Conditional Quantization Parameter Signaling for Video Coding Efficiency

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Solution Overview

Problem

Current video coding standards, such as HEVC, face challenges in efficiently signaling quantization parameters (QPs) for various block partitioning methods, leading to increased coding complexity and bit rate, especially when dealing with non-square blocks and combined partitioning structures like Quad-Tree-Binary-Tree (QTBT).

Innovation Solution

The proposed solution involves conditioning the signaling of QP information based on the area or combined depth of coding blocks, where QP information is signaled only for blocks exceeding a minimum block area or depth threshold, and shared QP information is used for groups of blocks, reducing unnecessary signaling and bit rate. This approach applies to quad-tree, binary-tree, QTBT, and triple-tree partitioning methods, allowing for adaptive quantization in video coding systems.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If QP information is signaled for all coding blocks, then quantization precision is maintained, but bit rate increases

Engineering Contradiction:
Improvequantization precisionVSAvoidbit rate
Core Design Contradiction:
Measurement precisionVSQuantity of substance

Solution Approach 1:

The patent applies local quality by differentiating QP signaling based on block characteristics. Large blocks (area >= minimum block area) receive explicit QP signaling to maintain precision where needed, while small blocks derive QP from neighboring blocks to reduce bit rate. This selective approach ensures quantization precision is maintained only where it provides meaningful improvement.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent implements partial action by signaling QP information only for a subset of coding blocks rather than all blocks. Specifically, QP is explicitly signaled only for large blocks that meet the minimum block area threshold, while small blocks use derived QP values from neighbors, achieving sufficient quantization quality without excessive bit rate consumption.

Inventive Principle:
Principle #16Partial or excessive action

2Measurement precision

If QP information is signaled for all coding blocks, then quantization quality is maintained, but coding complexity increases

Engineering Contradiction:
Improvequantization qualityVSAvoidcoding complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent reduces coding complexity by applying different QP handling strategies to different block types. Large blocks undergo full QP signaling and processing, while small blocks use simplified QP derivation from neighboring blocks, reducing the overall computational burden and complexity of the encoding/decoding process.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent implements partial action by performing complete QP signaling only for large blocks that require it for quality, while using simpler QP derivation for small blocks. This selective approach maintains quantization quality where necessary while reducing coding complexity for blocks where full signaling is unnecessary.

Inventive Principle:
Principle #16Partial or excessive action

3Measurement precision

If minimum block area threshold is set low, then more blocks receive explicit QP signaling improving quality, but bit rate increases

Engineering Contradiction:
Improvequantization qualityVSAvoidbit rate
Core Design Contradiction:
Measurement precisionVSQuantity of substance

Solution Approach 1:

The patent uses parameter changes by adjusting the minimum block area threshold to optimize the balance between quality and bit rate. The threshold acts as a controllable parameter that determines which blocks receive explicit QP signaling, allowing systematic adjustment of the quality-bit rate tradeoff based on specific application requirements.

Inventive Principle:
Principle #35Parameter changes

4Quantity of substance

If minimum block area threshold is set high, then fewer blocks receive explicit QP signaling reducing bit rate, but quantization quality deteriorates

Engineering Contradiction:
Improvebit rateVSAvoidquantization quality
Core Design Contradiction:
Quantity of substanceVSMeasurement precision

Solution Approach 1:

The patent employs parameter changes by adjusting the minimum block area threshold to control the balance between bit rate reduction and quality maintenance. By setting the threshold appropriately, the system achieves bit rate reduction through selective QP signaling while maintaining adequate quantization quality for blocks that receive explicit QP values.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3453172B1Methods and apparatuses of video data processing with conditionally quantization parameter information signaling
Publication Date: 2023.08.09 HFI INNOVATION INC
  • EP3453172B1 patent drawingFigure 1~2
  • EP3453172B1 patent drawingFigure 3
  • EP3453172B1 patent drawingFigure 4A~4B

AI summary

Processing methods and apparatuses for video data of a color component comprise receiving input data associated with a current coding block (CB) in a current slice, where the video data is partitioned into multiple CBs according to a partitioning method. A Quantization Parameter (QP) minimum block area or a depth flag is determined and an area of the current CB according to a width and a height or a combined depth of the current CB is calculated and compared with the QP minimum block area or the depth flag. Signaling of QP information for the current CB is conditioned by the comparing result. The QP information for the current CB is used to quantize a residual signal of the current CB or recovering a quantized residual signal of the current CB.