WO2020135357A1

WO2020135357A1 - Data compression method and apparatus, and data encoding/decoding method and apparatus

Info

Publication number: WO2020135357A1
Application number: PCT/CN2019/127600
Authority: WO
Inventors: 邵庆龙; 高俊平; 蒲宇亮; 崔振峰
Original assignee: 中兴通讯股份有限公司
Priority date: 2018-12-29
Filing date: 2019-12-23
Publication date: 2020-07-02
Also published as: CN109831668B; CN109831668A

Abstract

Disclosed in the present application are a data compression method and apparatus, and a data encoding/decoding method and apparatus; in the data encoding method described in the present application, an encoding block to be processed is first classified before encoding, and lossy encoding or lossless encoding is used for different types of encoding blocks to be processed, thus reducing the occupied transmission bandwidth; moreover, a decoding end uses chromaticity information to perform necessary color compensation on decoded data of a bitstream that has undergone lossy encoding, thus ensuring the fidelity of transmitted data.

Description

Data compression method and device, data encoding/decoding method and device

Technical field

This application relates to, but not limited to, video processing technology, and in particular, to a data compression method and device, data encoding/decoding method and device.

Background technique

With the popularization of technologies such as cloud computing and virtual desktops, a large amount of remote data needs to be transmitted to users through the network for processing. Based on the existing image compression technology, the transmission of desktop content under narrow-bandwidth network conditions has not been met. Therefore, based on Video encoding technology for screen content is widely used in the field of virtual desktops.

In order to achieve high fidelity of picture quality in cloud desktop scenes, current video encoding schemes based on screen content are roughly divided into two categories, one is to adopt a color code table encoding scheme, and the other is to use a lossy compression encoding scheme. Among them, the color code table encoding scheme generally includes: classify similar colors according to the color distribution of the text block, generate the same color code table, use lossless compression for the color code table, and completely restore the text block according to the index value at the decoding end content. The color code table coding scheme is suitable for text blocks with relatively single color distribution. When the color distribution is complex and there are many types of divisions, the color code table coding scheme has low coding efficiency and usually switches to the JPEG algorithm. The lossy compression coding scheme generally includes: The video sampling format generally uses a full sampling method of 4:4:4 (also a lossless compression method), which allows the chroma of the screen content to be completely retained, so it will be consumed during the encoding process More coding bits, and in order to ensure the clarity of the font that is more sensitive to the human eye, generally use completely lossless compression on the font, but this will lead to increased transmission bandwidth and reduced coding efficiency.

Summary of the invention

The present application provides a data compression method and device, data encoding/decoding method and device, which can reduce the transmission bandwidth occupation while ensuring the fidelity of data transmission.

This application provides a data compression method, including:

According to the pixel distribution information, determine whether the coding block to be processed is an image block or a text block;

For the determined text block, obtain chromaticity information, and determine whether the text block contains colored background information according to the chromaticity information;

Lossy compression is performed on the determined image blocks, lossy compression is performed on text blocks that do not contain color background information, and lossless compression is performed on text blocks that contain color background information.

This application also provides a data encoding method, including:

Lossy compression of the determined image blocks, lossy compression of text blocks that do not contain color background information, and lossless compression of text blocks that contain color background information;

Perform lossless encoding on the information after lossless compression, lossy encoding on the information after lossy compression, and encode chrominance information to complete the encoding of the encoding block to be processed.

The present application also provides a computer-readable storage medium that stores computer-executable instructions for performing the data compression method described in any one of the above, and/or any of the above Data encoding method.

The present application also provides a data compression apparatus, including a processor and a memory; wherein the memory stores a computer program that can run on the processor: for performing the steps of any one of the data compression methods described above.

The present application further provides a data encoding device, including a processor and a memory; wherein, the memory stores a computer program executable on the processor: for performing the steps of any one of the data encoding methods described above.

This application further provides a data decoding method, including:

Obtain the data packet to be decoded, and determine that the data packet to be decoded includes a lossless data packet or a lossy data packet;

After decoding the lossless data packet and filling it in the decoded frame, it is determined that the lossy data packet is an image block or a text block;

Decode the image block and fill it in the decoded frame; decode the text block and compensate the decoded text block according to the chroma information in the packet to be decoded and fill it in the decoded frame.

The present application also provides a computer-readable storage medium that stores computer-executable instructions, and the computer-executable instructions are used to perform any one of the data decoding methods described above.

The present application further provides a data decoding device, including a processor and a memory; wherein the memory stores a computer program executable on the processor: for performing the steps of any one of the data decoding methods described above.

This application classifies the coded blocks to be processed before coding, and adopts lossy coding or lossless coding for different types of coding blocks to be processed, which satisfies the reduction of transmission bandwidth occupation; moreover, the decoding end uses chrominance information to encode the lossy The decoded data after the bitstream is subjected to necessary color compensation to ensure the fidelity of the data after transmission.

Other features and advantages of the present invention will be explained in the subsequent description, and partly become obvious from the description, or be understood by implementing the present invention. The objects and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the description, claims and drawings.

BRIEF DESCRIPTION

The drawings are used to provide a further understanding of the technical solutions of the present application, and form a part of the specification. They are used to explain the technical solutions of the present application together with the embodiments of the present application, and do not constitute limitations on the technical solutions of the present application.

Figure 1 is a flow chart of the data compression method of this application;

2 is a schematic diagram of the composition structure of the data compression device of this application;

3 is a schematic diagram of the composition of the data encoding device of the present application;

4 is a flowchart of a data decoding method of this application;

FIG. 5 is a schematic diagram of the composition structure of the data decoding device of the present application.

detailed description

In order to make the purpose, technical solutions and advantages of the present application clearer, the embodiments of the present application will be described in detail below in conjunction with the accompanying drawings. It should be noted that the embodiments in the present application and the features in the embodiments can be arbitrarily combined with each other without conflict.

In the related art, the YUV4:2:2 sub-sampling method is a lossy compression method. While ensuring the integrity of the luminance component Y, each group of components in the horizontal direction, that is, the chroma component cb and the chroma component cr are shared A set of luminance component Y values are used for encoding and decoding. Using this sampling method will reduce the transmission of chrominance component Y to achieve the purpose of reducing bandwidth consumption. However, due to the large number of thin lines such as fonts and borders in the screen content video, some Even a monochrome line with a pixel of 1 will cause a decrease in the fidelity of the displayed content after the above sampling. The inventor of the present application has found through analysis that if the content of the screen is classified before encoding, then different encoding strategies are adopted for different types of screen content to meet the requirement of reducing the transmission bandwidth occupation; at the same time, the lossy compression Partially compensate to ensure the fidelity of the displayed content.

Figure 1 is a flowchart of the data compression method of this application, as shown in Figure 1, including:

Step 100: Determine the coding block to be processed as an image block or a text block according to the pixel distribution information.

In an exemplary example, this step may include:

According to the gradient characteristics and color distribution information of the pixel distribution inside the coding block to be processed, the image block and the text block are distinguished from the coding block to be processed.

First calculate the literary and artistic characteristics of the area, and use the strong contrast between the strong text boundary and the non-text area to distinguish the image scene and the text scene.

In an exemplary example, before this step, the method may further include:

For the changing area in the original screen data, the pixels of the original screen data are color space converted, that is, the pixels of the original screen data are converted from RGB color space to YUV color space such as YUV4:4:4 color space;

The original screen data is divided into blocks according to the coding unit size to obtain the coding block to be processed.

Among them, YUV refers to the pixel format that the luminance parameter and the chromaticity parameter are separately expressed, Y represents the brightness (Luminance, Luma), U and V represent the chromaticity (Chrominance, Chroma).

YUV4:4:4 sampling means that the sampling ratio of the three components of the luminance component Y, the chroma component U, and the chroma component V is the same. Therefore, in the generated image, the information of the three components of each pixel is complete. 8-bit bit is one byte.

Step 101: Obtain chromaticity information, and determine whether the text block contains colored background information according to the chromaticity information.

In an exemplary example, this step may include:

Count the color types of a single coding unit such as a 16X16 coding unit to obtain chromaticity information;

When the statistical color category exceeds (eg, greater than or equal to) the preset first threshold, then the text block is determined to be a color background area class, that is, the text block contains color background information; when the statistical color category is less than ( For example, less than) the preset first threshold, then it is determined that the text block is a non-color background area type, that is, the text block does not contain color background information.

Here, the preset first threshold may be configured according to actual application scenarios and experience.

Optionally, in an exemplary example, when the statistical color type is lower than a preset first threshold, that is, the text block does not contain color background information, it may further include:

If most of the pixel chromaticity distribution of the text block is within the preset error range of the preset value, such as around 128, then determine that the text block is a non-color background and color text area class, that is, the text block does not contain color background information but the text Is colored text;

If the pixel chromaticity values of the text block are all distributed within the preset error range of the preset value, such as around 128, it means that the text block has no color information, and the text block is determined to be a non-color background and a non-color text area class The text block does not contain colored background information and the text is non-color text.

In an exemplary example, obtaining chroma information in this step includes:

For text blocks containing colored background information, the color types of the text blocks are counted; when the luminance component Y is the same, but the chrominance component difference is greater than the preset first threshold, the luminance component Y is used for offset processing to convert the luminance The value of component Y is offset to distinguish different colors.

For a text block that does not contain color background information, if the text block does not contain color background information but the text is color text, the color type of the text block is counted; when the brightness component Y is the same, but the chrominance component difference is greater than the preset At the first threshold, the luminance component Y is used for offset processing, and the value of the luminance component Y is offset to distinguish different colors. If the text block does not contain colored background information and the text is non-color text, the color type of the text block is not counted.

Here, the statistical chrominance information can be used to perform necessary color compensation on the decoded data of the lossy-encoded code stream to ensure the fidelity of the transmitted data.

Step 102: Perform lossy compression on the image block, lossy compression on the text block that does not contain color background information, and lossless compression on the text block that contains color background information.

In an illustrative example, the image blocks are sub-sampled to achieve lossy compression.

In one illustrative example, text blocks that do not contain color background information are sub-sampled to achieve lossy compression.

In an exemplary example, a text block containing colored background information is fully sampled to achieve lossless compression.

In an exemplary example, sub-sampling may include, but is not limited to, such as YUV4:2:2 sampling, YUV4:2:0, etc. Among them, YUV 4:2:2 sampling means that the chrominance component U and chrominance component V are half of the luminance component Y sampling, and the luminance component Y and chrominance component U and chrominance component V are sampled at a ratio of 2:1. For example, if there are 10 pixels in the horizontal direction, then 10 luminance components Y are sampled, and only 5 chroma components U and chroma components V are sampled.

In an exemplary example, full sampling may include, but is not limited to, YUV 4:4:4 sampling and the like.

In an exemplary example, for a text block containing color background information, the luma component Y is fully sampled to achieve lossless compression, and the chroma component U and chroma component V are sub-sampled to achieve lossy compression.

Optionally, in an exemplary example, if a text block that does not contain colored background information is further divided into: a text block that does not contain colored background information but the text is colored text, and a text block that does not contain colored background information and the text is achromatic Text blocks of text; then, in this step, sub-sampling text blocks that do not contain colored background information to achieve lossy compression, including:

Subsampling text blocks that do not contain colored background information but the text is colored text to achieve lossy compression;

Sub-sampling text blocks that do not contain color background information and the text is non-color text to achieve lossy compression.

In the data compression method of the present application, the encoding blocks to be processed are classified before encoding, and different types of encoding blocks to be processed are sampled using different compression methods, which satisfies the reduction of transmission bandwidth occupation.

The present application also provides a data encoding method. Based on the data compression method shown in FIG. 1, the method further includes:

Step 103: Perform lossless encoding on the lossless compressed information, perform lossy encoding on the lossy compressed information, and encode the chroma information to complete the encoding of the encoding block to be processed.

In an exemplary example, a lossless encoder can be called to losslessly encode the information after lossless compression, a lossy encoder can be called to lossy encode the information after lossy compression, and a lossless encoder can be called to perform chroma information To encode.

In an exemplary example, the lossless encoder may include, but is not limited to: ZLIB, GLZ and other encoders.

In an exemplary example, the lossy encoder may include, but is not limited to: X264, X265 and other encoders.

The data encoding method of the present application classifies the encoding blocks to be processed before encoding, and adopts lossy encoding or lossless encoding for different types of encoding blocks to be processed, which satisfies the reduction of transmission bandwidth occupation; moreover, the decoding end uses chrominance information Perform necessary color compensation on the decoded data of the lossy encoded code stream to ensure the fidelity of the transmitted data.

In this way, the lossy encoded data packet, the lossless encoded data packet and the chroma encoded data packet are obtained through the data encoding method of the present application, and the data packet to be decoded is obtained after integrating the obtained data packet, and the integrated code stream will be output to the receiving end to receive After decoding, the original information before encoding can be recovered. For the specific implementation of decoding, please refer to Figure 4.

It should be noted that different types of compressed blocks, different types of encoded data packets, and chroma information are set with different identifiers in this application, so that the receiving end uses different decoding strategies to distinguish.

This application is compatible and not limited to the currently widely used video transmission protocols such as H.264, H.265, etc. The identification information used to distinguish between different compression types, different encoding types, and chroma information in this application can be NAL unit extension field to record. Taking the H.264 or H.265 data frame as the delimiter to divide the network sampling layer (NAL, Network, Abstract, Layer) unit as 00.00, 00, 00, or 01 as an example, field 5 in H.264 represents instant decoding refresh (IDR, Instantaneous Decoding (Refresh) frame, field 7 represents the sequence parameter set (SPS, Sequence Parameter Set), self-calculated 8 represents the image parameter set (PPS, Picture Parameter Set). In this application, the NAL reserved fields 16-18 can be used to separately store the above identification information and other information for use in decoding at the decoding end.

An embodiment of the present invention further provides a computer-readable storage medium that stores computer-executable instructions, and the computer-executable instructions are used to perform any one of the data compression method and/or data encoding method described above.

An embodiment of the present invention further provides a data compression apparatus, including a processor and a memory; wherein, the memory stores a computer program that can run on the processor: for performing any of the steps of the above data compression method

An embodiment of the present invention further provides a data encoding device, including a processor and a memory; wherein, the memory stores a computer program that can run on the processor: for performing any of the steps of the data encoding method described above.

2 is a schematic diagram of the composition structure of the data compression device of the present application. As shown in FIG. 2, it includes at least: a first distinction module, a second distinction module, a statistics module, a lossy compression module, and a lossless compression module;

The first differentiation module is configured to determine that the coding block to be processed is an image block or a text block according to pixel distribution information;

The second distinction module is set to determine whether the text block contains colored background information according to the chromaticity of the pixels;

The statistics module is set to obtain the chroma information of the text block;

The lossy compression module is set to perform lossy compression on image blocks and lossy compression on text blocks that do not contain color background information;

The lossless compression module is set to perform lossless compression on text blocks containing colored background information.

Optionally, in an exemplary example, the data compression apparatus of the present application may further include:

The third distinction module is set to determine that the text block that does not contain color background information is a text block that does not contain color background information but the text is color text, or is a text that does not contain color background information and the text is non-color text according to the chromaticity distribution. Block; at this time,

The statistics module is specifically configured to: count the chroma information of the text block containing the color background information, and count the chroma information of the text block which does not contain the color background information but the text is color text.

In an exemplary example, the second distinction module is specifically set as:

In an exemplary example, the third distinction module is specifically set as:

If most of the pixel chromaticity distribution of the text block is within the preset error range of the preset value, such as around 128, then determine that the text block is a non-color background and color text area class, that is, the text block does not contain color background information but the text It is colored text; if the pixel chromaticity values of the text block are all distributed within the preset error range of the preset value, such as around 128, it means that the text block has no color information, and the text block is determined to be an achromatic background and achromatic text Area class, that is, the text block does not contain colored background information and the text is non-color text.

FIG. 3 is a schematic diagram of the composition structure of the data encoding device of the present application. As shown in FIG. 3, it includes at least: a first distinguishing module, a second distinguishing module, a statistics module, a lossy compression module, a lossless compression module, a lossy encoder, and a lossless Encoder; where,

Lossless compression module, set to losslessly compress text blocks containing colored background information;

Lossy encoder, set to lossy encode the information after lossy compression;

Lossless encoder, set to losslessly encode information after lossless compression; encode chroma information.

The specific implementation of the first distinguishing module, the second distinguishing module, the statistics module, the lossy compression module, and the lossless compression module in FIG. 3 are the same as those in FIG. 2, and will not be repeated here.

FIG. 4 is a flowchart of a data decoding method of the present application. As shown in FIG. 4, it includes:

Step 400: Obtain the data packet to be decoded, and determine that the data packet to be decoded includes a lossless data packet or a lossy data packet.

In an exemplary example, the data packet to be decoded includes any one or any combination of the following: lossy encoded data packet, lossless encoded data packet, and chroma encoded data packet.

In an exemplary example, the lossless coded data packet includes: a coded text block that includes color background information; the lossy coded data packet includes: a coded image block, and the coded text block that does not include color background information.

In an exemplary example, the lossless coded data packet includes: the luminance component in the encoded text block containing the color background information; the lossy coded data packet includes: the coded image block, the coded color code containing the color background information The chroma component in a text block, a text block that does not contain colored background information but the text is colored text, and a text block that does not contain colored background information and the text is achromatic text.

Step 401: After decoding the lossless data packet and filling it in the decoded frame, it is determined that the lossy data packet is an image block or a text block.

In an exemplary example, a lossless decoder can be invoked to decode a lossless data packet.

In an exemplary example, the lossless decoder may include, but is not limited to: ZLIB, GLZ, and other decoders.

In an illustrative example, the decoded frame may be a fully sampled YUV 4:4:4 data frame.

Step 402: Decode the image block and fill it in the decoded frame; decode the text block and compensate the decoded text block according to the chroma information in the data packet to be decoded and fill it in the decoded frame.

In an exemplary example, a lossy decoder can be invoked to decode the lossy data packet.

In an exemplary example, the lossy decoder may include, but is not limited to: X264, X265, and other decoders.

In an exemplary example, before compensating the decoded text block, the method further includes:

Call the decoder to decode the chroma-encoded data packet in the decoded data packet to obtain chroma information.

In an exemplary example, the decoder may include a lossy decoder or a lossless decoder.

The specific implementation of compensating the decoded text block in this step is not used to limit the protection scope of the present application.

In an illustrative example, if the lossy encoded data packet includes: a text block that does not contain colored background information and the text is non-color text. Then, the compensation for the decoded text blocks that do not contain color background information and the text is non-color text includes:

The chroma value 128 is backfilled into the decoded frame according to the Y value of the luminance component. That is to say, the chrominance information at this time is not from the chrominance information in the data packet to be decoded.

In the data decoding method of the present application, the method of direct decoding or decoding after compensation according to different encoding methods of the data packet not only ensures the processing efficiency, but also guarantees the fidelity of certain information such as text information.

In this way, by converting the decoded data frame obtained after decoding from the YUV color space to the RGB color space required for display, the original information before encoding can be obtained and displayed.

An embodiment of the present invention further provides a computer-readable storage medium that stores computer-executable instructions, where the computer-executable instructions are used to perform any one of the data decoding methods described above.

An embodiment of the present invention further provides a data decoding device, including a processor and a memory; wherein, the memory stores a computer program that can run on the processor: for performing any of the steps of the above data decoding method.

5 is a schematic diagram of the composition of the data decoding device of the present application. As shown in FIG. 5, it includes at least: a first processing module, a second processing module, a third processing module, a fourth processing module, a lossy decoder, a decoder, Lossless decoder; where,

The first processing module is configured to determine that the data packet to be decoded includes a lossless data packet or a lossy data packet;

The second processing module is configured to determine that the lossy data packet is an image block or a text block;

Lossy decoder, set to decode the image block and output to the fourth processing module; decode the text block and output to the third processing module;

The decoder is set to decode the chroma information data packet to obtain chroma information;

Lossless decoder, set to decode the lossless data packet and output to the fourth processing module;

The third processing module is set to compensate the decoded text block according to the obtained chrominance information and output it to the fourth processing module;

The fourth processing module is configured to fill the decoded information into the decoded frame.

In an illustrative example, if the lossy encoded data packet includes: a text block that does not contain colored background information and the text is non-color text. Then, the third processing module is specifically configured to compensate the text block that does not contain color background information and the text is achromatic text according to the chroma value 128 of the luminance component Y value. That is to say, the chrominance information at this time is not from the chrominance information in the data packet to be decoded.

In an exemplary example, the decoding end of the present application performs data compensation to different degrees according to different decoded data, and restores the complete YUV 4:4:4 display code stream.

The following uses a cloud desktop scenario to transmit screen content as an example, and a method for obtaining a network topology in the present application will be described in detail in conjunction with specific embodiments.

The first embodiment, taking the coding block to be processed as an image block as an example, includes:

First, the cloud server in the cloud desktop obtains the original desktop pixel data from the shared memory, converts the obtained original desktop pixel data from RGB pixels to YUV format pixels, and blocks the original desktop data according to the coding unit size Dividing to obtain the coding block to be processed; in the first embodiment, it is assumed that it is determined as an image block according to the pixel gradient distribution and color distribution of the current coding block to be processed;

Then, chroma sub-sampling such as YUV4:2:2 sampling is performed on the image block, and the pixel format is sampled from YUV4:4:4 format to YUV4:2:2 format to achieve lossy compression of the image block; The lossy encoder performs lossy encoding on the lossy compressed information to obtain a lossy encoded data packet, and establishes a desktop transmission code stream including the lossy encoded data packet;

After that, after receiving the data packet to be decoded and determining that the lossy encoded data packet includes the image block, the cloud terminal calls the lossy decoder to decode the lossy encoded data packet;

Finally, the decoded pixels are spatially converted into RGB pixels required for final display and displayed.

In the second embodiment, taking the coding block to be processed as a text block containing a colored background as an example, it includes:

First, the server in the cloud desktop obtains the original desktop pixel data from the shared memory, converts the obtained original desktop pixel data from RGB pixels to YUV format pixels, and divides the original desktop data into blocks according to the coding unit size to obtain all The coding block to be processed; in the second embodiment, it is assumed that it is determined as a text block according to the pixel gradient distribution and color distribution of the current coding block to be processed, and it is further determined that the text block contains a colored background according to the chromaticity information Text block

In this case, it is necessary to perform chroma statistics on the current block to obtain chroma information. When the luminance component Y is the same and the chrominance component differs by more than the first threshold set in advance, the luminance component Y is used for offset processing, and the value of the luminance component Y is offset to distinguish different colors.

Then, the chroma component of the current block is chroma sub-sampled, such as YUV4:2:2 sampling, to achieve lossy compression, and the lossy encoder is called for encoding; the full brightness component of the current block is sampled, such as YUV4:4: 4 Sampling to achieve lossless compression and call lossless encoder encoding; call encoder to encode chroma information. Integrate including the encoded lossy encoded data packet, the encoded lossless data packet and the encoded chrominance data packet to obtain the desktop transmission code stream;

After receiving the data packet to be decoded, the cloud terminal calls the lossless decoder to decode the lossless coded data packet; calls the lossy decoder to decode the lossy coded data packet, and decodes the decoded data according to the decoded chroma information The chroma component is compensated;

Finally, the pixels obtained after decoding and compensation are spatially converted into RGB pixels required for final display and displayed.

In the third embodiment, taking the coding block to be processed as a text block that does not contain color background information but the text is color text as an example, it includes:

First, the server in the cloud desktop obtains the original desktop pixel data from the shared memory, converts the obtained original desktop pixel data from RGB pixels to YUV format pixels, and divides the original desktop data into blocks according to the coding unit size to obtain all Describe the coding block to be processed; in the third embodiment, it is assumed that it is determined as a text block according to the pixel gradient distribution and color distribution of the current coding block to be processed, and it is further determined according to the chromaticity information that the text block is an office scene. Common: Text blocks that do not contain a colored background but the text is colored text;

Then, the chroma sub-sampling of the current text block, such as YUV4:2:2 sampling, to achieve lossy compression of the text block, and call the lossy encoder encoding; call the encoder to encode the chrominance information. Integrate the encoded lossy encoded data packet and the encoded chroma data packet to obtain the desktop transmission code stream;

After receiving the data packet to be decoded, the cloud terminal calls the lossy decoder to decode the lossy encoded data packet, and compensates the chroma component of the decoded text block according to the chroma information obtained by decoding;

In the fourth embodiment, taking the coding block to be processed as a text block that does not contain color background information and the text is non-color text as an example, including:

First, the server in the cloud desktop obtains the original desktop pixel data from the shared memory, converts the obtained original desktop pixel data from RGB pixels to YUV format pixels, and divides the original desktop data into blocks according to the coding unit size to obtain all Describe the coding block to be processed; in the third embodiment, it is assumed that it is determined as a text block according to the pixel gradient distribution and color distribution of the current coding block to be processed, and it is further determined according to the chromaticity information that the text block is an office scene. Common: Text blocks that do not contain a colored background and the text is non-colored text;

In this embodiment, since the text block is mainly black and white, and the chroma components are distributed around 128, the statistics of the chroma information can be omitted, and the lossy encoder can be directly encoded after sampling. Therefore, the current text block Chroma sub-sampling, such as YUV4:2:2 sampling, to achieve lossy compression of the text block, and call the lossy encoder encoding; call the encoder to encode the chrominance information. Integrate the encoded lossy encoded data packet and the encoded chroma data packet to obtain the desktop transmission code stream;

After receiving the data packet to be decoded, the cloud terminal calls the lossy decoder to decode the lossy encoded data packet, and realizes the chroma of the decoded text block by backfilling the chroma value 128 according to the Y value of the luminance component Component compensation;

Obviously, those skilled in the art should understand that the above-mentioned modules or steps of the present invention can be implemented by a general-purpose computing device, they can be concentrated on a single computing device, or distributed in a network composed of multiple computing devices Above, optionally, they can be implemented with program code executable by the computing device, so that they can be stored in the storage device to be executed by the computing device, and in some cases, can be in a different order than here The steps shown or described are performed, or they are made into individual integrated circuit modules respectively, or multiple modules or steps among them are made into a single integrated circuit module to achieve. In this way, the present invention is not limited to any specific combination of hardware and software.

The above are only preferred examples of the present invention and are not intended to limit the protection scope of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Industrial applicability

As described above, the data compression method and device, data encoding/decoding method and device provided by the embodiments of the present invention have the following beneficial effects: classify the encoding blocks to be processed before encoding, and for different types of encoding to be processed The block adopts lossy coding or lossless coding, which satisfies the reduction of transmission bandwidth occupation; moreover, the decoding end uses chrominance information to perform necessary color compensation on the data after decoding the coded stream with lossy coding, to ensure the data transmission. Fidelity.

Claims

A data compression method, including:

According to the pixel distribution information, determine whether the coding block to be processed is an image block or a text block;

For the determined text block, obtain chromaticity information, and determine whether the text block contains colored background information according to the chromaticity information;

Lossy compression is performed on the determined image blocks, lossy compression is performed on text blocks that do not contain color background information, and lossless compression is performed on text blocks that contain color background information.
The data compression method according to claim 1, further comprising:

Aiming at the changing area in the original screen data, the pixels of the original screen data are color space converted to obtain the original screen data in the YUV color space;

Dividing the original screen data into blocks according to the size of the coding unit to obtain the coding block to be processed;

Among them, YUV is a pixel format in which the luminance parameter and the chromaticity parameter are separately expressed, Y represents the brightness, and U and V represent the chromaticity.
The data compression method according to claim 1 or 2, wherein the determining that the encoding block to be processed is an image block or a text block includes:

According to the gradient characteristics and color distribution information of the pixel distribution inside the coding block to be processed, the image block and the text block are distinguished from the coding block to be processed.
The data compression method according to claim 1 or 2, wherein the determining whether the text block contains colored background information includes:

Statistics on the color types of a single coding unit to obtain chromaticity information;

When the counted color type exceeds the preset first threshold, the text block containing the color background information is determined; when the counted color type is lower than the preset first threshold, the text block is determined not to contain Text block with colored background information.
The data compression method according to claim 1, when the text block does not contain color background information, the method further comprises:

If most of the pixel chromaticity of the text block is distributed within a preset error range of a preset value, it is determined that the text block is a text block that does not contain colored background information but the text is colored text;

If the pixel chromaticity values of the text block are all distributed within a preset error range of a preset value, it is determined that the text block is a text block that does not contain colored background information and the text is non-color text.
The data compression method according to claim 1, wherein the lossy compression of the image block includes:

Sub-sampling the image block.
The data compression method according to claim 1, wherein the lossy compression of the text block that does not contain color background information includes:

Sub-sampling the text block that does not contain color background information.
The data compression method according to claim 1, wherein the lossless compression of the text block containing colored background information includes:

Fully sampling the text block containing colored background information;

Alternatively, for the text block containing color background information, the luminance component is fully sampled, and the chrominance component is sub-sampled.
The data compression method according to claim 5, wherein the sub-sampling of text blocks that do not contain color background information to achieve lossy compression includes:

Sub-sampling the text block that does not contain color background information but the text is color text;

Sub-sampling the text block that does not contain color background information and the text is non-color text.
The data compression method according to any one of claims 6 to 9, wherein the subsampling includes: YUV4:2:2 sampling; and the full sampling includes: YUV4:4:4 sampling.
A data encoding method, including:

According to the pixel distribution information, determine whether the coding block to be processed is an image block or a text block;

For the determined text block, obtain chromaticity information, and determine whether the text block contains colored background information according to the chromaticity information;

Lossy compression of the determined image blocks, lossy compression of text blocks that do not contain color background information, and lossless compression of text blocks that contain color background information;

Perform lossless encoding on the information after lossless compression, lossy encoding on the information after lossy compression, and encode chrominance information to complete the encoding of the encoding block to be processed.
The data encoding method according to claim 11, wherein the determining that the encoding block to be processed is an image block or a text block includes:

According to the gradient characteristics and color distribution information of the pixel distribution inside the coding block to be processed, the image block and the text block are distinguished from the coding block to be processed.
The data encoding method according to claim 11, wherein the determining whether the text block contains colored background information includes:

Statistics on the color types of a single coding unit to obtain chromaticity information;

When the counted color type exceeds the preset first threshold, the text block containing the color background information is determined; when the counted color type is lower than the preset first threshold, the text block is determined not to contain Text block with colored background information.
The data encoding method according to claim 11, when the text block does not contain color background information, the method further comprises:

If most of the pixel chromaticity of the text block is distributed within a preset error range of a preset value, it is determined that the text block is a text block that does not contain colored background information but the text is colored text;

If the pixel chromaticity values of the text block are all distributed within a preset error range of a preset value, it is determined that the text block is a text block that does not contain colored background information and the text is non-color text.
The data compression method according to claim 11, wherein

The lossy compression of the image block includes:

Sub-sampling the image block;

The lossy compression of text blocks that do not contain color background information includes:

Sub-sampling the text block that does not contain color background information;

The lossless compression of text blocks containing colored background information includes:

Fully sampling the text block containing colored background information; or,

For the text block containing color background information, the luma component is fully sampled, and the chroma component is sub-sampled.
The data encoding method according to claim 14, wherein the sub-sampling of text blocks that do not contain color background information to achieve lossy compression includes:

Sub-sampling the text block that does not contain color background information but the text is color text;

Sub-sampling the text block that does not contain color background information and the text is non-color text.
The data encoding method according to claim 15 or 16, wherein the subsampling includes: YUV4:2:2 sampling; the full sampling includes: YUV4:4:4 sampling.
The data encoding method according to claim 11, wherein the lossless encoding of the information after lossless compression, the lossy encoding of the information after lossy compression, and the encoding of chroma information include:

Calling a lossless encoder to perform the lossless encoding on the lossless compressed information, calling a lossy encoder to perform the lossy encoding on the lossy compressed information, and calling a lossless encoder to perform the chroma information coding.
The data encoding method according to claim 11, further comprising:

The identification information is used to distinguish different types of the compressed information, different types of the encoded data packets, and the encoded chrominance information.
The data encoding method according to claim 19, wherein the identification information is carried in a network sampling layer NAL unit.
A computer-readable storage medium storing computer-executable instructions for performing the data compression method according to any one of claims 1 to 10, and/or claim 11 to claims The data encoding method according to any one of 20.
A data compression device includes a processor and a memory; wherein the memory stores a computer program that can run on the processor: for performing the steps of the data compression method according to any one of claims 1 to 10.
A data encoding device includes a processor and a memory; wherein the memory stores a computer program executable on the processor: for performing the steps of the data encoding method according to any one of claims 11 to 20.
A data decoding method, including:

Obtain the data packet to be decoded, and determine that the data packet to be decoded includes a lossless data packet or a lossy data packet;

After decoding the lossless data packet and filling it in the decoded frame, it is determined that the lossy data packet is an image block or a text block;

Decode the image block and fill it in the decoded frame; decode the text block and compensate the decoded text block according to the chroma information in the data packet to be decoded and fill it in the decoded frame.
The data decoding method according to claim 24, wherein the data packet to be decoded includes any one or any combination of the following: a lossy encoded data packet, a lossless encoded data packet, and a chroma encoded data packet.
The data decoding method according to claim 25, wherein

The lossless coded data packet includes: a coded text block containing colored background information;

The lossy encoded data packet includes: an encoded image block and an encoded text block that does not contain color background information.
The data decoding method according to claim 25, wherein

The lossless coded data packet includes: the luminance component in the coded text block containing colored background information;

The lossy coded data packet includes: a coded image block, a chroma component in the coded text block containing colored background information, a text block that does not contain color background information but the text is color text, and does not contain color background information And the text is a block of non-color text.
The data decoding method according to claim 24, before the compensating the decoded text block, further comprising:

Call the decoder to decode the chroma-encoded data packet in the data packet to be decoded to obtain chroma information.
The data decoding method according to claim 28, wherein the lossy encoded data packet includes a text block that does not contain color background information and the text is achromatic text; and the compensating for the decoded text block includes:

The chroma value 128 is backfilled into the decoded frame according to the luminance component Y value.
The data decoding method according to claim 28, wherein the decoded frame is a fully sampled YUV 4:4:4 data frame.
A computer-readable storage medium storing computer-executable instructions for performing the data decoding method according to any one of claims 24 to 30.
A data decoding device includes a processor and a memory; wherein the memory stores a computer program executable on the processor: for performing the steps of the data decoding method according to any one of claims 24 to 30.