Entropy Encoder CABAC Binarized Symbol Constraint

Solution Overview

Problem

Existing video data encoding and decoding systems face challenges in efficiently compressing and decompressing image data, particularly in achieving optimal compression ratios and ensuring independent decodability of image sub-sections.

Innovation Solution

The proposed solution involves an image data encoding apparatus that uses a context adaptive binary arithmetic coding (CABAC) system or a bypass encoding system to encode image data. The apparatus generates an output data stream subject to a constraint that limits the number of binarized symbols per output data unit, and provides padding data to meet this constraint, ensuring that each slice and tile is independently decodable.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If CABAC or bypass encoding systems are used to compress image data, then compression efficiency is improved, but the number of binarized symbols per output data unit increases, violating the upper limit constraint

Engineering Contradiction:

Improvecompression efficiencyVSAvoidnumber of binarized symbols

Core Design Contradiction:

ProductivityVSQuantity of substance

Solution Approach 1:

The picture is divided into independently decodable units (slices and tiles) that can be processed separately. The entropy encoder applies the binarized symbol constraint to each slice and tile individually, allowing flexible control over the number of symbols in each segment while maintaining overall compression efficiency through parallel processing

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The encoder dynamically adjusts encoding parameters for different output data units based on their specific requirements. By modifying the constraint application strategy - applying it per-slice and per-tile rather than uniformly - the system optimizes compression efficiency while ensuring compliance with the upper limit on binarized symbols

Inventive Principle:

Principle #35Parameter changes

2Reliability

If independent decodability of slices and tiles is ensured, then reliability of decoding is improved, but device complexity increases due to additional constraint application requirements

Engineering Contradiction:

Improveindependent decodabilityVSAvoidconstraint application complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The picture is divided into independently decodable units (slices and tiles) that can be processed separately. The entropy encoder applies the binarized symbol constraint to each slice and tile individually, allowing flexible control over the number of symbols in each segment while maintaining overall compression efficiency through parallel processing

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The entropy encoder is designed to handle multiple types of output data units (slices and tiles) using a unified constraint application mechanism. This multi-functional approach ensures consistent enforcement of the binarized symbol limit across different picture regions while maintaining independent decodability without requiring separate complex handling for each unit type

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Manufacturing precision

If padding data is added to meet the binarized symbol constraint, then compliance with encoding profiles is improved, but the size of output data units increases

Engineering Contradiction:

Improveconstraint complianceVSAvoidoutput data unit size

Core Design Contradiction:

Manufacturing precisionVSQuantity of substance

Solution Approach 1:

Padding data is applied locally to specific output data units only when necessary to meet the binarized symbol constraint. Rather than uniformly increasing all output unit sizes, the system selectively adds padding to slices and tiles that would otherwise violate the upper limit, thereby ensuring constraint compliance while minimizing overall data size increase

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The encoder dynamically adjusts encoding parameters for different output data units based on their specific requirements. By modifying the constraint application strategy - applying it per-slice and per-tile rather than uniformly - the system optimizes compression efficiency while ensuring compliance with the upper limit on binarized symbols

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS20250119545A1Image data encoding and decoding

Publication Date: 2025.04.10 SONY GROUP CORP

AI summary

Image data encoding apparatus comprises an entropy encoder for selectively encoding data items representing image data to be encoded by a first, context adaptive binary arithmetic coding (CABAC), encoding system or by a second, bypass, encoding system, so as to generate encoded binarized symbols; the image data representing one or more pictures of a picture sequence, each picture comprising two or more output data units representing respective sub-sections of the picture, each sub-section being decodable and reconstructable independently of other sub-sections in that picture and picture sequence; the entropy encoder being configured to generate an output data stream subject to a constraint defining an upper limit to the number of binarized symbols that may be expressed by any individual output data unit relative to the size in bytes of that output data unit, in which the entropy encoder is configured to apply the constraint to each output data unit, and to provide padding data, for each output data unit which does not meet the constraint, so as to increase the size in bytes of that output data unit in order to meet the constraint.