copy information is generated, when bit stream encoding is performed, it is necessary to encode, for example, 0 and 31 in Left (0, 31). However, based on the index copy information formed by the above palette, when the variable length code is used to represent the pixel index, as shown in the last row of Table 1, the pixel indexes "1" and "2" appear three times, respectively, and therefore need to be more More bits can be encoded. The embodiments of the present invention are described in detail below, and the palette is further optimized to reduce the bit cost of encoding.

Example 1

The embodiment of the present invention provides a method for generating a color palette, and FIG. 2 is a schematic diagram of a method for generating a color palette according to an embodiment of the present invention. As shown in FIG. 2, the generating method includes:

Step 201: Determine, for a plurality of pixels adopting the palette mode in the image region to be encoded, an initial palette according to the number of times the pixel value of the pixel appears in the image region to be encoded;

Step 202: Determine index copy information of an image region to be encoded based on an initial palette; and

Step 203: Update the initial palette to determine the updated palette according to the number of occurrences of the pixel index corresponding to the pixel value in the index copy information.

In this embodiment, the image area to be encoded may be a coding unit CU or a maximum coding unit LCU (Largest Coding Unit); the following uses CU as an example for description. Embodiments of the present invention are applicable to the case of adopting a palette mode, and in the case of mixing a palette mode and a non-palette mode (for example, an escape mode), Embodiments of the invention are equally applicable.

In this embodiment, in step 201, the number of times the pixel value appears in the image area to be encoded may be arranged in descending order, and the pixel index corresponding to the pixel value in the initial palette is determined according to the sorting result. As described earlier, the initial palette can be determined based on the number of times the pixel value appears in the image region to be encoded.

And, in step 202, index copy information of the image region to be encoded may be determined based on the initial palette. The index copy information can be generated by pressing the Copy Left mode and/or the Copy Above mode. However, the present invention is not limited thereto. For example, index copy information may be generated in other manners. The following uses CopyLeft and CopyAbove as an example for description. For example, index copy information as shown in Table 2 can be obtained.

After that, the index copy information may be counted to obtain the number of occurrences of the pixel index in the index copy information. For example, as shown in the last row of Table 1, when the CU of FIG. 1 adopts the palette as shown in Table 1, the pixel indexes 0 to 6 corresponding to the pixel values C0 to C6 appear in the index as shown in Table 2. The number of times in the copy information is 1, 3, 3, 1, 1, 1, and 1, respectively.

In this embodiment, step 203 may update the initial palette to determine the updated palette based on the number of occurrences of the pixel index in the index copy information. Specifically, the number of occurrences of the pixel index corresponding to the pixel value in the index copy information may be arranged in descending order, and the pixel index corresponding to the pixel value in the updated palette may be determined according to the sorting result.

For example, 1, 3, 3, 1, 1, 1, 1 can be arranged in descending order to 3, 3, 1, 1, 1, 1, 1, and the corresponding pixel index is changed correspondingly according to the arrangement result. For example, the pixel index corresponding to the pixel value C1 that appears three times is changed from 1 to 0, and the pixel index corresponding to the pixel value C2 that appears three times is changed from 2 to 1, and the pixel value C0 that will appear once corresponds to The pixel index is changed from 0 to 2, thus forming Table 3 below:

table 3

Pixel index	0	1	2	3	4	5	6
								Pixel values	C1	C2	C0	C3	C4	C5	C6
The number of times a pixel value appears in the CU	8	6	43	4	1	1	1
								The number of times the index appears in the index run	3	3	1	1	1	1	1

Thus, the resulting updated palette is as shown in the first two rows of Table 3.

In this embodiment, after forming the updated palette, it is also possible to re-based the updated palette. Determining index copy information of the image area to be encoded; and performing bit stream encoding on the plurality of pixels in the palette mode based on the re-determined index copy information.

3 is a schematic diagram of an image encoding method according to an embodiment of the present invention, which uses bit index copy information formed based on an updated palette to perform bit stream encoding. As shown in FIG. 3, the image encoding method includes:

Step 301: Determine, for a plurality of pixels adopting the palette mode in the image region to be encoded, an initial palette according to the number of times the pixel value of the pixel appears in the image region to be encoded;

Step 302: Determine index copy information of an image region to be encoded based on an initial palette;

Step 303: Update the initial palette to determine the updated palette according to the number of occurrences of the pixel index corresponding to the pixel value in the index copy information.

Step 304, re-determining index copy information of the image area to be encoded based on the updated palette;

Step 305: Perform bitstream encoding on a plurality of pixels adopting the palette mode based on the re-determined index copy information.

Steps 301 to 303 may be as described in the previous steps 201 to 203.

In step 304, the index copy information of the image region to be encoded may be re-determined based on the updated palette. For example, for the CU shown in FIG. 1 and the updated palette shown in Table 3, the updated index copy information shown in Table 4 below can be determined.

Table 4

Left(2,31)
	Left(1,0)
Above(3)
	Left(3,0)
Left(0,0)
	Left(1,0)
Left(0,0)
	Left(4,0)
Above(6)
	Left(5,0)
Left(6,0)
	Above(5)

Left(0,0)
	Left(1,0)
Above(4)

In step 305, bitstream encoding of a plurality of pixels in a palette mode may be performed based on the re-determined index copy information.

In this embodiment, regarding the specific how to perform bit stream coding, reference may be made to related art. The following uses only the updated palette of the embodiment of the present invention to illustrate how to further reduce the bit cost of the encoding.

In the present embodiment, the pixel index in the updated palette is represented by a variable length code. For example, as shown in Table 5, the pixel index 0 is represented by "0" (1 bit), and the pixel index 1 is represented by "10" (two bits), ....

table 5

Pixel index	Variable length code
		0	0
1	10
		2	110
3	1110
		4	11110
5	111110
		6	1111110

It should be noted that Table 5 only schematically shows the variable length code of the embodiment of the present invention, but the present invention is not limited thereto. For example, other variable length codes may be determined according to actual conditions.

Thus, when the initial palette shown in Table 1 is employed, since the pixel index 0 (corresponding pixel value C0) appears once in the index copy information, the pixel index 1 (corresponding pixel value C1) is in the index copy information. Appeared 3 times, the pixel index 2 (corresponding to the pixel value C2) appears 3 times in the index copy information. For the index copy information as shown in Table 2, the corresponding bits of the pixel values C0, C1, C2 are required. 1*1+2*3+3*3=16 bits.

When the updated palette shown in Table 3 is used, since the pixel index 0 (corresponding to the pixel value C1) appears three times in the index copy information, the pixel index 1 (corresponding to the pixel value C2) is in the index copy information. Appeared 3 times, the pixel index 2 (corresponding to the pixel value C0) appears once in the index copy information. For the index copy information as shown in Table 4, the corresponding bits of the pixel values C0, C1, C2 are required. 1*3+2*3+3*1=12 bits. This reduces 16-12 = 4 bits.

It can be seen from the above embodiment that the initial palette is updated to determine the updated palette according to the number of occurrences of the pixel index corresponding to the pixel value in the index copy information. The palette can be further optimized to better reduce the bit cost of the encoding.

Example 2

The embodiment of the present invention provides a device for generating a color palette, which corresponds to the method for generating a color palette in the first embodiment, and the same content is not described herein.

4 is a schematic diagram of a color palette generating apparatus according to an embodiment of the present invention. As shown in FIG. 4, the palette generating apparatus 400 includes an initial palette determining unit 401, a copy information determining unit 402, and a color palette. Board update unit 403;

Wherein, the initial palette determining unit 401 determines, for a plurality of pixels adopting the palette mode in the image region to be encoded, an initial palette according to the number of times the pixel value of the pixel appears in the image region to be encoded; The information determining unit 402 determines the index copy information of the image region to be encoded based on the initial palette; and the number of times the palette updating unit 403 appears in the index copy information according to the pixel index corresponding to the pixel value, The initial palette is updated to determine the updated palette.

In the present embodiment, the pixel index in the updated palette is represented by a variable length code. The index copy information may include information generated by a copy left (Copy Left) mode and/or a copy above (Copy Above) mode. However, the present invention is not limited thereto, and for example, other methods may be used to generate index copy information.

In this embodiment, the initial palette determining unit 401 is specifically configured to: arrange the number of times the pixel value appears in the image to be encoded region in descending order, and determine the pixel value according to the sorting result. The pixel index corresponding to the initial palette.

In this embodiment, the palette updating unit 403 may be specifically configured to: arrange the number of occurrences of the pixel index corresponding to the pixel value in the index copy information in descending order, and determine the pixel according to the sorting result. The value is the pixel index corresponding to the updated palette.

In this embodiment, the palette generating apparatus 400 may further include: a copy information updating unit and a bit stream encoding unit (not shown in FIG. 4); wherein the copy information updating unit re-determines based on the updated palette Index copy information of the image area to be encoded; and the bit stream encoding unit performs bit stream encoding on the plurality of pixels in the palette mode based on the re-determined index copy information.

FIG. 5 is a schematic diagram of an image encoding apparatus according to an embodiment of the present invention, including a palette generating apparatus 400 as shown in FIG. As shown in FIG. 5, the palette generating apparatus 400 includes an initial palette determining unit 401, a copy information determining unit 402, and a palette updating unit 403.

As shown in FIG. 5, the image encoding apparatus 500 may further include: a copy information updating unit 404 and a bit stream encoding unit 405; wherein the copy information updating unit 404 re-determines the index copy information of the image area to be encoded based on the updated palette And the bitstream encoding unit 405 performs bitstream encoding on a plurality of pixels adopting the palette mode based on the re-determined index copy information.

It can be seen from the above embodiment that the initial palette is updated to determine the updated palette according to the number of occurrences of the pixel index corresponding to the pixel value in the index copy information. The palette can be further optimized to better reduce the bit cost of the encoding.

Example 3

An embodiment of the present invention provides an image processing apparatus including: a palette generating apparatus 400 as described in Embodiment 2, or an image encoding apparatus 500.

Fig. 6 is a block diagram showing the configuration of an image processing apparatus according to an embodiment of the present invention. As shown in FIG. 6, the image processing apparatus 600 may include a central processing unit (CPU) 100 and a memory 110; the memory 110 is coupled to the central processing unit 100. The memory 110 can store various data; in addition, a program for information processing is stored, and the program is executed under the control of the central processing unit 100.

In one embodiment, the functions of the palette generating device 400 or the image encoding device 500 may be integrated into the central processing unit 100. The central processing unit 100 may be configured to implement the method for generating a color palette or the image encoding method as described in Embodiment 1.

In another embodiment, the palette generating device 400 or the image encoding device 500 may be configured separately from the central processing unit. For example, the palette generating device 400 or the image encoding device 500 may be configured to be connected to the central processing unit 100. The chip implements the functions of the palette generating device 400 or the image encoding device 500 by the control of the central processing unit.

In addition, as shown in FIG. 6, the image processing apparatus 600 may further include: an input and output unit 120, a display unit 130, and the like; wherein the functions of the above components are similar to those of the prior art, and are not described herein again. It is to be noted that the image processing apparatus 600 does not necessarily have to include all of the components shown in FIG. 6; in addition, the image processing apparatus 600 may further include components not shown in FIG. 6, and reference may be made to the related art.

In the present embodiment, the image processing apparatus 600 may further include: an image decoding device that can perform decoding correspondingly. The image processing apparatus 600 can implement the functions of the image decoding apparatus by the control of the central processing unit 100 as described above.

The embodiment of the present invention further provides a computer readable program, wherein when the program is executed in an image processing device, the program causes a computer to execute the generation of the color palette described in Embodiment 1 in the image processing device Method or image coding method.

The embodiment of the present invention further provides a storage medium storing a computer readable program, wherein the computer readable program causes a computer to execute the method for generating a palette or the image encoding method described in Embodiment 1 in an image processing device.

The above apparatus and method of the present invention may be implemented by hardware or by hardware in combination with software. The present invention relates to a computer readable program that, when executed by a logic component, enables the logic component to implement the apparatus or components described above, or to cause the logic component to implement the various methods described above Or steps. The present invention also relates to a storage medium for storing the above program, such as a hard disk, a magnetic disk, an optical disk, a DVD, a flash memory, or the like.

One or more of the functional blocks described in the figures and/or one or more combinations of functional blocks may be implemented as a general purpose processor, digital signal processor (DSP) for performing the functions described herein. An application specific integrated circuit (ASIC), field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic device, discrete hardware component, or any suitable combination thereof. One or more of the functional blocks described with respect to the figures and/or one or more combinations of functional blocks may also be implemented as a combination of computing devices, eg, a combination of a DSP and a microprocessor, multiple microprocessors One or more microprocessors in conjunction with DSP communication or any other such configuration.

The present invention has been described in connection with the specific embodiments thereof, and it should be understood by those skilled in the art that A person skilled in the art can make various modifications and changes to the present invention within the scope of the present invention.

Claims (14)

1. A method for generating a color palette, wherein the generating method comprises:

   Determining, by the plurality of pixels adopting the palette mode in the image region to be encoded, an initial palette according to the number of times the pixel value of the pixel appears in the image region to be encoded;

   Determining index copy information of the image area to be encoded based on the initial palette;

   And updating the initial palette to determine the updated palette according to the number of occurrences of the pixel index corresponding to the pixel value in the index copy information.
2. The generating method according to claim 1, wherein the pixel index in the updated palette is represented by a variable length code.
3. The generating method according to claim 1, wherein the method further comprises:

   Re-determining index copy information of the image area to be encoded based on the updated palette;

   The bit stream encoding is performed on the plurality of pixels in the palette mode based on the re-determined index copy information.
4. The generating method according to claim 1, wherein determining an initial palette according to a number of occurrences of pixel values of the pixel in the image region to be encoded comprises:

   Arranging the number of times the pixel value appears in the image area to be encoded in descending order, and

   A pixel index corresponding to the pixel value in the initial palette is determined according to the sorting result.
5. The generating method according to claim 1, wherein the initial palette is updated to determine an updated palette according to a number of occurrences of the pixel index corresponding to the pixel value in the index copy information. include:

   Arranging the number of occurrences of the pixel index in the index copy information in descending order, and

   Determining, according to the sorting result, a pixel index corresponding to the pixel value in the updated palette.
6. The generating method according to claim 1, wherein the index copy information comprises information generated by pressing the left copy mode and/or pressing the copy mode.
7. A palette generating device, wherein the generating device comprises:

   The initial palette determining unit determines, for a plurality of pixels adopting the palette mode in the image region to be encoded, an initial palette according to the number of times the pixel value of the pixel appears in the image region to be encoded;

   a copy information determining unit that determines an index copy letter of the image area to be encoded based on the initial palette Interest;

   The palette updating unit updates the initial palette to determine the updated palette according to the number of occurrences of the pixel index corresponding to the pixel value in the index copy information.
8. The generating apparatus according to claim 7, wherein the pixel index in the updated palette is represented by a variable length code.
9. The generating device of claim 7, wherein the device further comprises:

   a copy information update unit that re-determines index copy information of the image area to be encoded based on the updated palette;

   The bitstream encoding unit performs bitstream encoding on the plurality of pixels in the palette mode based on the re-determined index copy information.
10. The generating apparatus according to claim 7, wherein the initial palette determining unit is configured to: arrange the number of occurrences of the pixel value in the image area to be encoded in descending order, and determine the result according to the sorting result The pixel index corresponding to the pixel value in the initial palette.
11. The generating device according to claim 7, wherein the palette updating unit is configured to: arrange the number of occurrences of the pixel index corresponding to the pixel value in the index copy information in descending order, and sort by The result determines a pixel index corresponding to the pixel value in the updated palette.
12. The generating apparatus according to claim 7, wherein said index copy information comprises information generated by pressing left copy mode and/or pressing copy mode.
13. An image processing apparatus comprising: a palette generating device according to any one of claims 7 to 12.
14. The image processing device according to claim 13, wherein the image processing device further comprises:

    A decoding device that decodes the bitstream to obtain an image.

Images