Implicit Masked Blending Mode for Video Prediction

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Solution Overview

Problem

Current video coding methods, such as those using High-Efficiency Video Coding (HEVC) and Versatile Video Coding (VVC), face inaccuracies in prediction when reference blocks extend beyond picture boundaries, leading to padded values that do not reflect real pixel data, resulting in less accurate video reconstruction and increased computational load.

Innovation Solution

The implementation of an implicit masked blending mode that uses weighted prediction factors, allowing for a more accurate reconstruction based on real pixel data and reducing computational complexity by signaling weighted prediction factors in the bitstream.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If reference blocks are used for prediction when they extend beyond picture boundaries, then prediction coverage is improved, but prediction accuracy deteriorates due to padded values

Engineering Contradiction:

Improveprediction coverage areaVSAvoidprediction accuracy

Core Design Contradiction:

Area of stationary objectVSMeasurement precision

Solution Approach 1:

The current block is divided into multiple sections, with each section predicted using different reference blocks. This segmentation allows the encoder to select and combine reference blocks strategically, using only the valid (non-padded) portions for prediction, thereby maintaining both coverage and accuracy.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the current block are assigned different prediction qualities based on the validity of reference data. Regions with valid reference block data use those references for prediction, while regions that would require padded values use alternative prediction methods or are weighted differently, ensuring local prediction accuracy is maintained.

Inventive Principle:

Principle #3Local quality

2Measurement precision

If implicit masked blending mode is used to handle out-of-boundary reference blocks, then prediction accuracy is improved, but computational complexity increases

Engineering Contradiction:

Improveprediction accuracyVSAvoiddecoder computational complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The weighted prediction factors are pre-calculated and signaled in the bitstream during encoding. This preliminary action transfers the computational burden from the decoder to the encoder, where the factors can be computed once and reused, significantly reducing decoder complexity while maintaining the accuracy benefits of weighted blending.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The invention introduces weighted prediction factors as new parameters that modify the traditional blending operation. By changing the blending from uniform to weighted based on these factors, the system achieves higher prediction accuracy for out-of-boundary references while the factors themselves are efficiently signaled and applied with minimal computational overhead at the decoder.

Inventive Principle:

Principle #35Parameter changes

3Measurement precision

If weighted prediction factors are signaled in the bitstream, then coding accuracy is improved, but bit rate increases

Engineering Contradiction:

Improvecoding accuracyVSAvoidbit rate

Core Design Contradiction:

Measurement precisionVSQuantity of substance

Solution Approach 1:

The weighted prediction factors are not signaled for all blocks, but only selectively applied where beneficial. The encoder determines on a block-by-block basis whether the improvement in prediction accuracy justifies the additional bits, applying the weighted mode only when reference blocks are out-of-boundary or when quality improvement is significant, thus balancing accuracy gains with bit rate overhead.

Inventive Principle:

Principle #16Partial or excessive action

4Area of stationary object

If padding is applied to out-of-boundary reference blocks, then prediction coverage is maintained, but video quality deteriorates due to artificial pixel values

Engineering Contradiction:

Improveprediction coverageVSAvoidvideo quality degradation

Core Design Contradiction:

Area of stationary objectVSObject-affected harmful factors

Solution Approach 1:

The invention converts the harmful effect of padded reference values into a benefit by using the out-of-boundary condition as a trigger for alternative prediction strategies. When reference blocks extend beyond picture boundaries, the system activates weighted prediction modes that either use only valid reference portions or apply alternative reference selection, thereby transforming the quality-degrading padding issue into an opportunity for improved prediction accuracy.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Data Source

PatentUS20250024055A1Implicit masked blending mode improvement combined with weighted prediction

Publication Date: 2025.01.16 TENCENT AMERICA LLC

AI summary

The various implementations described herein include methods and systems for encoding and decoding video. For example, a computing system receives a video bitstream that includes a current block and a syntax element. The current block is encoded using information from a set of reference blocks. The system determines, based on the syntax element, whether the current block is encoded in a compound weighted prediction (CWP) mode. The system decodes the current block using a set of weighted prediction factors when the current block is encoded in the CWP mode. When the current block is not encoded in the CWP mode, the system decodes the current block using an implicit masked blending mode based on a weighted average of reference values associated with the set of reference blocks.