RGB Mapping for 4:4:4 Video Coding Efficiency

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Solution Overview

Problem

Existing video compression methods, such as those in the VVC standard, are not adapted to handle RGB content efficiently, as they were designed for YUV formats, leading to suboptimal coding efficiency for 4:4:4 RGB video content.

Innovation Solution

Adapting Luma Mapping with Chroma Scaling (LMCS) to RGB content by applying RGB mapping to all color components, enabling adaptive color transform and chroma residual scaling, and signaling specific syntax elements to control the mapping processes, allowing for dynamic range adjustment of RGB components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If Luma Mapping with Chroma Scaling (LMCS) is applied to YUV content, then coding efficiency is improved, but the method is not adapted to RGB content

Engineering Contradiction:

Improvecoding efficiencyVSAvoidadaptability to RGB content

Core Design Contradiction:

ProductivityVSAdaptability or versatility

Solution Approach 1:

The patent extends the LMCS tool to handle both YUV and RGB color spaces by implementing a unified mapping mechanism that can process different color formats. The system determines the color space format and applies appropriate mapping operations (luma mapping for YUV, RGB mapping for RGB) to achieve universal compatibility across different content types while maintaining high coding efficiency.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent modifies the mapping parameters and operations based on the detected color space format. For YUV content, luma mapping parameters are applied to the Y component, while for RGB content, RGB mapping parameters are applied to the R, G, and B components. This parameter adaptation enables the same tool to optimize coding efficiency for different color spaces without requiring separate processing paths.

Inventive Principle:

Principle #35Parameter changes

2Productivity

If RGB mapping is applied to adjust dynamic range of color components, then coding efficiency for RGB content is improved, but device complexity increases

Engineering Contradiction:

Improvecoding efficiency for RGB contentVSAvoidcomplexity of mapping implementation

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The patent divides the mapping process into distinct operational segments: format detection phase, mapping parameter selection phase, and mapping application phase. By segmenting these functions and using flag-based control mechanisms to indicate when mapping should be applied, the system reduces implementation complexity while maintaining the benefits of dynamic range adjustment for RGB content.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent implements dynamic mapping control where the mapping operation is activated or deactivated based on signaled flags in the bitstream. This dynamic enable/disable mechanism allows the system to adapt to different content types and coding scenarios, reducing complexity by only applying the more complex RGB mapping when necessary rather than always applying it unconditionally.

Inventive Principle:

Principle #15Dynamics

Data Source

PatentUS20240195991A1Adapting luma mapping with chroma scaling to 4:4:4 RGB image content

Publication Date: 2024.06.13 INTERDIGITAL CE PATENT HOLDINGS SAS

AI summary

At least a method and an apparatus are presented for efficiently encoding or decoding video by adapting Luma mapping with Chroma scaling for 4:4:4 RGB content. For example, a format of an image data of a video to encode is determined to be RGB format; and responsively a RGB mapping is applied to at least one of the color components of the image data wherein a RGB mapping adjusts the dynamic range of a color component of an image data in RGB format. Then, the video is encoded based on the at least one RGB mapped color component.