CN-116389741-B - Method for encoding a current block of image or video data

Abstract

A method for encoding a current block of image or video data is disclosed. The present disclosure relates to sparse matrix representation using non-zero coefficient boundaries. Sparse matrix representation of image or video data for encoding or decoding uses boundaries of non-zero coefficients within the image or video data. The bounding box encloses each non-zero coefficient within the image or video block. The coefficients enclosed within the bounding box are encoded into the bitstream together with size information that can be used to identify the bounding box within the image or video block during decoding. Coefficients not enclosed in the bounding box are not specifically encoded in the bitstream. The size information represents one or more of a shape, size, or position within an image or video block of the bounding box. The bounding box may be identified according to a scan order for processing coefficients within the image or video block. The bounding box may be rectangular or non-rectangular.

Inventors

• Pascal maximino
• Vincent labo

Assignees

• 谷歌有限责任公司

Dates

Publication Date

20260505

Application Date

20200909

Priority Date

20191224

Claims (20)

1. 1. A method for decoding an encoded block of image or video data, the method comprising: decoding size information of a bounding box of the encoded block from a bitstream; decoding syntax elements corresponding to non-zero value coefficients enclosed within the bounding box from the bitstream using the size information, and wherein the syntax elements are arranged in a one-dimensional sequence format; Dequantizing the syntax element to generate transform data, wherein the transform data comprises coefficients arranged in a two-dimensional matrix format; Inverse transforming the transformed data to produce decoded data, and Outputting the decoded data for storage or display.
2. 2. The method of claim 1, wherein decoding the syntax element comprises: The size information is used to determine the location of the non-zero value coefficients within the encoded block.
3. 3. The method according to claim 1, comprising: A syntax element is decoded from the bitstream indicating that the bounding box is used to encode the encoded block.
4. 4. A method according to claim 3, wherein the syntax element is decoded from a block header corresponding to the encoded block.
5. 5. A method according to claim 3, wherein the syntax element is decoded from a picture header or a video frame header corresponding to a picture or video frame comprising the encoded block.
6. 6. The method of claim 1, wherein the bounding box is based on a position of the non-zero value coefficients according to a scan order used to encode the encoded block.
7. 7. The method of claim 1, wherein the bounding box has a non-rectangular shape.
8. 8. The method of claim 1, wherein at least some zero-valued coefficients of the encoded block are outside of the bounding box.
9. 9. The method of claim 1, wherein the size information corresponds to one or both of a shape of the bounding box or a size of the bounding box.
10. 10. The method of claim 1, wherein the bounding box encloses only non-zero value coefficients of the encoded block.
11. 11. A method for decoding an encoded block of image or video data, the method comprising: Decoding size information of a bounding box of the encoded block from a bitstream, the bounding box corresponding to a boundary of a non-zero value coefficient; decoding syntax elements including non-zero value coefficients enclosed within the bounding box from the bitstream using the size information; Generating decoded data by inverse quantizing and inverse transforming syntax elements, and Outputting the decoded data for storage or display.
12. 12. The method of claim 11, wherein all non-zero value coefficients of the encoded block are enclosed within the bounding box and all coefficients of the encoded block outside the bounding box are zero value coefficients.
13. 13. The method of claim 11, wherein the syntax elements are arranged in a one-dimensional sequence format and the decoded data are arranged in a two-dimensional matrix format.
14. 14. The method of claim 11, comprising: Determining whether a value of a syntax element encoded to the bitstream indicates that the bounding box is used for encoding the encoded block, and The size information is decoded from the bitstream in response to determining that the value of the syntax element indicates that the bounding box is used to encode the encoded block.
15. 15. The method of claim 11, wherein the size information corresponds to one or both of a shape of the bounding box or a size of the bounding box.
16. 16. A method for decoding an encoded block of image or video data, the method comprising: identifying size information of a bounding box of the encoded block; identifying syntax elements corresponding to coefficients enclosed within the bounding box, wherein the syntax elements are arranged in a one-dimensional sequence format; decoding the encoded block by inverse quantizing and inverse transforming the syntax element to generate decoded data, wherein the decoded data is arranged in a two-dimensional matrix format, and Outputting the decoded data for storage or display.
17. 17. The method of claim 16, wherein all non-zero value coefficients of the encoded block are enclosed within the bounding box and all coefficients of the encoded block outside the bounding box are zero value coefficients.
18. 18. The method of claim 16, wherein the size information and the syntax element are decoded from a bitstream comprising the encoded block.
19. 19. The method of claim 16, wherein the size information is identified based on a value of a syntax element encoded to a bitstream, the bitstream including the encoded block indicating that the bounding box is used to encode the encoded block.
20. 20. The method of claim 16, wherein the bounding box is based on locations of non-zero value coefficients according to a scan order used to encode the encoded block.

Description

Method for encoding a current block of image or video data Description of the division The application belongs to a divisional application of Chinese application patent application No.202010940205.3 with the application date of 2020, 9 months and 9 days. Technical Field The present disclosure relates to sparse matrix representation using non-zero coefficient boundaries. Background Image content represents a large amount of online content. The web page may include multiple images, and most of the time and resources spent rendering the web page are dedicated to rendering those images for display. The amount of time and resources required to receive and render an image for display depends in part on the manner in which the image is encoded. In this way, the image, and thus the web page including the image, may be rendered faster by reducing the overall data size of the image. Various schemes have been proposed to reduce the overall data size of the image, including encoding or decoding techniques. The digital video stream may represent video using a series of frames or still images. Digital video may be used in a variety of applications including, for example, video conferencing, high definition video entertainment, video advertising, or sharing of user-generated video. Digital video streams may contain large amounts of data and consume large amounts of computing or communication resources of a computing device for processing, transmitting, or storing video data. Various schemes have been proposed to reduce the amount of data in a video stream, including encoding or decoding techniques. Disclosure of Invention Systems and techniques for image or video encoding using sparse matrix representations that use boundaries of non-zero coefficients are particularly disclosed herein. A method for encoding an image block according to an embodiment of the present disclosure includes transforming data of the image block to generate transformed image data, quantizing the transformed image data to generate quantized image data, wherein the quantized image data includes coefficients arranged in a two-dimensional matrix, identifying a bounding box of non-zero value coefficients of the quantized image data enclosed within the two-dimensional matrix, wherein zero value coefficients of the quantized image data are located outside the bounding box within the two-dimensional matrix, entropy encoding the non-zero value coefficients enclosed within the bounding box into an encoded bitstream, and including size information of the bounding box in the encoded bitstream. A method for decoding an encoded image block according to an embodiment of the present disclosure includes decoding size information of a bounding box from an encoded bitstream including the encoded image block, decoding syntax elements representing the encoded image block from the encoded bitstream using the size information, wherein the syntax elements correspond to non-zero value coefficients of image data enclosed within the bounding box during encoding of the image data, wherein the syntax elements are arranged in a format other than a two-dimensional matrix format, dequantizing the syntax elements to generate transformed image data, wherein the transformed image data includes coefficients arranged in a two-dimensional matrix, inverse transforming the transformed image data to generate decoded image data, and outputting the decoded image data for storage or display. A method for encoding a video block according to an embodiment of the present disclosure includes generating a prediction block for data of the video block, generating a prediction residual for the data of the video block using the prediction block, transforming the prediction residual to generate a transform coefficient, quantizing the transform coefficient to generate a quantized transform coefficient, wherein the quantized transform coefficient is arranged in a two-dimensional matrix, identifying a bounding box of non-zero value coefficients of the quantized transform coefficient enclosed within the two-dimensional matrix, wherein zero value coefficients of the quantized transform coefficient are located outside the bounding box within the two-dimensional matrix, entropy encoding the non-zero value coefficients enclosed within the bounding box into an encoded bitstream, and including size information of the bounding box in the encoded bitstream. A method for decoding an encoded video block according to an embodiment of the present disclosure includes decoding size information of a bounding box from an encoded bitstream including the encoded image block, decoding syntax elements representing the encoded video block from the encoded bitstream using the size information, wherein the syntax elements correspond to non-zero value coefficients of the video data enclosed within the bounding box during encoding of the video data, wherein the syntax elements are arranged in a format other than a two-dimensional