Video Coding Filter Coefficients Exploiting Symmetry

Solution Overview

Problem

Current block-based digital video coding techniques require transmitting all filter coefficients from an encoder to a decoder, which increases data volume and reduces compression efficiency due to the lack of efficient methods to convey symmetry information.

Innovation Solution

The proposed solution exploits horizontal and vertical symmetry in filter coefficients by predictingively encoding a second set of coefficients using a first set, where only the first set and difference values are transmitted, allowing the decoder to reconstruct the complete set of filter coefficients.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If all filter coefficients are transmitted from encoder to decoder, then the decoder can apply correct filtering to improve video quality, but the data volume increases and compression efficiency decreases

Engineering Contradiction:

Improvefiltering accuracyVSAvoiddata volume

Core Design Contradiction:

ReliabilityVSQuantity of substance

Solution Approach 1:

The patent extracts only the essential information needed for filtering by identifying and transmitting only the unique filter coefficients rather than all coefficients. By recognizing the symmetric structure of filter coefficients, the patent extracts only the necessary subset (e.g., coefficients in one quadrant) and omits redundant transmissions, thereby reducing data volume while preserving filtering accuracy.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

Instead of transmitting all filter coefficients directly from encoder to decoder, the patent inverts the approach by having the decoder reconstruct the complete set of filter coefficients from a reduced set using symmetry relationships. The decoder uses the transmitted unique coefficients to derive the remaining coefficients through mathematical symmetry operations, achieving the opposite flow of information reconstruction.

Inventive Principle:

Principle #13The other way round (Inversion)

2Reliability

If all filter coefficients are transmitted from encoder to decoder, then the complete filter information is available for accurate video block filtering, but the compression efficiency is reduced

Engineering Contradiction:

Improvefiltering accuracyVSAvoidcompression efficiency

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The patent extracts only the essential information needed for filtering by identifying and transmitting only the unique filter coefficients rather than all coefficients. By recognizing the symmetric structure of filter coefficients, the patent extracts only the necessary subset (e.g., coefficients in one quadrant) and omits redundant transmissions, thereby reducing data volume while preserving filtering accuracy.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent changes the representation parameters of filter coefficients by organizing them according to their symmetric properties. Instead of transmitting coefficients in their original sequential order, the patent reorganizes and transmits only the independent parameters that define the complete filter set through symmetry, improving compression efficiency while maintaining filtering accuracy.

Inventive Principle:

Principle #35Parameter changes

3Reliability

If symmetry information is not utilized in filter coefficient transmission, then all coefficients must be transmitted to ensure accurate decoding, but this increases the amount of data required

Engineering Contradiction:

Improvedecoding accuracyVSAvoiddata volume

Core Design Contradiction:

ReliabilityVSQuantity of substance

Solution Approach 1:

The patent applies asymmetry in the transmission strategy by treating different sets of filter coefficients differently based on their symmetric relationships. Instead of uniformly transmitting all coefficients, the patent identifies asymmetric unique coefficients that cannot be derived from others and transmits only those, while omitting symmetric redundant coefficients that can be reconstructed through symmetry operations.

Inventive Principle:

Principle #4Asymmetry

Solution Approach 2:

Instead of transmitting all filter coefficients directly from encoder to decoder, the patent inverts the approach by having the decoder reconstruct the complete set of filter coefficients from a reduced set using symmetry relationships. The decoder uses the transmitted unique coefficients to derive the remaining coefficients through mathematical symmetry operations, achieving the opposite flow of information reconstruction.

Inventive Principle:

Principle #13The other way round (Inversion)

Data Source

PatentUS8638852B2Video coding of filter coefficients based on horizontal and vertical symmetry

Publication Date: 2014.01.28 QUALCOMM INC

AI summary

This disclosure recognizes and exploits the fact that some of the filter coefficients defined at the encoder may possess symmetry relative to other filter coefficients. Accordingly, this disclosure describes techniques in which a first set of the filter coefficients are used to predictively encode a second set of the filter coefficients, thereby exploiting any symmetry between filter coefficients. Rather than communicate all of the filter coefficients to the decoding device, the encoding device may communicate the first set of filter coefficients and difference values associated with the second set of filter coefficients. Using this information, the decoder may be able to reconstruct all of the filter coefficients. In some cases, if exact symmetry is imposed, the need to send the difference values may be eliminated and the decoder may be able to derive the second set of filter coefficients from the first set of filter coefficients.