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EP-4740477-A1 - METHODS AND APPARATUS FOR VIDEO CODING IMPROVEMENT BY MULTIPLE MODELS

EP4740477A1EP 4740477 A1EP4740477 A1EP 4740477A1EP-4740477-A1

Abstract

A method and apparatus for coding colour pictures or video using coding tools including one or more cross component models related modes are disclosed. According to this method, input data associated with a current block comprising a first-colour block and a second-colour block is received, wherein the input data comprises pixel data to be encoded at an encoder side or data associated with the current block to be decoded at a decoder side. A unified candidate list used for a first coding type and a second coding type is determined, wherein the unified candidate list comprises at least one candidate associated with at least one cross-component model. The second-colour block is encoded or decoded using the unified candidate list, wherein cross-component prediction data is generated for the second-colour block according to said at least one candidate associated with said at least one cross-component model when said at least one candidate is selected.

Inventors

  • CHIANG, Man-Shu
  • TSENG, HSIN-YI
  • TSAI, CHIA-MING
  • CHUANG, CHENG-YEN
  • HSU, CHIH-WEI
  • CHEN, YI-WEN

Assignees

  • MEDIATEK INC.

Dates

Publication Date
20260513
Application Date
20240704

Claims (10)

  1. A method of coding colour pictures or video using coding tools including one or more cross component models related modes, the method comprising: receiving input data associated with a current block comprising a first-colour block and a second-colour block, wherein the input data comprises pixel data to be encoded at an encoder side or data associated with the current block to be decoded at a decoder side; determining a unified candidate list used for a first coding type and a second coding type, wherein the unified candidate list comprises at least one candidate associated with at least one cross-component model; and encoding or decoding the second-colour block using the unified candidate list, wherein cross-component prediction data is generated for the second-colour block according to said at least one candidate associated with said at least one cross-component model when said at least one candidate is selected.
  2. The method of Claim 1, wherein the unified candidate list comprises one or more first candidates from intra blocks, one or more second candidates from inter blocks, or both.
  3. The method of Claim 1, wherein said cross-component prediction data is generated by blending multiple-hypotheses of cross-component predictions.
  4. The method of Claim 3, wherein multiple models are used to generate the multiple-hypotheses of cross-component predictions respectively.
  5. The method of Claim 1, wherein said at least one candidate is generated by using multiple cross-component models.
  6. The method of Claim 5, wherein said at least one candidate is generated by combining the multiple cross-component models into one final cross-component model.
  7. The method of Claim 5, wherein said at least one candidate is generated by selecting a first model associated with a first candidate and a second model associated with a second candidate.
  8. The method of Claim 1, wherein said at least one candidate with said at least one cross-component model comprises model parameters associated with CCLM (Cross-Component Linear Model) , MMLM (Multiple Model CCLM) , GLM (Gradient Linear Model) , CCCM Convolutional Cross-Component Model) , or a derived model.
  9. The method of Claim 8, wherein the derived model is generated using motion compensated results.
  10. An apparatus for coding colour pictures or video using coding tools including one or more cross component models related modes, the apparatus comprising one or more electronic circuits or processors arranged to: receive input data associated with a current block comprising a first-colour block and a second-colour block, wherein the input data comprises pixel data to be encoded at an encoder side or data associated with the current block to be decoded at a decoder side; determine a unified candidate list used for a first coding type and a second coding type, wherein the unified candidate list comprises at least one candidate associated with at least one cross-component model; and encode or decode the second-colour block using the unified candidate list, wherein cross-component prediction data is generated for the second-colour block according to said at least one candidate associated with said at least one cross-component model when said at least one candidate is selected.

Description

METHODS AND APPARATUS FOR VIDEO CODING IMPROVEMENT BY MULTIPLE MODELS CROSS REFERENCE TO RELATED APPLICATIONS The present invention is a non-Provisional Application of and claims priority to U.S. Provisional Patent Application No. 63/511,921, filed on July 5, 2023. The U.S. Provisional Patent Application is hereby incorporated by reference in its entirety. FIELD OF THE INVENTION The present invention relates to video coding system. In particular, the present invention relates to coding for a chroma component using cross-component prediction. BACKGROUND AND RELATED ART Versatile video coding (VVC) is the latest international video coding standard developed by the Joint Video Experts Team (JVET) of the ITU-T Video Coding Experts Group (VCEG) and the ISO/IEC Moving Picture Experts Group (MPEG) . The standard has been published as an ISO standard: ISO/IEC 23090-3: 2021, Information technology -Coded representation of immersive media -Part 3: Versatile video coding, published Feb. 2021. VVC is developed based on its predecessor HEVC (High Efficiency Video Coding) by adding more coding tools to improve coding efficiency and also to handle various types of video sources including 3-dimensional (3D) video signals. Fig. 1A illustrates an exemplary adaptive Inter/Intra video encoding system incorporating loop processing. For Intra Prediction 110, the prediction data is derived based on previously coded video data in the current picture. For Inter Prediction 112, Motion Estimation (ME) is performed at the encoder side and Motion Compensation (MC) is performed based on the result of ME to provide prediction data derived from other picture (s) and motion data. Switch 114 selects Intra Prediction 110 or Inter Prediction 112 and the selected prediction data is supplied to Adder 116 to form prediction errors, also called residues. The prediction error is then processed by Transform (T) 118 followed by Quantization (Q) 120. The transformed and quantized residues are then coded by Entropy Encoder 122 to be included in a video bitstream corresponding to the compressed video data. The bitstream associated with the transform coefficients is then packed with side information such as motion and coding modes associated with Intra prediction and Inter prediction, and other information such as parameters associated with loop filters applied to underlying image area. The side information associated with Intra Prediction 110, Inter prediction 112 and in-loop filter 130, is provided to Entropy Encoder 122 as shown in Fig. 1A. When an Inter-prediction mode is used, a reference picture or pictures have to be reconstructed at the encoder end as well. Consequently, the transformed and quantized residues are processed by Inverse Quantization (IQ) 124 and Inverse Transformation (IT) 126 to recover the residues. The residues are then added back to prediction data 136 at Reconstruction (REC) 128 to reconstruct video data. The reconstructed video data may be stored in Reference Picture Buffer 134 and used for prediction of other frames. As shown in Fig. 1A, incoming video data undergoes a series of processing in the encoding system. The reconstructed video data from REC 128 may be subject to various impairments due to a series of processing. Accordingly, in-loop filter 130 is often applied to the reconstructed video data before the reconstructed video data are stored in the Reference Picture Buffer 134 in order to improve video quality. For example, deblocking filter (DF) , Sample Adaptive Offset (SAO) and Adaptive Loop Filter (ALF) may be used. The loop filter information may need to be incorporated in the bitstream so that a decoder can properly recover the required information. Therefore, loop filter information is also provided to Entropy Encoder 122 for incorporation into the bitstream. In Fig. 1A, Loop filter 130 is applied to the reconstructed video before the reconstructed samples are stored in the  reference picture buffer 134. The system in Fig. 1A is intended to illustrate an exemplary structure of a typical video encoder. It may correspond to the High Efficiency Video Coding (HEVC) system, VP8, VP9, H. 264 or VVC. The decoder, as shown in Fig. 1B, can use similar or portion of the same functional blocks as the encoder except for Transform 118 and Quantization 120 since the decoder only needs Inverse Quantization 124 and Inverse Transform 126. Instead of Entropy Encoder 122, the decoder uses an Entropy Decoder 140 to decode the video bitstream into quantized transform coefficients and needed coding information (e.g. ILPF information, Intra prediction information and Inter prediction information) . The Intra prediction 150 at the decoder side does not need to perform the mode search. Instead, the decoder only needs to generate Intra prediction according to Intra prediction information received from the Entropy Decoder 140. Furthermore, for Inter prediction, the decoder only needs to perform motion compensation (MC 152) accord