Video Encoding Transformation Matrix Selection

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Solution Overview

Problem

Existing video encoding technologies, such as Mode Dependent Directional Transform (MDDT), are not accurate enough in selecting transformation matrices for intra-frame prediction modes, leading to inefficient encoding due to varying statistical features of residual data despite the same prediction mode.

Innovation Solution

A method and device for encoding and decoding videos that select the best transformation matrixes based on intra-frame prediction modes and rate-distortion criteria to optimize transform-coding of prediction residuals, improving encoding efficiency by matching transformation matrices to the specific features of each residual block.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If one intra-frame prediction mode corresponds to a set of transformation matrixes (MDDT technology), then the transformation complexity is reduced by separating rows from columns, but the encoding efficiency is insufficient because the statistical features of residual data still differ obviously even within the same prediction mode

Engineering Contradiction:
Improvetransformation complexityVSAvoidencoding efficiency
Core Design Contradiction:
Device complexityVSProductivity

Solution Approach 1:

The patent segments the transformation matrix selection process by dividing residual blocks into different categories based on their statistical features (e.g., variance, energy distribution). Instead of using a single transformation matrix for all residual blocks within a prediction mode, the patent selects different transformation matrices for different segments of residual blocks, thereby improving encoding efficiency while maintaining manageable complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces dynamic transformation matrix selection where the transformation matrix is not fixed for a given prediction mode but is dynamically chosen based on the actual statistical characteristics of each residual block. This dynamic adaptation allows the system to optimize encoding efficiency for each specific residual block while keeping the overall system complexity controlled through predefined matrix sets.

Inventive Principle:
Principle #15Dynamics

2Productivity

If multiple candidate transformation matrixes are selected based on rate-distortion criteria for each residual block, then encoding efficiency is improved by matching transformation matrices to specific features, but the device complexity and computational load increase

Engineering Contradiction:
Improveencoding efficiencyVSAvoiddevice complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent applies preliminary action by pre-defining multiple candidate transformation matrices and organizing them into sets before the actual encoding process. During encoding, the system only needs to select from these pre-prepared matrices based on simple criteria (such as residual block variance thresholds), rather than computing optimal matrices in real-time. This significantly reduces computational complexity while maintaining the benefit of adaptive matrix selection.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent changes parameters by using simplified selection criteria (such as variance thresholds or energy metrics) to choose transformation matrices, rather than performing complex rate-distortion optimization for each block. This parameter-based selection approach maintains encoding efficiency improvements while reducing the computational burden and device complexity.

Inventive Principle:
Principle #35Parameter changes

3Device complexity

If the same transformation matrix is used for all prediction modes, then the device complexity is reduced, but the encoding efficiency is lost due to not adapting to different statistical features of residual data

Engineering Contradiction:
Improvedevice complexityVSAvoidencoding efficiency
Core Design Contradiction:
Device complexityVSProductivity

Solution Approach 1:

The patent applies local quality by assigning different transformation matrices to different local characteristics of residual data. Instead of using a uniform transformation matrix for all prediction modes and all residual blocks, the patent selects transformation matrices that are locally adapted to the specific statistical features of each residual block, thereby improving encoding efficiency without requiring a complete redesign of the transformation system.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent achieves universality by creating a set of transformation matrices that can serve multiple prediction modes and multiple types of residual blocks. Rather than having dedicated transformation matrices for each prediction mode (which would increase complexity), the patent designs a universal set of matrices that can be selectively applied based on residual block characteristics, maintaining both simplicity and adaptability.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentUS9723313B2Method and device for encoding and decoding videos using a best transformation matrix among multiple transformation matrices
Publication Date: 2017.08.01 HUAWEI TECH CO LTD
  • US9723313B2 patent drawing
  • US9723313B2 patent drawing
  • US9723313B2 patent drawing

AI summary

The embodiments of the present invention provide a method and a device for encoding and decoding videos, and relate to the communication field, and an efficient transformation matrix corresponding to features of each residual block is selected for transformation, which therefore improves encoding efficiency. The solution provided in an embodiment of the present invention is: generating a prediction residual according to input video data; selecting a set of best transformation matrixes among multiple candidate transformation matrixes according to an intra-frame prediction mode and rate-distortion criteria to perform transform-coding on the prediction residual and obtain a transformation result; and generating an encoded stream according to the transformation result and selected transformation matrix index information.