TWI581617B - Method and system for encoding and decoding, encoder and decoder - Google Patents

Description

Encoding method and decoding method, codec system, encoder and decoder

The present disclosure relates to an encoding method and a decoding method for encoding and decoding a coding unit, and a codec system, an encoder and a decoder using the same.

With the evolution of technology, the resolution, specifications and size of video displays are getting higher and higher, and people's requirements for video picture quality and size are also rising. In order to meet this demand, the Video Coding Experts Group under the International Telecommunication Union (ITU-T) and the MPEG (Moving Picture Experts Group) under the International Organization for Standardization ISO/IEC have established video coding. Joint Working Group JCT-VC (Joint Collaborative Team on Video Coding) and started the H.265/HEVC (High Efficiency Video Coding) project with the goal of providing higher video compression standards than H.264/AVC (Advanced Video Coding). Coding efficiency (about 50% bit rate under the same subjective quality), especially high definition (HD), ultra high resolution (Ultra High) Definition, Ultra HD) and other high resolution video is heavy.

This large-size and high-resolution video application environment is dominated by natural video images and was developed in 2013. Currently, H.265/HEVC Range Extensions are being developed, including The Screen Content Coding (SCC) standard required for the screen sharing application service. The video content shared by the screen usually has mixed video content material. For example, the screen may contain natural images, a large number of text images, mouse pointers and various lines, etc., because the screen application environment has not been designed by H.265/HEVC. The goal, so JCT-VC has recently shifted its focus to the development of new high-performance screen coding standard technology. The SCC standard is developed based on the existing tools of H.265/HEVC, for example, single color mode and palette mode, etc., which is an encoding technology belonging to the SCC standard.

The single color mode is to search for all the pixels in the coding unit block by searching for neighboring pixels of the Coding Unit (CU) block and finding a color from the neighboring pixels. Then, the encoding end transmits the index corresponding to the neighboring pixels of the one pixel to the decoding end. The technical concept of the palette mode is to search for one or more colors to represent the pictures in the coding unit block currently being encoded, and to use the index corresponding to the colors to each pixel in the coding unit. Index number. The encoding end uses the index corresponding to the colors to create an index map, and transmits one or more representative colors and an index of the color corresponding to each pixel in the index map to the decoding end. From this, it can be seen that in the above-described palette mode, if a plurality of colors are used to represent the screen of the coding unit block currently being encoded, At that time, it is necessary to transmit a plurality of representative colors and an index corresponding to the color of each pixel, thereby causing a decrease in coding efficiency. Accordingly, how to improve the performance of the coding to reduce unnecessary transmission and calculation in the coding operation has become a top priority.

The present disclosure provides an encoding method and a decoding method, and a codec system, an encoder and a decoder using the same, which can effectively improve the encoding performance of the screen video encoding technology.

An exemplary embodiment of the present disclosure provides an encoding method. The encoding method includes: receiving a first coding unit of a picture, the first coding unit having a plurality of pixels in an L×L matrix, and L being a positive integer. The encoding method further includes: selecting two pixels in the plurality of pixels in the picture as the first index pixel and the second index pixel, wherein the color of the first index pixel is different from the second index pixel s color. The encoding method also includes: indexing each pixel in the first coding unit to generate an index map, wherein the color of each pixel of the first coding unit in the index map is corresponding to the first index pixel The index value or the index value corresponding to the second index pixel is presented. The encoding method further includes: generating an encoded value corresponding to the first coding unit according to the index map, and transmitting the encoded value to the decoding end, wherein only the index value of the first pixel corresponding to the first coding unit is in the index map is Recorded in the encoded value.

An exemplary embodiment of the present disclosure provides a decoding method, where the decoding method includes: receiving an encoding value corresponding to a first coding unit, where the first coding unit has A plurality of pixels arranged in an L×L matrix, and L is a positive integer. The decoding method further includes: reconstructing an index map corresponding to the first coding unit according to an index value, at least one copy mode, and at least one running character value of the code value, where the received code value is only for the index map. The index value of the first pixel of the first coding unit is decoded. The decoding method further includes: obtaining a color of the first index pixel and a color of the second index pixel, and reconstructing according to the color of the first index pixel, the color of the second index pixel, and the plurality of index values of the index map. A plurality of pixels of a coding unit, wherein a color of the first index pixel is different from a color of the second index pixel.

An exemplary embodiment of the present disclosure provides an encoder, where the encoder includes an encoding module, a color selection module, an index setting module, and an index map establishing module. The encoding module receives a first coding unit of a picture, the first coding unit having a plurality of pixels in the form of an L×L matrix, and L being a positive integer. The color selection module selects two pixels in the plurality of pixels of the first coding unit as a first index pixel and a second index pixel, and the color of the first index pixel is different from the second index picture. The color of the prime. The index map establishing module indexes each pixel in the first coding unit to generate an index map, and the color of each pixel of the first coding unit in the index map is corresponding to the first index pixel. The index value or the index value corresponding to the second index pixel is presented. Further, only the index value of the first pixel corresponding to the first coding unit in the index map is recorded in the code value. The encoding module then passes the encoded value to the decoder.

An exemplary embodiment of the present disclosure provides a decoder, where the decoder includes: an encoded value receiving module and a decoding module. The coded value receiving module receives the corresponding first An encoding value of the coding unit, and the first coding unit has a plurality of pixels in the form of an L×L matrix, where L is a positive integer. The decoding module reconstructs an index map corresponding to the first coding unit according to an index value, at least one copy mode, and at least one running character value in the encoded value, and the received encoded value is only for the first coding unit in the index map. The index value of the first pixel is decoded. In addition, the decoding module obtains the color of the first index pixel and the color of the second index pixel, and reconstructs according to the color of the first index pixel, the color of the second index pixel, and multiple index values of the index map. A pixel of the first coding unit, wherein a color of the first index pixel is different from a color of the second index pixel.

An exemplary embodiment of the present disclosure provides a codec system, where the codec system includes an encoder and a decoder. The encoder receives a first coding unit of a picture, the first coding unit having a plurality of pixels in the form of an L x L matrix, and L being a positive integer. Then, the encoder selects two pixels in the plurality of pixels in the picture as a first index pixel and a second index pixel, and the color of the first index pixel is different from the second index picture. The color of the prime. In addition, the encoder indexes each pixel in the first coding unit to generate an index map, wherein the color of each pixel of the first coding unit in the index map is corresponding to the first index pixel. The index value or the index value corresponding to the second index pixel is presented. The index value of only the first pixel corresponding to the first coding unit in the index map is recorded in the encoded value. Also, the encoder will pass the encoded value to the decoder.

Based on the above, the coding method and decoding method and the codec system, the encoder and the decoder using the same according to the exemplary embodiments of the present disclosure can be The index value of the first pixel in the pixel corresponding to the coding unit is transmitted to effectively reduce the amount of transmission during the coding operation, thereby greatly reducing the time required for the coding operation to improve the coding performance.

The above described features and advantages of the present invention will be more apparent from the following description.

100‧‧‧ Codec Chip

102, 130, 150‧‧‧ storage circuits

104, 140, 160‧‧‧ processor circuits

106‧‧‧Buffered memory

110‧‧‧Encoder

120‧‧‧Decoder

112‧‧‧Code Module

114‧‧‧Color selection module

116‧‧‧ index setting module

118‧‧‧Index map creation module

122‧‧‧Code value receiving module

124‧‧‧Decoding module

200‧‧‧ first coding unit

202, 204, 206, 208, 210, 230, 250‧ ‧ pixels

220, 1220‧‧‧ at least one second coding unit

1202, 1204‧‧‧second coding unit

300‧‧‧ pixel pair

302‧‧‧Value field

304‧‧‧ pixels for the field

500, 900‧‧‧ index map

600‧‧‧ code value

610, 620, 640, 660, 670‧‧‧ copy mode to the left

630, 650‧‧‧up copy mode

612‧‧ ‧ index map of the first row and the first column index

616, 626, 636, 646, 656, 666, 676‧‧‧ displacements

618‧‧‧ running characters

60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75‧‧ ‧ pixels

1000, 1200-1, 1200-2‧‧‧ adjacent range

Steps of the S701, S703, S705, S707‧‧ ‧ encoding methods

S1001, S1003, S1005‧‧‧ steps of the decoding method

1102, 1104, 1106, 1108, 1112, 1114, 1116, 1302, 1304, 1306, 1308, 1310, 1312, 1314, 1316‧‧ ‧ cluster

C0, C1, C2, C3, C4, C5, C6‧‧‧ colors

FIG. 1A is an encoder according to a first exemplary embodiment of the present disclosure.

FIG. 1B is a diagram illustrating a decoder according to a first exemplary embodiment of the disclosure.

FIG. 1C is a codec wafer according to a first exemplary embodiment of the present disclosure.

FIG. 2A and FIG. 2B are schematic diagrams showing an image encoding operation according to a first exemplary embodiment of the present disclosure.

FIG. 3 is an example of a pixel pair table according to a first exemplary embodiment of the present disclosure.

FIG. 4 is an example of setting index values according to the first exemplary embodiment of the disclosure.

FIG. 5 is an example of establishing an index map according to the first exemplary embodiment of the disclosure.

FIG. 6A and FIG. 6B are diagrams showing an example of generating encoded values according to the first exemplary embodiment of the present disclosure.

FIG. 7 is a flowchart of an encoding method according to a first exemplary embodiment of the disclosure. Figure.

8A and 8B are code diagrams of codecs according to the first exemplary embodiment of the disclosure.

FIG. 9A is a code diagram of scanning a coding unit by using a leftward copy mode as an example according to the first exemplary embodiment of the disclosure.

FIG. 9B is a code diagram of scanning a coding unit by taking an upward copy run mode as an example according to the first exemplary embodiment of the present disclosure.

FIG. 10A to FIG. 10G are diagrams showing an example of reconstructing an index map according to an encoded value according to a first exemplary embodiment of the present disclosure.

FIG. 11 is a flowchart of a decoding method according to a first exemplary embodiment of the disclosure.

FIG. 12 is a schematic diagram of an image encoding operation according to a second exemplary embodiment of the present disclosure.

13A and FIG. 13B are schematic diagrams of pixel group operation according to a second exemplary embodiment of the present disclosure.

FIG. 14 is a schematic diagram of an image encoding operation according to a third exemplary embodiment of the present disclosure.

15A and FIG. 15B are schematic diagrams of pixel group operation according to a third exemplary embodiment of the present disclosure.

[First Exemplary Embodiment]

FIG. 1A is an encoder according to a first exemplary embodiment of the present disclosure.

Referring to FIG. 1A , the encoder 110 includes an encoding module 112 , a color selection module 114 , an index setting module 116 , an index map establishing module 118 , a storage circuit 130 , and a processor circuit 140 .

In the present exemplary embodiment, the storage circuit 130 is configured to store various data, code, or images to be processed and processed. For example, the storage circuit 130 may be a storage medium such as a memory or a Hard Disk Drive (HDD), and is not limited thereto. The processor circuit 140 is used to control the overall operation of the encoder 110. For example, the processor circuit 140 may be a central processing unit (CPU), a micro-processor, or an embedded controller, and the disclosure is not limited. The processor circuit 140 is coupled to the storage circuit 130 and configured to control the encoding module 112, the color selection module 114, the index setting module 116, and the index map creation module 118 to perform an encoding operation.

The encoding module 112 is configured to receive a coding unit (hereinafter referred to as a first coding unit) in a picture, and the first coding unit has a plurality of pixels arranged in an L×L matrix, where L is a positive integer. Specifically, under the standard of H.265/HEVC, a coding tree unit (CTU) is used as the maximum processing block when coding unit, and the size of the coding tree unit is usually set to 64×. Block of 64. The coding unit may then be smaller or equal to the block size of the coding tree unit. For example, the coding unit is a square rectangle and its size may be 64x64, 32x32, 16x16 and 8x8 blocks. It should be noted that the coding unit and the unit of the size of the adjacent range in the exemplary embodiment of the disclosure are all pixels. In this example In the embodiment, for convenience of explanation, a block having a size of 4 × 4 of the first coding unit will be assumed below.

The color selection module 114 is configured to select two pixels of different colors as the first index pixel and the second index pixel from the plurality of pixels of the first coding unit received by the encoding module 112. In an embodiment, the encoding module 112 selects two pixels from the plurality of pixels in the vicinity of the first encoding unit 200 as the first index pixel and the second index pixel, and the encoder 110 further includes The pixel creation module (not shown), the pixel pair table creation module will establish a pixel pair table to record the recognition value and the pixel pair corresponding to the plurality of pixels, wherein the pixel pair table is established. The module record identification value and pixel pair embodiment will be described in detail later. However, the disclosure is not limited thereto. For example, in another exemplary embodiment, the encoding module 112 may select two pixels from all the pixels in the picture as the first index pixel and the second index pixel. At present, video image applications use color display, and each pixel in the picture is composed of three coding components. For example, each pixel is encoded by YUV color coding method or RGB color model. And being presented. Among them, the YUV color coding method is used to compile a color space, where "Y" indicates brightness (Luminance, Luma), and "U" and "V" indicate chromaticity and concentration (Chrominance, Chroma). The RGB color model is an additive color model for adding the colors of the red, green, and blue primary colors in different proportions to produce a variety of color lights. For example, the YUV color coding method focuses on the sensitivity of vision to brightness, while the RGB color model focuses on the perception of color by the human eye. It should be noted that in the exemplary embodiment of the disclosure, the selected two different color pixels are actually divided. It is not composed of the three coding components.

The index setting module 116 is configured to set an index value corresponding to the first index pixel and an index value corresponding to the second index pixel.

The index map creation module 118 is configured to index each pixel in the first coding unit using a two-color mode/bi-color mode to generate an index map corresponding to the first coding unit. However, the disclosure is not limited thereto. For example, in another exemplary embodiment, the index map establishing module 118 generates an index number for each pixel in the first coding unit by using a palette mode. An index map corresponding to the first coding unit. In particular, the color of each pixel of the first coding unit in the established index map is presented with an index value corresponding to the first index pixel or an index value corresponding to the second index pixel.

In the present exemplary embodiment, the encoding module 112 generates an encoded value corresponding to the first coding unit according to the index map established by the index map establishing module 118.

After completing the above encoding, the encoder 110 may transmit the encoded data to the decoder for decoding. For example, the encoder 110 is implemented in the image transmitting terminal, and the decoder is implemented in the image receiving terminal, wherein the encoder and the decoder can communicate by wire or wirelessly.

FIG. 1B is a diagram illustrating a decoder according to a first exemplary embodiment of the disclosure.

Referring to FIG. 1B, the decoder 120 includes an encoded value receiving module 122, a decoding module 124, a storage circuit 150, and a processor circuit 160. The storage circuit 150 is used to store various data, code or images to be processed and processed. For example, the storage circuit 150 may be a storage medium such as a memory or a hard disk, and is not limited thereto. Processor power The path 160 is coupled to the storage circuit 150 and is used to control the overall operation of the decoder 120. In particular, processor circuit 160 controls encoded value receiving module 122 and decoding module 124 to perform the decoding operation. For example, the processor circuit 160 may be a central processing unit (CPU), a micro-processor, or an embedded controller, and the disclosure is not limited.

With respect to the encoder 110, the encoded value receiving module 122 of the decoder 120 receives the encoded value from the encoding module 112 of the encoder 110 and the decoding module 124 restores the corresponding encoding unit according to the received encoded value. For example, the code value receiving module 122 receives the identification value corresponding to the color of each set of pixel pairs or the color of the first index pixel and the color of the second index pixel, and the code value corresponding to the first coding unit, and The decoding module 124 reconstructs an index map corresponding to the first coding unit according to the coded value, and reconstructs multiple first coding units according to the color of the first index pixel, the color of the second index pixel, and the plurality of indexes of the index map. Picture.

It is worth mentioning that the above encoder and decoder are respectively implemented in different terminals, and the materials required for each other are transmitted through the network. However, the disclosure is not limited thereto. In another exemplary embodiment, the encoder and decoder may be implemented in the same wafer or system. For example, in an example where the encoder and the decoder are respectively implemented in different terminals, the encoder and the decoder are two separate devices, and the encoder transmits the compressed data to the decoder, and the decoder receives the code. Compressed data from the device. In the example where the encoder and the decoder are implemented in the same chip or system, the encoder and the decoder are arranged in the same device, so the encoder transmits the compressed data to the hard disk of the device itself. (eg, storage circuit 102), and The decoder will receive the compressed data from the hard disk in the same device.

FIG. 1C is a codec wafer according to a first exemplary embodiment of the present disclosure.

Referring to FIG. 1C, the codec wafer 100 (also referred to as a codec system) includes a storage circuit 102, a processor circuit 104, a buffer memory 106, an encoder 110, and a decoder 120.

The storage circuit 102 is configured to store various data, code or images to be processed and processed. For example, the storage circuit 102 may be a storage medium such as a memory or a hard disk, and is not limited thereto.

The processor circuit 104 is used to control the overall operation of the codec wafer 100. For example, processor circuit 104 will issue an instruction to storage circuit 102 to perform an operation of encoding and decoding the image by encoder 110 and decoder 120. For example, the processor circuit 104 can be a central processing unit (CPU), a micro-processor, or an embedded controller, and the disclosure is not limited.

The buffer memory 106 is coupled to the processor circuit 104 and is used to temporarily store data. In the exemplary embodiment, the buffer memory 106 is a static random access memory (SRAM). It should be understood that the disclosure is not limited thereto. In another exemplary embodiment, the buffer memory 106 may be a dynamic random access memory or other memory.

The storage circuit 102 is coupled to the processor circuit 104 and the buffer memory 106. The operation of the encoder 110 and the decoder 120 are the same as those of the encoder and decoder shown in Figs. 1A and 1B, respectively. For example, the encoder 110 includes an encoding module 112, The color selection module 114, the index setting module 116, and the index map building module 118. The decoder 120 includes an encoded value receiving module 122 and a decoding module 124.

It should be noted that the encoder and the decoder in the disclosure are implemented by a software module or a code. For example, the storage circuit 102 stores the encoding module, the color selection module, the index setting module, and the index map. A module, a pixel pair module creation module, a code value receiving module, and a decoding module are created, and when the codec chip 100 is enabled, the software code is loaded from the storage circuit 102 to the buffer memory 106. And the processor circuit 102 performs the functions of the operation coding module, the color selection module, the index setting module, the index map creation module, the pixel pair table creation module, the code value receiving module, and the decoding module. However, the disclosure is not limited thereto. For example, in another exemplary embodiment of the disclosure, the codec chip, the encoder, and the decoder may be implemented by a hardware circuit. For example, the above coding module, color selection module, index setting module, index map creation module, pixel pair table creation module, code value receiving module, and decoding module can be used as a coding circuit and color. A selection circuit, an index setting circuit, an index map establishing circuit, an encoding value receiving circuit, and a decoding circuit.

In order to more clearly describe the operation of the encoder 110, the decoder 120, and the codec wafer 100, an example will be described below with reference to the codec wafer 100 of FIG. 1C.

FIG. 2A and FIG. 2B are schematic diagrams showing an image encoding operation according to a first exemplary embodiment of the present disclosure.

Please refer to FIG. 2A. Here, the dual color mode is taken as an example, and the coding mode is assumed. The size of the first coding unit 200 in a picture received by the group 112 is L x L, where L is a positive integer. For example, the encoding module 112 selects two pixels as the first index pixel and the second index pixel from the plurality of pixels in the vicinity of the first encoding unit 200. However, the disclosure is not limited thereto. For example, in another exemplary embodiment, the encoding module 112 may select two pixels from all the pixels in the picture as the first index pixel and the second index pixel. In this exemplary embodiment, the neighboring range includes a plurality of pixels adjacent to the first encoding unit 200 in the at least one encoding unit 220 (hereinafter referred to as at least one second encoding unit 220) adjacent to the first encoding unit 200 (hereinafter Called the third pixel). It should be noted that, in the decoding order of the picture where the first coding unit 200 and the at least one second coding unit 220 are located, at least one second coding unit 220 is the coding unit that has been decoded before the first coding unit 200 is decoded. In other words, the proximity range does not include the coding unit currently being coded and/or the area that will be decoded after the coding unit currently being encoded in the decoding process. However, the disclosure does not limit the area of the proximity range. For example, in another exemplary embodiment, the proximity range may also include coding units that are currently to be encoded and/or undecoded areas in the picture.

Specifically, the third pixels are respectively a pixel 202 and a pixel 204 adjacent to an upper edge and a left edge of the first row of pixels of the first row of the first coding unit 200. The pixel 206 adjacent to the upper edge of the first column of pixels of the Lth row of the first coding unit 200 is adjacent to the pixel 208 of the left edge of the first row and the Lth column of pixels of the first coding unit 200 and Corresponding to the pixel 210 in the upper left corner of the first row and the first column of the first coding unit 200.

In an exemplary embodiment in which the dual color mode is taken as an example, the encoder 110 further includes a pixel pair table creation module (not shown), and the pixel pair table creation module establishes a pixel pair table to record corresponding to the above. The recognition value of the third pixel and the pixel pair. For example, the pixel pair module creation module generates a plurality of pixel pairs according to the third pixels (ie, the pixels 202, the pixels 204, the pixels 206, the pixels 208, and the pixels 210), and correspondingly The recognition value of each pixel pair and the color of each group of pixels corresponding to the recognition value are recorded in the pixel pair table. It should be noted that in the exemplary embodiment, the pixel pair table creation module generates a plurality of pixel pairs by using a set of pixels 202, pixels 204, pixels 206, pixels 208, and pixels 210. However, the disclosure is not limited thereto. For example, in another exemplary embodiment, the proximity range may include a proximity range 1000 (shown in FIG. 2B) adjacent to the first coding unit 200 in the at least one second coding unit 220 adjacent to the first coding unit 200. Therefore, the plurality of third pixels in the adjacent range 1000 may be the pixels 210 corresponding to the upper left corner of the first row and the first column of pixels of the first encoding unit 200, and adjacent to the first in the adjacent range 1000. Any one of the pixels 230 of the left edge of the encoding unit 200 and any one of the pixels 250 adjacent to the upper edge of the first encoding unit 200 within the adjacent range 1000. Therefore, the pixel-pairing module can generate a plurality of pixel pairs by using a set of pixels 210, pixels 230, and pixels 250. In addition, in another exemplary embodiment in which the palette mode is taken as an example, the encoder 110 directly selects two pixels from the plurality of pixels in the first encoding unit 200 as the first index pixel and the second index. Picture.

FIG. 3 is an example of a pixel pair table according to a first exemplary embodiment of the present disclosure.

Referring to FIG. 2A and FIG. 3, the pixel pair table creation module generates a plurality of pixel pairs according to the pixel 202, the pixel 204, the pixel 206, the pixel 208, and the pixel 210, and pairs the pixel pairs with the color thereof. Recorded in the pixel pair field 304 of the pixel pair table 300. In addition, the pixel pair table creation module also records the identification value (0~9) corresponding to each pixel pair in the identification value field 302. For example, the recognition value of the pixel pair identification value 0 in the table 300 corresponds to the pixel pair whose pixel is the pixel 208 and the pixel 206, and the color of the pixel 208 and the pixel 206 in the pixel pair. They are C1 and C2 respectively. And so on, each recognition value will correspond to its pixel pair and the color it represents. Accordingly, the color selection module 114 can select one of the pixel pairs according to the pixel pair table 300, and the two pixels in the pixel pair selected by the color selection module 114 are set as the first index pixel. With the second index pixel.

FIG. 4 is an example of setting index values according to the first exemplary embodiment of the disclosure.

Referring to FIG. 4, in the exemplary embodiment, the color selection module 114 selects a pixel pair (ie, pixel 208 and pixel 204) corresponding to the identification value with a recognition value of 3 as the first index pixel 208 and The second index pixel 204. Therefore, the index setting module 116 sequentially sets the index value corresponding to the first index pixel 208 to 0 and the index value corresponding to the second index pixel 204 to 1. Thereafter, in the operation of the encoding module 112 to transmit the encoded value to the decoder 120, the encoding module 112 also transmits the identification value (ie, 3) to the decoder 120.

FIG. 5 is an example of establishing an index map according to the first exemplary embodiment of the disclosure.

Referring to FIG. 5, afterwards, the index map establishing module 118 can use the double according to the index value corresponding to the first index pixel 208 (ie, 0) and the index value corresponding to the second index pixel 204 (ie, 1). The color mode indexes each pixel in the first encoding unit 200 to generate an index map 500. In other words, the color of each pixel of the first coding unit 200 in the index map 500 is an index value corresponding to the first index pixel 208 (ie, 0) or an index value corresponding to the second index pixel 204 (ie, 1) to present. In particular, in the present exemplary embodiment, it is assumed that the size of the first coding unit 200 is 4×4, and therefore, the index value of each pixel corresponding to the first coding unit 200 in the index map 500 is in the form of a 4×4 matrix. arrangement.

In addition, in the exemplary embodiment, in the operation of generating the code value corresponding to the first coding unit 200 according to the index map 500, the coding module 112 only records the pixels corresponding to the first coding unit 200 in the coded value. The index value of the first pixel of the first pixel unit is the same as the index value of the index of the first row and the first column of the index map 500. .

FIG. 6A and FIG. 6B are diagrams showing an example of generating encoded values according to the first exemplary embodiment of the present disclosure.

Referring to FIG. 6A and FIG. 6B, after the index map creation module 118 indexes each pixel in the first coding unit to generate an index map 500, the encoding module 112 generates a corresponding first coding unit according to the index map 500. The encoded value of 200 is 600. In the present exemplary embodiment, the encoded value 600 includes an index value corresponding to the first pixel of the pixels of the first encoding unit 200 (ie, an index value of the index of the first row and the first column of the index map 500). , copy mode (CodeMode) and running characters value. For example, since the index value of one pixel (ie, pixel 61) following the first pixel (ie, pixel 60) in the index map 500 is the same as the index value of the first pixel, The index value of one pixel (ie, pixel 63) following the third pixel (ie, pixel 62) is the same as the index value of the third pixel, and the index value of the first pixel Different from the index value of the third pixel. Therefore, the encoding module 112 uses the left copy run mode (CopyLeftMode) 610, the first row and the first column index (Index) 612 (ie, 0) of the index map 500 and the value of the run character in the code value 600. 618 is used to describe the first pixel (ie, pixel 60) of the first coding unit 200 and the succeeding 1 pixel (ie, pixel 61). For example, the value 618 of the running character may include the number of displacements (1). 616. In addition, the encoding module 112 uses the left copy running mode 620 and the displacement number (1) 626 in the encoded value 600 to describe the third pixel in the first encoding unit 200 following the one pixel (ie, , pixel 62) and a subsequent pixel (ie, pixel 63).

It is worth mentioning that, in the present exemplary embodiment, the index map 500 established by the index map creation module 118 is generated by indexing each pixel of the first coding unit 200 in a dual color mode. Therefore, the code values for describing the pixels 62 and the pixels 63 corresponding to the first coding unit 200 need only include the leftward copy mode 620 and the number of displacements (1) 626. In other words, since the index value of the first pixel in the index map 500 (ie, the pixel 60) is different from the index value of the third pixel (ie, the pixel 62), when the decoder 120 receives the leftward When the run mode 620 and the number of shifts (1) 626 are copied, it is only necessary to know that the index value of the third pixel is 1 according to the index value (ie, 0) of the first pixel in the index map 500.

In the present exemplary embodiment, since the first row of the corresponding index map 500 is the second The index of the column index (ie, pixel 64) and the successive two pixels (ie, pixel 65 and pixel 66) are respectively the same as the index of the first row and the first column of the corresponding index map 500. The index of the pixel (ie, pixel 60) and the following two pixels (ie, pixel 61 and pixel 62). Therefore, the encoding module 112 will use the upward copy running mode (CopyAboveMode) 630 and the displacement number (2) 636 in the encoded value 600 to describe the drawing of the first row and the second column index of the corresponding index map 500 in the first encoding unit 200. Prime (ie, pixel 64) and the following two pixels (ie, pixel 65 and pixel 66). In particular, when the decoder 120 receives the upward copy run mode 630, the decoder 120 learns the picture of the first row and the second column index of the corresponding index map 500 according to the upward copy run mode 630 and the displacement number (2) 636. The prime (ie, pixel 64) and the two pixels after the continuation (ie, pixel 65 and pixel 66) have the same index value as the pixel of the first row and the first column of the corresponding index map (ie, , pixel 60) and the index value of two consecutive pixels (ie, pixel 61 and pixel 62).

The index value of the pixel (ie, pixel 67) of the index of the fourth row and the second column of the corresponding index map 500 is different from the pixel of the index of the fourth row and the first column of the corresponding index map 500 (ie, pixel 63). Index value, and the two pixels following the pixel of the fourth row and second column index of the corresponding index map 500 (ie, pixel 67) (ie, pixel 68 and pixel 69) have the same index value. The index value of the pixel (ie, pixel 67) indexed in the fourth row and the second column of the corresponding index map. Therefore, the encoding module 112 will use the leftward copy running mode 640 and the displacement number (2) 646 in the encoded value 600 to describe the pixels of the fourth row and the second column index of the corresponding index map 500 in the first encoding unit 200 ( That is, the pixel 67) and the following two pixels (that is, the pixel 68 and the pixel 69). In other words, when the decoder 120 When the leftward copy mode 640 and the number of displacements (2) 646 are received, the corresponding index map 500 can be known only according to the index value (ie, 1) of the index of the fourth row and the first column of the corresponding index map 500. The index of the 4th row and 2nd column index is 0, and the 2 pixels (i.e., pixel 68 and pixel 69) following the pixel 67 are also 0.

In addition, since the pixels of the index of the third row and the third column of the corresponding index map 500 (ie, the pixels 70) and the pixels that follow the pixels of the index of the third row and the third column of the corresponding index map 500 ( That is, the index values of the pixel 71, the pixel 72, and the pixel 73) are respectively the same as the three pixels after the pixel 66 and the succeeding pixel (that is, the pixel 67, the pixel 68, and the pixel 69). Index value. Therefore, the encoding module 112 uses the upward copy running mode 650 and the displacement number (3) 656 to describe the pixels of the third row and third column index of the corresponding index map 500 in the first encoding unit 200 (ie, the pixel 70). And the following three pixels (ie, pixel 71, pixel 72 and pixel 73). In other words, when the decoder 120 receives the upward copy run mode 650, the decoder 120 learns the pixels of the third row and the third column index of the corresponding index map 500 according to the upward copy run mode 650 and the displacement number (3) 656. (ie, the pixel 70) and the successive three pixels (ie, the pixel 71, the pixel 72 and the pixel 73) have the same index value as the pixel of the third row and the second column index of the corresponding index map. (ie, pixel 66) and the index values of the three pixels that are connected (ie, pixel 67, pixel 68, and pixel 69).

In the present exemplary embodiment, the index value of the pixel (ie, pixel 74) of the index of the third row and the fourth column of the corresponding index map 500 is different from the pixel of the index of the third row and the third column of the corresponding index map 500. (ie, pixel 70) index value, and subsequent to the pixel corresponding to the index of the third row and fourth column of the corresponding index map 500 (ie, pixel 74) The index value of the prime (ie, pixel 75) is not the same as the index value of the pixel 74. Therefore, the encoding module 112 will use the leftward copy running mode 660 and the displacement number (0) 666 in the encoded value 600 to describe the pixels of the third row and the fourth column index of the corresponding index map 500 in the first encoding unit 200 ( That is, the pixel 74). When the decoder 120 receives the leftward copy mode 660 and the number of displacements (0) 666, it only needs to be based on the index value (ie, 1) of the index of the third row and the third column of the corresponding index map 500. The index of the third row and the fourth column index of the corresponding index map 500 is 0.

Thereafter, the index value of the pixel (i.e., pixel 75) of the index of the fourth row and the fourth column of the corresponding index map 500 is different from the index value of the pixel 74. Therefore, the encoding module 112 will use the left copy run mode 670 and the shift number (0) 676 in the encoded value 600 to describe the pixels of the fourth row and fourth column index of the corresponding index map 500 in the first encoding unit 200. That is, when the decoder 120 receives the leftward copy mode 670 and the number of shifts (0) 676, only the index value (ie, 0) of the index of the fourth row and the third column of the corresponding index map 500 is required, that is, It can be known that the index of the pixel of the fourth row and the fourth column index of the corresponding index map 500 is 1. Based on the above, it can be seen from the example of generating the encoded value shown in FIG. 6A and FIG. 6B that the encoded value includes the index value of the first pixel among the pixels of the first encoding unit 200, at least one copy mode, and at least The value of a run character.

It is worth mentioning that, in the operation that the encoding module 112 generates the encoded value 600 corresponding to the first encoding unit 200 according to the index map 500 and transmits the encoded value 600 to the decoder 120, the encoding module 112 only needs to record and transmit. The index value corresponding to the first pixel among the plurality of pixels of the first coding unit 200, the decoder 120 The index value of the pixel currently being decoded can be determined according to the other information in the encoded value 600 and the index value of the pixel in the first encoding unit 200, thereby effectively reducing the transmission amount and improving the encoding operation. Encoding and decoding performance.

In summary, in the embodiment in which the dual color mode is taken as an example, the encoding module 112 transmits the encoded value and the identification value to the decoder, and according to the above, the encoded value may include the pixels of the first encoding unit 200. The index value of the first pixel, at least one copy mode, and a value of at least one run character.

It is worth mentioning that the disclosure is not limited to indexing each pixel in the first coding unit using the above two-color mode. For example, in another exemplary embodiment, each pixel in the first coding unit is indexed using a palette mode to generate an index map corresponding to the first coding unit. Specifically, in the exemplary embodiment in which the palette mode is taken as an example, the encoder 110 does not establish the pixel pair table of FIG. 3 above. For example, the encoder 110 directly encodes the value, the first index pixel. The color of the second index is directly transmitted to the decoder 120 instead of transmitting an identification value corresponding to the color of the first index pixel and the color of the second index picture. And, the encoded value includes an index value of the first pixel among the pixels of the first encoding unit 200, at least one copy mode, and a value of at least one run character.

FIG. 7 is a flowchart of an encoding method according to a first exemplary embodiment of the disclosure.

Referring to FIG. 7, in step S701, the encoder 110 receives a first coding unit of a picture, wherein the first coding unit has a plurality of pixels in the form of an L×L matrix, and L is a positive integer.

In step S703, the encoder 110 selects two pixels as the first index pixel and the second index pixel among the plurality of pixels, and the color of the first index pixel is different from the color of the second index pixel. For example, in the dual color mode, the encoder 110 creates a pixel pair table and transmits an identification value corresponding to the selected two pixels to the decoder 120 according to the pixel pair table. In the palette mode, the encoder 110 directly transmits the color of the two pixels to the decoder 120.

In step S705, the encoder 110 performs index numbering on each pixel in the first coding unit to generate an index map, wherein the color of each pixel of the first coding unit in the index map is drawn by the corresponding first index. The index value of the prime or the index value corresponding to the second index pixel is presented.

In step S707, the encoder 110 generates an encoded value corresponding to the first coding unit according to the index map, wherein only the index value of the first pixel in the pixel corresponding to the first coding unit is recorded in the encoded value, that is, Only the index value of the first pixel among the pixels corresponding to the first coding unit in the index map is recorded in the code value.

8A and FIG. 8B are decoded code diagrams according to the first exemplary embodiment of the disclosure.

Referring to FIG. 8A and FIG. 8B, in the decoding operation, the decoder 120 may decide whether to use the dual color mode for decoding according to the equation in the code shown in FIG. 8A. The parameter "slice_bi_sample_mode_enable_flag" is used to indicate whether to use the dual color mode. For example, when the value of "slice_bi_sample_mode_enable_flag" is set to 1, the decoder 120 uses the dual color mode to decode the picture currently being decoded. Work. Next, the decoder 120 determines whether to use the dual color mode to decode the coding unit currently to be decoded according to the equation in the code shown in FIG. 8B. For example, when the value of "bi_sample_flag" is set to 1, the decoder 120 uses the dual color mode to decode the coding unit currently to be decoded. It is to be noted that the disclosure is not limited thereto. For example, in another exemplary embodiment, the decoder 120 is an operation of decoding a picture currently to be decoded using a palette mode. In particular, the value of the above "slice_bi_sample_mode_enable_flag" may also be preset to 1, and when the preset is 1, the decoder 120 may omit the step of determining the value of "slice_bi_sample_mode_enable_flag" in the decoding operation.

Referring to FIG. 8B again, in the operation of the decoder 120 reconstructing the index map according to the encoded value, the decoder 120 is based on the index value of the index elements in the first row and the first column, the copy mode (upward copy run mode or copy to the left) Run mode), run the value of the character to reconstruct the index map, and the decoder 120 decides to reconstruct the index map using the up copy run mode or the left copy run mode according to the equation in the code shown in FIG. 8B. Specifically, when the parameter "palette_run_type_flag" is set to 1, the decoder 120 uses the up copy run mode to reconstruct the pixels in the index map, and determines the number of shifts according to the parameter "palette_run", in which the up copy run mode is used. The reconstructed pixels will be the same as at least two pixels of the corresponding number of displacements in a column above the index map. Conversely, when the parameter "palette_run_type_flag" is set to 0, the decoder 120 uses the leftward copy mode to describe the pixels in the coding unit being encoded, and determines the number of displacements according to the parameter "palette_run", wherein the left is used. The number of displacements after the pixel reconstructed in the copy mode and the index map are continued after this pixel At least one of the pixels is the same. Further, as described above, in the present disclosure, the color of the pixels in the coding unit in the established index map is presented with the index values of the two index pixels. For example, the parameter "bi_sample_idx" in the equation is an index value for indicating a plurality of candidate index pixels, and the parameter "palette_index" is used to represent the above two index pixels selected from a plurality of candidate index pixels. Index value. In particular, in the disclosure, the encoder 110 transmits the index value of the index pixel of the first row and the first column in the index map to the decoder 120 through the parameter “palette_index”, according to which the decoder 120 can be The other information in the encoded value and the index value of the decoded pixel in the coding unit determine the index value of the pixel currently being decoded.

FIG. 9A is a code diagram of scanning a coding unit by using a leftward copy mode as an example according to the first exemplary embodiment of the present disclosure. In this exemplary embodiment, it is assumed that a pixel currently being decoded is used. The copy mode is a copy mode to the left, wherein the copy mode is represented by the parameter "CodeMode" in Fig. 9A, and the left copy run mode in the copy mode is represented by the parameter "CopyLeftMode" in Fig. 9A.

Referring to FIG. 9A, in the exemplary embodiment, the decoding module 124 of the decoder 120 is not limited to scanning and decoding the coding units in the picture by using a specific scanning manner. For example, in an exemplary embodiment, the decoding module 124 can scan and decode the coding units in the picture using Z-scan (Z-scan), and in another exemplary embodiment, the decoding module 124 is used horizontally. A horizontal traverse scan or a vertical traverse scan scans and decodes coding units in a picture. Specifically, the code shown in Figure 9A is correct. The operation of scanning and decoding the coding unit in the picture should be performed by converting the coordinates of the horizontal cross scan and the coordinates of the corresponding vertical cross scan into the coordinates of the corresponding Z-axis scan. Referring to FIG. 9A, the pixel currently being decoded is used. The copy mode is an example of copying the run mode to the left (ie, "CopyLeftMode").

In this exemplary embodiment, the index value of each pixel corresponding to one coding unit in the index map is arranged in an L×L matrix form. Here, as shown in FIG. 9 , it is assumed that the index of the index map has been scanned. The number is c. For example, when the decoding module 124 decodes the pixels of the first index scanned in the corresponding index map (that is, when c=1), the decoding module 124 is based on the first index of the index map and the value of the running character. Rebuild the index map. In addition, when the decoding module 124 decodes the pixels of the c-th index scanned in the corresponding index map (for example, when 1<c<=L), the decoding module 124 indexes the scanned c-th index. The value (ie, the index value being decoded) is converted to a coordinate (x, y), and the index value of the scanned c-1 index is converted into a coordinate (m, n). Next, the decoding module 124 reconstructs the index map according to the scanned value of the c-1 index and the running character in the index map, in particular, the value of the c-th index scanned in the index map (ie, Index(x, y)) The remainder obtained by dividing 1 by the index value of the corresponding coordinate (m, n) (ie, Index(m, n)) by dividing by 2.

In another exemplary embodiment, when the decoding module 124 decodes the pixels of the c-th index scanned in the corresponding index map (for example, when c>L), the decoding module 124 scans the index map. The c-th index is converted into coordinates (x, y), the scanned c-1th index is converted into coordinates (m, n), and the scanned c-th index is converted into coordinates (p, q). In addition, the decoding module 124 also determines that the corresponding c-1 cable The copied mode is to use the up copy run mode or the left copy run mode to decode the pixels of the c-1th index scanned in the corresponding index map. If the copy mode of the c-1th index is to use the left copy mode to decode the pixel of the c-1th index scanned in the corresponding index map, the decoding module 124 will be based on the scanned c-1. The index and the value of the running character reconstruct the index map, wherein the value of the c-th index scanned in the index map (ie, Index(x, y)) is an index value of the corresponding coordinate (m, n) (ie, Index ( m, n)) The remainder obtained by dividing by 2 and dividing by 2. On the other hand, in another exemplary embodiment, if the copy mode corresponding to the c-1th index is used to decode the c-1 index scanned in the corresponding index map by using the upward copy run mode (ie, "CopyAboveMode") When the pixel is used, the decoding module 124 reconstructs the index map according to the scanned cL index and the running character value in the index map, wherein the index of the c-th index scanned in the index map (ie, Index(x, y) )) is the remainder obtained by adding 1 to the index value of the corresponding coordinate (p, q) (ie, Index(p, q)) and dividing by 2. However, it is worth noting that the disclosure is not limited thereto.

FIG. 9B is a code diagram of scanning a coding unit in an example of an upward copy run mode according to the first exemplary embodiment of the present disclosure. In this exemplary embodiment, a pixel that is currently being decoded is assumed to be used. The copy mode is an upward copy run mode in which the copy mode is represented by the parameter "CodeMode" in Fig. 9B, and the number of shifts in the copy mode is represented by the parameter "run" in Fig. 9B. Referring to FIG. 9B, in this exemplary embodiment, since the copy mode used by the pixel currently being decoded is the upward copy run mode, when the decoding mode received by the decoding module 124 is the upward copy run mode (ie, "CopyAboveMode"), the decoding module 124 only needs The index map can be reconstructed by copying the index value of the corresponding pixel in the index map to be reconstructed according to the representative copy-up run mode and the number of displacements. For example, the decoding module 124 converts the c-th index scanned in the index map into coordinates (x, y), converts the scanned c-th index into coordinates (p, q), and according to the displacement number "run" The value of "the index of the c-th index currently scanned in the index map (ie, Index(x, y)) is set to the index value of the corresponding coordinate (p, q) (ie, Index(p, q)). Hereinafter, an example in which an index map is reconstructed based on coded values will be described with reference to FIGS. 6A and 10A to 10G.

FIG. 10A to FIG. 10G are diagrams showing an example of reconstructing an index map according to an encoded value according to a first exemplary embodiment of the present disclosure.

Referring to FIG. 10A and FIG. 6A, in the exemplary embodiment, the decoding module 124 of the decoder 120 reconstructs the index map corresponding to the first coding unit according to the code value 600 received by the code value receiving module 122. Since the index value of each pixel corresponding to the first coding unit 200 in the index map 500 is arranged in a 4×4 matrix form, and the index value of the first pixel recorded in the encoded value 600 is the index map 500. 1 row of the first column index (ie, 0). Therefore, the decoding module 124 will copy the running mode 610 according to the encoding value 600, the first row, the first column index 612 and the displacement number (1) 616 of the index map 500 in the index map 900 to be reconstructed. The index value of the first pixel of one coding unit 200 is recorded as 0, and the index value of one pixel subsequent to the first pixel is also recorded as 0.

Referring to FIG. 10B and FIG. 6A, the decoding module 124 learns that the index values of one pixel after the first pixel in the index map 900 are the same according to the left copy running mode 620 and the number of displacements (1) 626. The index value of the first pixel, followed by The index value of one pixel after the third pixel is the same as the index value of the third pixel, and the index value of the first pixel is different from the index value of the third pixel. For example, the decoding module 124 is to add the remainder of the index value (ie, 0) of the second row and the first column of the index map 500 to the first row of pixels in the third row and the first column. The index value (ie, 1). Therefore, the decoding module 124 will correspond to the index value of the third row and the first column of the first coding unit 200 in the index map 900 according to the index value of the second row and the first column of pixels. The index value of one pixel following the third pixel is recorded as 1.

Referring to FIG. 10C and FIG. 6A , the decoding module 124 then learns the index value and the connection of the pixels of the first row and the second column index of the corresponding index map 900 according to the upward copy running mode 630 and the displacement number ( 2 ) 636 . The index values of the two pixels after the pixel corresponding to the index of the first row and the second column of the index map 900 are respectively the same as the pixels of the index of the first row and the first column of the corresponding index map 900 and the contiguous index map. The index value of the two pixels after the pixel of the index in the first row and the first column of 900. For example, the decoding module 124 only needs to copy the pixels of the first row and the first column index of the corresponding index map 900 and the two pixels of the pixel after the pixel of the index of the first row and the first column of the corresponding index map 900. The value is the index value of the pixel corresponding to the first row and the second column index of the index map 900 and the index values of the two pixels following the pixel of the index of the first row and the second column of the corresponding index map 900. Therefore, the decoding module 124 maps the index value of the pixel corresponding to the first row and the second column index of the corresponding index map in the first coding unit 200 and the index of the first row and the second column of the corresponding index map 900 in the index map 900. The index values of the two pixels after the pixels are recorded as 0, 0, and 1, respectively.

Referring to FIG. 10D and FIG. 6A, the decoding module 124 learns that the index value of the pixel of the fourth row and the second column index of the corresponding index map 900 is different from the corresponding one according to the left copy running mode 640 and the displacement number (2) 646. The index value of the pixel of the index of the fourth row and the first column of the index map 900, and the index values of the two pixels following the pixel of the index of the fourth row and the second column of the corresponding index map 900 are the same as the corresponding index. The index value of the pixel of the index in the fourth row and the second column of the map 900. For example, the decoding module 124 is to use the remainder obtained by dividing the index value (ie, 1) of the fourth row and the first column of the index map 500 in the index map 500 by 2 to be the index value of the index of the fourth row and the second column. (ie, 0). Therefore, the decoding module 124 then records, in the index map 900, the index value of the pixel corresponding to the fourth row and the second column index of the corresponding index map 900 in the first encoding unit 200 as 0 and the corresponding index map 900. The index values of the two pixels after the pixels of the 4th column and the 2nd column index are also recorded as 0.

Referring to FIG. 10E and FIG. 6A, the decoding module 124 learns the pixel of the third row and the third column index of the corresponding index map 900 according to the upward copy running mode 650 and the displacement number (3) 656 in the received encoded value. The index value of the three pixels subsequent to the pixel following the index of the third row and the third column of the corresponding index map 900 is the same as the pixel of the index of the third row and the second column of the corresponding index map 900. The index values of the three pixels following the pixel of the index in the third row and the second column of the index map 900 are successively connected. For example, the decoding module 124 only needs to copy the pixels of the third row and the second column index of the corresponding index map 900 and the indices of the three pixels that follow the pixels of the third row and the second column index of the corresponding index map 900. The value is used as the index value of the pixel of the index of the third row and the third column of the corresponding index map 900 and the continuation of the corresponding index map 900. The index value of the three pixels after the pixel of the index in the third row and the third column. Therefore, the decoding module 124 sets the index value of the pixel corresponding to the index of the third row and the third column of the corresponding index map 900 in the first coding unit 200 and the third row of the corresponding index map 900 in the index map 900. The index values of the three pixels after the pixels of the column index are recorded as 1, 0, 0, and 0, respectively.

Referring to FIG. 10F and FIG. 6A , the decoding module 124 learns that the index values of the pixels of the third row and the fourth column index of the corresponding index map 900 are different according to the received left copy run mode 660 and the number of shifts (0) 666. The index value of the pixel indexed in the third row and the third column of the corresponding index map 900. For example, the decoder 120 is the index obtained by adding 1 to the index value (ie, 1) of the third row and the third column of the index map 500, and dividing by 2 to be the index value of the index of the third row and the fourth column ( That is, 0). Therefore, the decoding module 112 records the index value of the pixel corresponding to the index of the third row and the fourth column of the corresponding index map 900 in the first coding unit 200 to 0 in the index map 900.

Referring to FIG. 10G and FIG. 6A , the decoding module 124 learns the index value of the pixel of the fourth row and the fourth column index of the corresponding index map 900 according to the received left copy run mode 670 and the number of displacements (0) 676. It is different from the index value of the pixel of the index of the fourth row and the third column of the corresponding index map 900. For example, the decoder 120 is the index obtained by dividing the index value (ie, 0) of the fourth row and the third column of the index map 500 by 1 and dividing by 2 as the index value of the index of the fourth row and the fourth column ( That is, 1). Therefore, the decoding module 124 records the index value of the pixel corresponding to the fourth row and the fourth column index of the corresponding index map 900 in the first coding unit 200 to 1 in the index map 900.

In the present exemplary embodiment, the decoder 120 also records the corresponding code. The pixel of the device 110 is paired with the table 300 (as shown in FIG. 3). Therefore, the decoding module 124 receives the identification value corresponding to the first index pixel and the second index pixel received by the module 122 according to the code value. The color of the first index pixel and the color of the second index pixel are identified in the table 300. For example, the identifier value received by the code value receiving module 122 is 3. Therefore, the decoding module 124 can learn from the pixel pair table 300 that the first index pixel and the second index pixel are respectively drawn according to the identification value. The pixels 208 and the pixels 204, and the colors of the pixels 208 and 204 are C1 and C2, respectively. Thereafter, the decoding module 124 may reconstruct the plurality of pixels of the first encoding unit 200 according to the index map 900 and the color of the corresponding first index pixel and the second index pixel.

FIG. 11 is a flowchart of a decoding method according to a first exemplary embodiment of the disclosure.

Referring to FIG. 11, in step S1001, the decoder 120 receives the identification value corresponding to the color of each set of pixel pairs or the color of the first index pixel and the color of the second index pixel, and the corresponding first coding unit. The value is encoded, and the first coding unit has a plurality of pixels in the form of an L×L matrix, where L is a positive integer.

In step S1003, the decoder 120 reconstructs an index map corresponding to the first coding unit according to the index value in the encoded value, the at least one copy mode, and the value of the at least one running character, wherein the index value in the received encoded value includes only the index. The index value of the first pixel of the first coding unit in the map.

In step S1005, the decoder 120 reconstructs a plurality of pixels of the first coding unit according to the color of the first index pixel, the color of the second index pixel, and the plurality of index values of the index map, and the first index pixel The color is different from the second index pixel color.

[Second exemplary embodiment]

The encoding method and decoding method of the second exemplary embodiment and the system thereof are essentially the same as the encoding method and decoding method of the first exemplary embodiment and the system thereof, and the difference is that in the second exemplary embodiment, the statistical method is The quantized method selects two pixels as the first index pixel and the second index pixel. The system and component numbers of the first exemplary embodiment will be used below to explain the differences between the second exemplary embodiment and the first exemplary embodiment.

FIG. 12 is a schematic diagram of an image encoding operation according to a second exemplary embodiment of the present disclosure.

Referring to FIG. 12, in the same manner as the first exemplary embodiment, the encoding module 112 selects two pixels from the plurality of pixels in the vicinity of the first encoding unit 200 as the first index pixel and the second index. Prime. However, the disclosure is not limited thereto. For example, in another exemplary embodiment, the encoding module 112 may also select two pixels from all the pixels in the picture as the first index pixel and the second index pixel. It is assumed here that the size of the first coding unit 200 in a picture received by the coding module 112 is L×L, and L is a positive integer. In particular, in the present exemplary embodiment, the neighboring range includes a plurality of pixels adjacent to the first encoding unit 200 in the at least one second encoding unit 220 adjacent to the first encoding unit 200 (hereinafter referred to as a third pixel) ). Here, the range in which the plurality of third pixels belong is the proximity range 1000. That is to say, the encoding module 112 selects two pixels from the plurality of third pixels in the adjacent range 1000 as the first index pixel and the second index pixel. It is worth noting that the first coding unit 200 and at least one In the decoding order of the picture in which the two coding unit 220 is located, at least one second coding unit 220 is a coding unit that has been decoded before the first coding unit 200 is decoded. In other words, the proximity range does not include the coding unit currently being coded and/or the area that will be decoded after the coding unit currently being encoded in the decoding process. However, the disclosure does not limit the area of the proximity range. For example, in another exemplary embodiment, the proximity range may also include coding units that are currently to be encoded and/or undecoded areas in the picture.

13A and FIG. 13B are schematic diagrams of pixel group operation according to a second exemplary embodiment of the present disclosure.

Referring to FIG. 13A, in the exemplary embodiment, two pixels are selected as the first index pixel and the second index pixel in the plurality of third pixels in the proximity range 1000 of the first encoding unit 200. The color selection module 114 groups the pixels into a plurality of clusters according to the pixel values of the plurality of third pixels in the proximity range 1000. For example, assuming that the size of the first coding unit 200 is 4×4, there will be 9 third pixels in the adjacent range 1000. The color selection module 114 groups the pixels of the same color into the same cluster according to the pixel values of the pixels. For example, the two pixels belonging to the cluster 1102 have the same pixel value and the colors of the two pixels are C1, and the five pixels belonging to the cluster 1104 have the same pixel value and the colors of the five pixels are C2, and the pixels belonging to the cluster 1106 and the cluster 1108 do not have other pixels having the same pixel value, and the pixels belonging to the cluster 1106 and the pixels of the cluster 1108 are respectively C4 and C5. Then, the color selection module 114 selects a first cluster and a second cluster according to the number of pixels corresponding to each cluster. Here, by The number of pixels in the cluster 1104 and the number of pixels in the cluster 1102 are both greater than the number of pixels in the other clusters in the cluster. Therefore, the color selection module 114 selects the cluster 1104 as the first cluster, and selects the cluster 1102. As the second cluster and one pixel in the first cluster as the first index pixel, one pixel in the second cluster is used as the second index pixel. It is to be noted that the disclosure does not limit the method of pixel grouping. For example, in another exemplary embodiment, the color selection module 114 groups pixels having similar pixel values into the same cluster.

Referring to FIG. 13B, in the exemplary embodiment, two pixels are selected as the first index pixel and the second index pixel in the plurality of third pixels in the neighborhood 1000 of the first encoding unit 200. The color selection module 114 is based on the pixel values of the plurality of third pixels in the adjacent range 1000, and the difference between the pixel values of any two pixels is less than a preset pixel difference. Within the same cluster, groups of similar colors can be grouped into the same cluster. For example, the difference between the pixel values of any two of the six pixels belonging to the cluster 1114 may be smaller than the above-mentioned predefined difference and the two pixels have similar colors C2, belonging to the cluster 1116. The difference between the pixel values of the pixels is also smaller than the above-mentioned predefined difference and the two pixels have similar colors C4, while the pixels belonging to the cluster 1112 do not have other pixels similar to their pixel values. And the color of one pixel belonging to the cluster 1112 is C1. Next, the color selection module 114 selects the first cluster and the second cluster according to the number of pixels corresponding to each cluster. Here, since the number of pixels of the cluster 1114 and the number of pixels of the cluster 1116 are both larger than the number of pixels of the other clusters in the cluster, the color selection module 114 selects the cluster 1114 as the first cluster, and Selection cluster 1116 is used as the second cluster. And one pixel in the first cluster is used as the first index pixel, and one pixel in the second cluster is used as the second index pixel.

Next, the index setting module 116 sequentially sets the index value corresponding to the first index pixel to 0 and the index value corresponding to the second index pixel to 1. And in the operation of the encoding module 112 to transmit the encoded value to the decoder 120, the encoding module 112 also transmits the identification value corresponding to each pixel pair or the color of the first index pixel and the color of the second index pixel. To the decoder to the decoder 120. For example, in the example of FIG. 13A, the first index pixel belongs to the cluster 1104, and the second index pixel belongs to the cluster 1102. Therefore, the color of the first index pixel and the color of the second index pixel are C2 and C1, respectively. In the example of FIG. 11B, the first index pixel belongs to the cluster 1114 and the second index pixel belongs to the cluster 1116. Therefore, the colors of the first index pixel and the second index pixel are C2 and C5, respectively.

After that, the index map creation module 118 uses the two-color mode to index each pixel in the first coding unit 200 to generate an index map. The encoding module 112 generates the corresponding first coding unit 200 according to the index map. The operation of encoding the value, and the operation of the encoding module 112 to transmit the encoded value 600 to the decoder 120 are the same as those described in the first exemplary embodiment, and will not be repeated here.

In addition, after the coded value receiving module 122 of the decoder 120 receives the coded value corresponding to the first coding unit 200, the decoding module 124 reconstructs the operation of the index map corresponding to the first coding unit 200 according to the coded value, which is also the same. The operations of FIGS. 10A to 10G in the first exemplary embodiment are not repeated here. Accordingly, the decoding module 124 can be based on the obtained color of the first index pixel, the color of the second index pixel, and A plurality of index values of the map are indexed to reconstruct a plurality of pixels of the first coding unit 200.

[Third exemplary embodiment]

The encoding method and decoding method of the third exemplary embodiment and the system thereof are essentially the same as the encoding method and decoding method of the first and second exemplary embodiments and the system thereof, and the difference is that it is used in the third exemplary embodiment. The range from which two pixels are selected may be extended to other adjacent coding units and the third exemplary embodiment also selects two pixels as the first index pixel and the second index pixel in a statistical and quantitative manner. The differences between the third exemplary embodiment and the first and second exemplary embodiments will be described below using the system and component numbers of the first exemplary embodiment.

FIG. 14 is a schematic diagram of an image encoding operation according to a third exemplary embodiment of the present disclosure.

Referring to FIG. 14 , similar to the first exemplary embodiment, the encoding module 112 selects two pixels from the plurality of pixels in the vicinity of the first encoding unit 200 as the first index pixel and the second index drawing. Prime. However, the disclosure is not limited thereto. For example, in another exemplary embodiment, the encoding module 112 may select two pixels from all the pixels in the picture as the first index pixel and the second index pixel. It is assumed here that the size of the first coding unit 200 in a picture received by the coding module 112 is L×L, and L is a positive integer. In particular, in the present exemplary embodiment, the neighboring range includes a plurality of pixels adjacent to the first encoding unit 200 in the at least one second encoding unit 1220 adjacent to the first encoding unit 200 (hereinafter referred to as a third pixel) ). Here, the range of the third pixels belongs to the proximity range 1000. In addition, the proximity range further includes the proximity of the adjacent range 1000 to the proximity of the second coding unit 1202 in the at least one second coding unit 1220. The range 1200-1 and the adjacent range 1000 extend to the proximity range 1200-2 of the second coding unit 1204 in the at least one second coding unit 1220. That is, the encoding module 112 selects two pixels from the plurality of pixels in the adjacent range 1000, the adjacent range 1200-1, and the adjacent range 1200-2 as the first index pixel and the second index pixel.

15A and FIG. 15B are schematic diagrams of pixel group operation according to a third exemplary embodiment of the present disclosure.

Referring to FIG. 15A, in the present exemplary embodiment, two pixels are selected as the first index pixel in the pixels in the adjacent range 1000, the adjacent range 1200-1, and the adjacent range 1200-2 of the first encoding unit 200. In the operation of the second index pixel, the color selection module 114 groups the pixels into a plurality of pixels according to the pixel values of the pixels in the proximity range 1000, the proximity range 1200-1, and the proximity range 1200-2. Cluster. For example, assuming that the size of the first coding unit 200 is 4×4, there will be 17 pixels in the proximity range 1000. The color selection module 114 groups the pixels of the same color into the same cluster according to the pixel values of the pixels. For example, the four pixels belonging to the cluster 1302 have the same pixel value and the colors of the four pixels are C1, and the seven pixels belonging to the cluster 1304 have the same pixel value and the colors of the seven pixels are C2, the pixels belonging to the cluster 1306 do not have other pixels whose pixel values are the same and the color of the one pixel is C4, and the three pixels belonging to the cluster 1308 have the same pixel value and the three pixels The color is C5, and the two pixels belonging to cluster 1310 have the same pixel value and the color of the two pixels is C6. Next, the color selection module 114 selects the first cluster and the second cluster according to the number of pixels corresponding to each cluster. Here, the number of pixels of the cluster 1302 is larger than the number of pixels of the cluster 1304. The number of pixels of other clusters in the cluster, therefore, color selection module 114 will select cluster 1302 as the first cluster and select cluster 1304 as the second cluster. And one pixel in the first cluster is used as the first index pixel, and one pixel in the second cluster is used as the second index pixel. It should be noted that the disclosure does not limit the method of pixel grouping. For example, in another exemplary embodiment, the color selection module 114 groups pixels having similar pixel values into the same cluster.

Referring to FIG. 15B, in the exemplary embodiment, two pixels are selected as the first index pixel in the pixels in the adjacent range 1000, the adjacent range 1200-1, and the adjacent range 1200-2 of the first encoding unit 200. In the operation of the second index pixel, the color selection module 114 is based on the pixel values of the pixels in the adjacent range 1000, and the difference between the pixel values of any two pixels is less than a predefined difference. The pixels are grouped into the same cluster, so that pixels of similar colors can be grouped into the same cluster. For example, the difference between the pixel values of any two of the four pixels belonging to the cluster 1312 may be smaller than the above-mentioned predefined difference and the two pixels have similar colors C1, belonging to the cluster 1314. The difference between the pixel values of any two pixels in the pixels is smaller than the above-mentioned predefined difference and the two pixels have similar colors C2, and any two of the five pixels belonging to the cluster 1316 The difference between the pixel values of the pixels is also smaller than the above-mentioned predefined difference and the two pixels have similar colors C5. Next, the color selection module 114 selects the first cluster and the second cluster according to the number of pixels corresponding to each cluster. Here, since the number of pixels of the cluster 1314 and the number of pixels of the cluster 1316 are greater than the number of pixels of the other clusters in the cluster, the color selection module 114 selects the cluster 1314 as the first cluster, and Selection cluster 1316 As the second cluster and one pixel in the first cluster as the first index pixel, one pixel in the second cluster is used as the second index pixel.

Next, the index setting module 116 sequentially sets the index value corresponding to the first index pixel to 0 and the index value corresponding to the second index pixel to 1. And in the operation of the encoding module 112 to transmit the encoded value to the decoder 120, the encoding module 112 also transmits the identification value corresponding to each pixel pair or the color of the first index pixel and the color of the second index pixel. To the decoder to the decoder 120. For example, in the example of FIG. 15A, the first index pixel belongs to the cluster 1304, and the second index pixel belongs to the cluster 1302. Therefore, the colors of the first index pixel and the second index pixel are C2 and C1, respectively. In FIG. 13B, the first index pixel belongs to the cluster 1314, and the second index pixel belongs to the cluster 1316. Therefore, the colors of the first index pixel and the second index pixel are C2 and C5, respectively.

After that, the index map creation module 118 uses the two-color mode to index each pixel in the first coding unit 200 to generate an index map. The encoding module 112 generates the corresponding first coding unit 200 according to the index map. The operation of encoding the value, and the operation of the encoding module 112 to transmit the encoded value 600 to the decoder 120 are the same as those of the first exemplary embodiment, and will not be repeated here.

In addition, after the coded value receiving module 122 of the decoder 120 receives the coded value corresponding to the first coding unit 200, the decoding module 124 reconstructs the operation of the index map corresponding to the first coding unit 200 according to the coded value, which is also the same. The operations of FIGS. 10A to 10G in the first exemplary embodiment are not repeated here. Accordingly, the decoding module 124 can be based on the obtained color of the first index pixel, the color of the second index pixel, and A plurality of index values of the map are indexed to reconstruct a plurality of pixels of the first coding unit 200.

In summary, the encoding method and the decoding method and the codec system, the encoder and the decoder using the method of the present disclosure record only the first picture among the pixels of the corresponding coding unit by using the coding and decoding system, the encoder and the decoder using the method. The index value of the prime is in the encoded value, thereby effectively reducing the amount of transmission during the encoding operation, thereby effectively improving the performance of the encoding and decoding.

Steps of the S701, S703, S705, S707‧‧ ‧ encoding methods

Claims (42)

An encoding method comprising: receiving a first coding unit of a picture, wherein the first coding unit has a plurality of pixels in the form of an L×L matrix, wherein L is a positive integer; and a plurality of pictures in the picture Selecting two pixels as a first index pixel and a second index pixel, wherein the color of the first index pixel is different from the color of the second index pixel; and the first coding unit Each pixel is indexed to generate an index map, wherein the color of each pixel of the first coding unit in the index map is an index value corresponding to the first index pixel or corresponds to the second index The index value of the pixel is presented, wherein only the index value of the first pixel of the pixels corresponding to the first coding unit in the index map is recorded in an encoded value. The encoding method of claim 1, wherein the pixels in the picture comprise a plurality of third cells adjacent to the first coding unit in the at least one second coding unit adjacent to the first coding unit. Picture. The encoding method of claim 2, wherein the third pixels are respectively two pixels adjacent to an upper edge and a left edge of the first row and the first column of the first coding unit. a pixel adjacent to an upper edge of the first column of the Lth row of the first coding unit, adjacent to a pixel of a left edge of the first row and the Lth column of the first coding unit And a pixel corresponding to an upper left corner of the first row and the first column of pixels of the first coding unit. An encoding method as described in claim 3, wherein in the picture The steps of selecting the two pixels as the first index pixel and the second index pixel include: creating a pixel pair table; generating a plurality of pixel pairs according to the third pixels, And recording, in the pixel pair table, a recognition value corresponding to each of the pair of pixels and a color of each set of pixel pairs corresponding to the identification value; and selecting one of the pixel pairs according to the pixel pair table The two pixels of the one of the pixel pairs are set to the first index pixel and the second index pixel. The encoding method of claim 2, wherein the step of selecting the two pixels as the first index pixel and the second index pixel in the pixels of the picture comprises: according to the The pixel values of the pixels group the pixels into a plurality of clusters, wherein the pixels in the same cluster have the same pixel values; and the number of pixels corresponding to each of the clusters is selected according to the number of pixels corresponding to each of the clusters a first cluster and a second cluster, wherein the first index pixel belongs to the first cluster, the second index pixel belongs to the second cluster, and the number of pixels of the first cluster and the second cluster The number of pixels is greater than the number of pixels in other clusters in the cluster. The encoding method of claim 2, wherein the step of selecting the two pixels as the first index pixel and the second index pixel in the pixels of the picture comprises: according to the The pixel values of the pixels group the pixels into a plurality of clusters, where The difference between the pixel values of any two pixels in the same cluster in the cluster is less than a predefined difference; and selecting a first cluster and a second according to the number of pixels corresponding to each of the clusters a cluster, wherein the first index pixel belongs to the first cluster, the second index pixel belongs to the second cluster, and the number of pixels of the first cluster and the number of pixels of the second cluster are greater than the cluster The number of pixels in other clusters in these clusters. The encoding method of claim 4, further comprising: transmitting the encoded value and the identification value to a decoding end, wherein the encoded value comprises a first one of pixels of the first coding unit The index value of the prime, at least one copy mode, and a value of at least one run character. The encoding method of claim 1, further comprising: directly transmitting the code value, the color of the first index pixel and the color of the second index pixel to a decoding end, wherein the code value includes the An index value of the first pixel among the pixels of the first coding unit, at least one copy mode, and a value of at least one run character. A decoding method includes: receiving an encoded value corresponding to a first coding unit, wherein the first coding unit has a plurality of pixels in an L×L matrix, where L is a positive integer; according to the encoded value An index value corresponding to the first coding unit is reconstructed by an index value, at least one copy mode, and a value of at least one run character, wherein the received index value in the encoded value includes only the first coding unit in the index map The An index value of the first pixel of the pixel; a color of a first index pixel and a color of a second index pixel; and a color according to the first index pixel, the second index pixel The color and the plurality of index values of the index map reconstruct the pixels of the first coding unit, wherein a color of the first index pixel is different from a color of the second index pixel. The decoding method of claim 9, wherein an index value of each pixel corresponding to the first coding unit in the index map is arranged in the L×L matrix form, and has been The number of scanned indexes is c, where c is a positive integer greater than 0 and less than or equal to (L×L), and the index of the first pixel is the first index scanned in the index map. The step of reconstructing the index map corresponding to the first coding unit according to the index value in the code value and the value of the running character includes: if the copy mode of the c-th index is a left-left copy run mode, then When the pixel corresponding to the first index scanned in the index map is decoded, the index map is reconstructed according to the first index scanned in the index map and the value of the running character, and the index map has been scanned in the index map. When the number of indexes is less than or equal to L, the scanned c-th index is converted into a coordinate (x, y), and the scanned c-1 index is converted into a coordinate (m, n), wherein The value of the index of the coordinates (m, n) should be P; and when the decoding corresponds to the index When the pixel of the c-th index is scanned in the map, the index map is reconstructed according to the scanned c-1 index and the value of the running character in the index map, where the scanned map is in the index map The value of c indexes is (P+1) Divide by the remainder obtained by 2. The decoding method of claim 10, wherein the step of reconstructing the index map corresponding to the first coding unit according to the index value, the copy mode, and the value of the running character in the encoded value further comprises: Decoding the pixel corresponding to the c-th index scanned in the index map, determining whether the copy mode corresponding to the c-1 index is using an upward copy run mode or the left copy run mode to decode the corresponding index The pixel of the c-1th index scanned in the map, wherein the number of indexes that have been scanned in the index map is greater than L; the c-th index scanned in the index map is converted into coordinates (x , y), convert the scanned c-1 index into coordinates (m, n), and convert the scanned cL index corresponding to the index map into coordinates (p, q), which corresponds to The value of the index of the coordinates (p, q) is Q and the value of the index corresponding to the coordinate (m, n) is R; when it is judged to use the upward copy run mode to decode the c-1th scan corresponding to the index map When the pixel of the index is indexed, according to the corresponding cL that has been scanned in the index map And indexing the index map with the value of the running character, wherein the value of the c-th index scanned in the index map is (Q+1) divided by 2, and when it is determined to use the left-copy mode Decoding the pixel corresponding to the c-1th index scanned in the index map, reconstructing the index map according to the value of the c-1 index scanned in the index map and the running character, wherein the index map The value of the c-th index scanned in (R+1) divided by 2 is the remainder. The decoding method of claim 9, wherein an index value of each pixel corresponding to the first coding unit in the index map is in the L×L matrix shape. Arranged, and the number of indexes that have been scanned in the index map is c, where c is a positive integer greater than 0 and less than or equal to (L x L), wherein the index value according to the encoded value The copying mode and the value of the running character reconstructing the index map corresponding to the first coding unit further comprises: when decoding the pixel corresponding to the c-th index scanned in the index map, determining that the corresponding c index The copy mode is to use an up copy run mode or a left copy run mode to decode a pixel corresponding to the cth index scanned in the index map, wherein the number of indexes that have been scanned in the index map is greater than L; when it is judged that the pixel corresponding to the c-th index scanned in the index map is decoded by using the upward copy running mode, the c-th index scanned in the index map is converted into a coordinate (x, y), The cL index that has been scanned in the index map is converted into a coordinate (p, q), and the index map is reconstructed based on the scanned cL index and the value of the running character in the index map. The decoding method of claim 9, wherein the step of obtaining the color of the first index pixel and the color of the second index pixel comprises: receiving a corresponding first index pixel and the second index An identification value of the prime; and identifying, according to the identification value, a color of the first index pixel from a pixel pair table and a color of the second index pixel. The decoding method of claim 9, wherein the step of obtaining the color of the first index pixel and the color of the second index pixel comprises: receiving a color of the first index pixel and the second index The color of the pixels. An encoder, comprising: an encoding module, receiving a first coding unit of a picture, wherein the first coding unit has a plurality of pixels in an L×L matrix, wherein L is a positive integer; a color selection module, wherein two pixels are selected as a first index pixel and a second index pixel in the plurality of pixels in the picture, wherein the color of the first index pixel is different from the second a color of the index pixel; and an index map building module, indexing each pixel in the first coding unit to generate an index map, wherein each picture of the first coding unit in the index map The color of the prime is represented by an index value corresponding to the first index pixel or an index value corresponding to the second index pixel, wherein only the first of the pixels of the first coding unit is corresponding to the index map The index values of the pixels are recorded in an encoded value. The encoder of claim 15, wherein the pixels in the picture comprise a plurality of thirds adjacent to the first coding unit in the at least one second coding unit adjacent to the first coding unit Picture. The encoder of claim 16, wherein the third pixels are respectively two pixels adjacent to an upper edge and a left edge of the first row and the first column of the first coding unit. a pixel adjacent to an upper edge of the first row and the Lth column of pixels of the first coding unit, adjacent to a pixel of a left edge of the first column of pixels of the Lth row of the first coding unit And a pixel corresponding to an upper left corner of the first row and the first column of pixels of the first coding unit. For example, the encoder described in claim 17 includes a pixel pair. a table establishing module, configured to establish a pixel pair table, wherein the pixel pair table creating module generates a plurality of pixel pairs according to the third pixels, and corresponding to each of the pixel pairs The color of each set of pixels corresponding to the value and the corresponding value is recorded in the pixel pair table, wherein the color selection module selects one of the pixel pairs according to the pixel pair table, wherein the one of the pixel pairs Two pixels are set as the first index pixel and the second index pixel. The encoder of claim 16, wherein the color selection module further groups the pixels into a plurality of clusters according to pixel values of the pixels, wherein the same clusters are among the pixels. The pixel values of the pixels in the same are the same, wherein the color selection module further selects a first cluster and a second cluster according to the number of pixels corresponding to each of the clusters, wherein the first index pixel belongs to the first a cluster, the second index pixel belongs to the second cluster, and the number of pixels of the first cluster and the number of pixels of the second cluster are greater than the number of pixels of other clusters in the cluster . The encoder of claim 16, wherein the color selection module further groups the pixels into a plurality of clusters according to pixel values of the pixels, wherein the clusters are in the same cluster. The difference between the pixel values of any two pixels is less than a predefined difference, wherein the color selection module selects a first cluster and a second cluster according to the number of pixels corresponding to each of the clusters. The first index pixel belongs to the first cluster, and the second index pixel belongs to The second cluster, and the number of pixels of the first cluster and the number of pixels of the second cluster are both greater than the number of pixels of other clusters among the clusters. The encoder of claim 18, wherein the encoding module is further configured to transmit the encoded value and the identification value to a decoder, wherein the encoded value comprises a pixel of the first coding unit. The index value of the first pixel, at least one copy mode, and a value of at least one run character. The encoder of claim 15, wherein the encoding module directly transmits the encoded value, the color of the first index pixel and the color of the second index pixel to a decoder, wherein the encoding value The index value of the first pixel among the pixels of the first coding unit, at least one copy mode, and a value of at least one run character. A decoder comprising: an encoded value receiving module, receiving an encoded value corresponding to a first coding unit, wherein the first coding unit has a plurality of pixels in the form of an L×L matrix, wherein L is a positive integer And a decoding module, reconstructing an index map corresponding to the first coding unit according to an index value, at least one copy mode, and at least one running character value in the encoded value, wherein the received index in the encoded value The value includes only the index value of the first pixel of the pixels of the first coding unit in the index map, wherein the decoding module obtains a color of a first index pixel and a second index pixel Color, wherein the decoding module draws the second index according to the color of the first index pixel The color of the prime and the plurality of index values of the index map reconstruct the pixels of the first coding unit, wherein the color of the first index pixel is different from the color of the second index pixel. The decoder of claim 23, wherein an index value of each pixel corresponding to the first coding unit in the index map is arranged in the L×L matrix form, and has been The number of scanned indexes is c, where c is a positive integer greater than 0 and less than or equal to (L×L), and the index of the first pixel is the first index scanned in the index map. Wherein, if the copy mode of the c-th index is a left-to-left copy mode, when the decoding module decodes the pixel corresponding to the first index scanned in the index map, according to the scan in the index map Resetting the index map by the first index and the value of the running character, wherein the decoding module scans the index c in the index map when the number of indexes that have been scanned in the index map is less than or equal to L Indexes are converted to coordinates (x, y), and the scanned c-1th index is converted into coordinates (m, n), wherein the value of the index corresponding to the coordinates (m, n) is P, where When the decoding module decodes the pixel corresponding to the c-th index scanned in the index map, according to the cable Retrieving the index map by the scanned c-1 index and the value of the running character in the map, wherein the value of the scanned c index in the index map is obtained by dividing (P+1) by 2 remainder. The decoder of claim 24, wherein when the decoding module decodes a pixel corresponding to the c-th index scanned in the index map, the copy corresponding to the c-1 index is further determined. The mode is to use an upward copy run mode or the left copy run mode to decode the c-1 index scanned in the corresponding index map. a pixel, wherein the number of indexes that have been scanned in the index map is greater than L, wherein the decoding module converts the c-th index scanned in the index map into coordinates (x, y), The scanned c-1 index is converted into a coordinate (m, n), and the scanned cL index in the index map is converted into a coordinate (p, q), wherein the index corresponding to the coordinate (p, q) The value of Q and the index of the corresponding coordinate (m, n) are R, wherein when the decoding module determines to use the upward copy run mode to decode the picture corresponding to the c-1 index scanned in the index map When the prime, the index map is reconstructed according to the cL index and the running character value in the index map, wherein the value of the c index scanned in the index map is (Q+1) divided by 2 a remainder obtained, wherein when the decoding module uses the left copy mode to decode the pixel corresponding to the c-1th index scanned in the index map, according to the corresponding scanned c in the index map - indexing the index map with the value of the index and the run character, wherein the index c is scanned in the index map The value obtained by dividing (R+1) by 2 is the remainder. The decoder of claim 23, wherein an index value of each pixel corresponding to the first coding unit in the index map is arranged in the L×L matrix form, and has been The number of scanned indexes is c, where c is a positive integer greater than 0 and less than or equal to (L×L), wherein when the decoding module decodes the pixels corresponding to the c-th index scanned in the index map , determining that the copy mode corresponding to the c-th index is to use an upward copy run mode or a left copy run mode to decode the scan corresponding to the index map a pixel of the c-th index, wherein the number of indexes that have been scanned in the index map is greater than L, wherein when the decoding module determines to use the upward copy run mode to decode the corresponding c-scan in the index map When the elements of the index are converted, the c-th index scanned in the index map is converted into a coordinate (x, y), and the c-th index scanned in the index map is converted into a coordinate (p, q). And reconstructing the index map based on the scanned cL index and the value of the running character in the index map. The decoder of claim 23, wherein the code value receiving module further receives an identification value corresponding to the first index pixel and the second index pixel, wherein the decoding module is based on the identification value. The color of the first index pixel and the color of the second index pixel are identified from a pixel pair table. The decoder of claim 23, wherein the code value receiving module further receives the color of the first index pixel and the color of the second index pixel. A codec system comprising: an encoder receiving a first coding unit of a picture, wherein the first coding unit has a plurality of pixels in the form of an L×L matrix, wherein L is a positive integer; and a decoding The encoder selects two pixels in the plurality of pixels in the picture as a first index pixel and a second index pixel, wherein the color of the first index pixel is different from the second The color of the index pixel, wherein the encoder indexes the number of each pixel in the first coding unit An index map is generated, wherein a color of each pixel of the first coding unit in the index map is presented by an index value corresponding to the first index pixel or an index value corresponding to the second index pixel. The index value of the first pixel of the pixels corresponding to the first coding unit in the index map is recorded in the code value. The codec system of claim 29, wherein the decoder receives the encoded value corresponding to the first coding unit, wherein the decoder is based on an index value, at least one copy mode, and at least The value of a running character reconstructs the index map corresponding to the first coding unit, and the received index value in the encoded value includes only the first picture of the pixels of the first coding unit in the index map. An index value of the element, wherein the decoder obtains a color of the first index pixel and a color of the second index pixel, wherein the decoder is configured according to a color of the first index pixel and a color of the second index pixel Reconstructing the pixels of the first coding unit with a plurality of index values of the index map. The codec system of claim 29, wherein the pixels in the picture comprise a plurality of pixels adjacent to the first coding unit in the at least one second coding unit adjacent to the first coding unit Three pixels. The codec system of claim 31, wherein the third pixels are respectively two paintings of an upper edge and a left edge of the first row and the first column of the first row of the first coding unit. Prime, adjacent to the first row of the first coding unit L a pixel of the upper edge of the column of pixels, a pixel adjacent to the left edge of the first column of pixels of the Lth row of the first coding unit, and the first row corresponding to the first coding unit A pixel in the upper left corner of a pixel. The codec system of claim 32, wherein the encoder further establishes a pixel pair table, wherein the encoder generates a plurality of pixel pairs according to the third pixels, and corresponds to each of the pixels. An identification value of the pair of pixels and a color of each set of pixels corresponding to the recognized value are recorded in the pixel pair table, wherein the encoder selects one of the pixel pairs according to the pixel pair table, wherein the pixel pair Two pixels of a pixel pair are set as the first index pixel and the second index pixel. The codec system of claim 31, wherein the encoder groups the pixels into a plurality of clusters according to pixel values of the pixels, wherein the pixels are in the same cluster The pixel values of the pixels are the same, wherein the encoder selects a first cluster and a second cluster according to the number of pixels corresponding to each of the clusters, wherein the first index pixel belongs to the first cluster, the first The two index pixels belong to the second cluster, and the number of pixels of the first cluster and the number of pixels of the second cluster are greater than the number of pixels of other clusters in the cluster. The codec system of claim 31, wherein the encoder groups the pixels into a plurality of clusters according to pixel values of the pixels in the proximity range, wherein the clusters are the same The pixel values of any two pixels in a cluster The difference is less than a predefined difference, wherein the encoder selects a first cluster and a second cluster according to the number of pixels corresponding to each of the clusters, wherein the first index pixel belongs to the first cluster, and the first index pixel belongs to the first cluster, The second index pixel belongs to the second cluster, and the number of pixels of the first cluster and the number of pixels of the second cluster are greater than the number of pixels of other clusters among the clusters. The codec system of claim 33, wherein the encoder is further configured to transmit the encoded value and the identification value to the decoder, and the encoded value includes a pixel of the first coding unit. The index value of the first pixel, at least one copy mode, and a value of at least one run character. The codec system of claim 29, wherein the encoder directly transmits the coded value, the color of the first index pixel and the color of the second index pixel to the decoder, wherein the code value The index value of the first pixel among the pixels of the first coding unit, at least one copy mode, and a value of at least one run character. The codec system of claim 30, wherein an index value of each pixel corresponding to the first coding unit in the index map is arranged in the L×L matrix, and in the index map The number of indexes to be scanned is c, where c is a positive integer greater than 0 and less than or equal to (L×L), and the index value of the first pixel is the first index scanned in the index map. Wherein, if the copy mode of the c-th index is a left-left copy run mode, when the decoder decodes the pixel corresponding to the first index scanned in the index map And reconstructing the index map according to the first index scanned in the index map and the value of the running character, wherein when the number of indexes that have been scanned in the index map is less than or equal to L, the decoder will The scanned c-th index is converted to a coordinate (x, y), and the scanned c-1 index is converted into a coordinate (m, n), wherein the value of the index corresponding to the coordinate (m, n) is P, wherein when the decoder decodes a pixel corresponding to the c-th index scanned in the index map, the index map is reconstructed according to the scanned c-1 index and the value of the running character in the index map. , wherein the value of the c-th index scanned in the index map is (P+1) divided by 2 to obtain a remainder. The codec system of claim 38, wherein when the decoder decodes a pixel corresponding to the c-th index scanned in the index map, it further determines a copy mode corresponding to the c-1th index. Is to use an upward copy run mode or the left copy run mode to decode a pixel corresponding to the c-1th index scanned in the index map, wherein the number of indexes that have been scanned in the index map is greater than L , wherein the decoder converts the c-th index scanned in the index map into coordinates (x, y), converts the scanned c-1 index into coordinates (m, n), and corresponds to The cL index scanned in the index map is converted into a coordinate (p, q), wherein the value of the index corresponding to the coordinate (p, q) is Q and the value of the index corresponding to the coordinate (m, n) is R, When the decoder determines to use the up copy run mode to decode the pixel corresponding to the c-1th index scanned in the index map, according to the scanned map in the index Refining the index map by cL indexes and values of the running characters, wherein the value of the c-th index scanned in the index map is (Q+1) divided by 2, wherein the decoder uses the Copying the running mode to the left to decode the pixel of the c-1th index scanned in the index map, reconstructing the index map according to the value of the c-1 index scanned in the index map and the value of the running character , wherein the value of the c-th index scanned in the index map is (R+1) divided by 2 to obtain the remainder. The codec system of claim 30, wherein an index value of each pixel corresponding to the first coding unit in the index map is arranged in the L×L matrix, and in the index map The number of indexes to be scanned is c, where c is a positive integer greater than 0 and less than or equal to (L x L), wherein when the decoder decodes the pixels corresponding to the c-th index scanned in the index map Determining that the copy mode corresponding to the c-th index is to use an up copy run mode or a left copy run mode to decode a pixel corresponding to the c-th index scanned in the index map, wherein the index map has The number of indexes to be scanned is greater than L, wherein when the decoder determines to use the upward copy run mode to decode the pixels corresponding to the c-th index scanned in the index map, the corresponding scan in the index map will be The c indexes are converted into coordinates (x, y), and the cL index that has been scanned in the index map is converted into coordinates (p, q), and the cL index and the run are scanned according to the index map. The value of the character reconstructs the index map . The codec system of claim 30, wherein the decoder further receives an identification value corresponding to the first index pixel and the second index pixel, The decoder identifies the color of the first index pixel and the color of the second index pixel from a pixel pair table according to the identification value. The codec system of claim 30, wherein the decoder further receives the color of the first index pixel and the color of the second index pixel.