Arithmetic Range Encoding for Lower-Bitrate Video Compression

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Solution Overview

Problem

Current video data compression and decompression systems face inefficiencies in entropy encoding, particularly with existing techniques like CABAC, which do not fully optimize bit rate and image quality, especially at higher bit depths and low quantization parameters.

Innovation Solution

The implementation of advanced entropy encoding techniques, such as modified CABAC processes and fixed-bit encoding schemes, to improve compression efficiency by adapting context modeling and bit allocation, allowing for higher bit depth operations without significant loss in resolution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If CABAC entropy encoding is used, then compression efficiency is improved, but complexity of the encoding process increases

Engineering Contradiction:
Improvecompression efficiencyVSAvoidencoding process complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent divides the encoding process into distinct stages: context modeling, binary arithmetic coding, and range normalization. By segmenting the complex CABAC process into manageable components, the patent reduces implementation complexity while preserving compression efficiency. Each stage can be independently optimized and implemented.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements dynamic context modeling where context probabilities are updated adaptively based on previously encoded data. This dynamic adjustment allows the encoder to optimize for specific data patterns and characteristics, improving compression efficiency without requiring a completely complex static structure for all possible scenarios.

Inventive Principle:
Principle #15Dynamics

2Manufacturing precision

If higher bit depth operations are performed, then image quality is improved, but bit rate increases

Engineering Contradiction:
Improveimage qualityVSAvoidbit rate
Core Design Contradiction:
Manufacturing precisionVSQuantity of substance

Solution Approach 1:

The patent employs parameter optimization techniques that adjust encoding parameters dynamically based on the input data characteristics. By changing parameters such as context table sizes, probability update frequencies, and arithmetic coding precision, the patent achieves high image quality at lower bit rates by optimizing the balance between precision and data representation efficiency.

Inventive Principle:
Principle #35Parameter changes

3Quantity of substance

If context adaptive binary arithmetic coding is used, then data size is reduced, but computational complexity increases

Engineering Contradiction:
Improvedata sizeVSAvoidcomputational complexity
Core Design Contradiction:
Quantity of substanceVSDevice complexity

Solution Approach 1:

The patent performs preliminary context modeling and probability estimation before the actual arithmetic coding process. By pre-computing context probabilities and preparing encoding tables in advance, the patent reduces the computational burden during the actual encoding phase, thereby reducing real-time computational complexity while maintaining data size reduction benefits.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements a hybrid approach where full precision arithmetic coding is applied only when necessary, while using simplified coding methods for data patterns that can be efficiently encoded with lower precision. This partial application of complex methods reduces overall computational complexity while maintaining effective data size reduction for the most beneficial cases.

Inventive Principle:
Principle #16Partial or excessive action

Data Source

PatentUS11671599B2Data encoding and decoding
Publication Date: 2023.06.06 SONY GROUP CORP
  • US11671599B2 patent drawing
  • US11671599B2 patent drawing
  • US11671599B2 patent drawing

AI summary

A method of data encoding input data values of a data set for encoding includes selecting one of a plurality of complementary sub-ranges of a set of code values according to the value of a current input data value, the set of code values being defined by a range variable, assigning the current input data value to a code value within the selected sub-range, modifying the set of code values in dependence upon the assigned code value and the size of the selected sub-range, detecting whether the range variable defining the set of code values is less than a predetermined minimum size and if so, successively increasing the range variable so as to increase the size of the set of code values until it has at least the predetermined minimum size and outputting an encoded data bit in response to each such size-increasing operation, and after encoding a group of input data values, setting the range variable to a value selected from a predetermined subset of available range variable values, each value in the subset having at least one least significant bit equal to zero.