18312077. COEFFICIENT-BASED TRANSFORM AND MODE SIGNALING simplified abstract (Apple Inc.)

COEFFICIENT-BASED TRANSFORM AND MODE SIGNALING

Organization Name

Apple Inc.

Inventor(s)

Alican Nalci of Cupertino CA (US)

Yunfei Zheng of Santa Clara CA (US)

Hilmi E. Egilmez of Santa Clara CA (US)

Yeqing Wu of Cupertino CA (US)

Yixin Du of Cupertino CA (US)

Alexis Tourapis of Los Gatos CA (US)

Jun Xin of San Jose CA (US)

Hsi-Jung Wu of San Jose CA (US)

COEFFICIENT-BASED TRANSFORM AND MODE SIGNALING - A simplified explanation of the abstract

This abstract first appeared for US patent application 18312077 titled 'COEFFICIENT-BASED TRANSFORM AND MODE SIGNALING

Simplified Explanation

Techniques are described for signaling transform mode selections in video coding based on information derived from coefficient samples in a given transform unit (TU) or prediction unit (PU). This information can constrain or modify the signaling of certain syntax elements at the coding block (CB), TU, or PU levels.

• The spatial locations, patterns, and correlation of decoded coefficients can be used to disable or constrain various syntax elements such as transform type, related flags/indices, secondary transform modes/flags indices, residual coding mode, intra and inter prediction modes, and scanning order.
• If coefficient samples match a desired spatial pattern or have other desired properties, default transform types, secondary transform types, intra and inter prediction modes, or other block level modes can be inferred at the decoder side.
• Similar ideas can be extended to infer intra-block copy (IBC) flags/modes/indices from coefficient samples or to infer flags and modes related to predictive coding techniques such as block-wise differential pulse code modulation (BDPCM), horizontal and vertical BDPCM modes, palette mode syntax, and other block level flags/indices.

Potential applications of this technology:

• Video coding systems and algorithms that can adaptively select transform modes based on coefficient samples, leading to improved compression efficiency.
• Efficient signaling of transform mode selections in video coding, reducing the amount of transmitted information and improving decoding speed.
• Adaptive video coding techniques that can dynamically adjust transform modes based on the spatial patterns and correlation of decoded coefficients, leading to better video quality.

Problems solved by this technology:

• Inefficient signaling of transform mode selections in video coding, resulting in increased bit rate and decoding complexity.
• Limited adaptability of video coding systems to different types of video content, leading to suboptimal compression efficiency.
• Difficulty in inferring transform modes and related syntax elements from coefficient samples, hindering the development of efficient video coding algorithms.

Benefits of this technology:

• Improved compression efficiency in video coding, leading to reduced bit rate and storage requirements.
• Enhanced video quality through adaptive selection of transform modes based on coefficient samples.
• Faster decoding speed due to efficient signaling and inference of transform modes and related syntax elements.

Original Abstract Submitted

Techniques are described for express and implied signaling of transform mode selections in video coding. Information derived from coefficient samples in a given transform unit (TU) or prediction unit (PU) may constrain or modify signaling of certain syntax elements at the coding block (CB), TU, or PU levels. For instance, based on the spatial locations of decoded coefficients, the spatial patterns of coefficients, or the correlation with the coefficients in neighboring blocks, various syntax elements such as the transform type and related flags/indices or secondary transform modes/flags indices, a residual coding mode, intra and inter prediction modes, and scanning order may be disabled or constrained. In another case, if the coefficient samples match a desired spatial pattern or have other desired properties then a default transform type, a default secondary transform type, a default intra and inter prediction mode or other block level modes may be inferred at the decoder side. Similar ideas may be extended to infer intra-block copy (IBC) flags/modes/indices from coefficient samples, or to infer flags and modes related to predictive coding techniques such as block-wise differential pulse code modulation (BDPCM), i.e., horizontal and vertical BDPCM modes, palette mode syntax and other block level flags/indices.