Integer Sequence Encoding via Bijective Transformation and Golomb-Rice

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Solution Overview

Problem

Existing techniques for encoding integer sequences, such as those following distributions other than Laplacian, face challenges with memory size and calculation processing due to large mapping tables or reduced compression efficiency under low bit rates.

Innovation Solution

An encoder and decoder system that uses algebraically-representable bijective transformations to transform integer sets into single or multiple values, allowing for Golomb-Rice encoding, which reduces bit length and memory/calculations by associating codes with transformed integers.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a mapping table is used to encode integer sequences with distributions other than Laplacian, then compression performance is improved, but memory size increases

Engineering Contradiction:
Improvecompression performanceVSAvoidmemory size
Core Design Contradiction:
ProductivityVSWeight of stationary object

Solution Approach 1:

The patent extracts only the essential transformation rules from the complete mapping table approach. Instead of storing and searching entire mapping tables, the invention extracts algebraic transformation formulas (e.g., y = (x1 + x2) / 2, y = (x1 + x2 + 1) / 2) that can generate the mapping relationships on-the-fly, eliminating the need for large pre-computed tables while maintaining compression performance.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent transforms the static mapping table approach into a dynamic algebraic transformation approach. The encoding relationships are no longer fixed in a pre-computed table but are generated dynamically through algebraic formulas during the encoding process, allowing the system to adapt to different input sequences without requiring large memory storage.

Inventive Principle:
Principle #15Dynamics

2Productivity

If a mapping table is used to encode integer sequences with distributions other than Laplacian, then compression performance is improved, but calculation processing increases

Engineering Contradiction:
Improvecompression performanceVSAvoidcalculation processing
Core Design Contradiction:
ProductivityVSLoss of time

Solution Approach 1:

The patent replaces the mechanical system of table lookup and search with an algebraic calculation system. Instead of searching through mapping tables to find appropriate transformations, the invention uses direct algebraic formulas that compute the transformed values through simple arithmetic operations, significantly reducing calculation processing time.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent performs preliminary analysis to identify the distribution characteristics of the integer sequence and selects the appropriate algebraic transformation formula in advance. This preliminary action allows the system to use the most efficient transformation for each sequence type, avoiding the need for time-consuming searches during the actual encoding process.

Inventive Principle:
Principle #10Preliminary action

3Device complexity

If Golomb-Rice code is used for integer sequences with distributions other than Laplacian, then encoding simplicity is maintained, but compression efficiency deteriorates

Engineering Contradiction:
Improveencoding simplicityVSAvoidcompression efficiency
Core Design Contradiction:
Device complexityVSProductivity

Solution Approach 1:

The patent changes the parameters of the encoding approach by introducing algebraic transformations that modify the integer sequences before applying Golomb-Rice coding. By transforming the input sequences through algebraic operations (such as averaging pairs of integers or applying linear transformations), the patent adapts the data distribution to better match the assumptions of Golomb-Rice coding, thereby improving compression efficiency while maintaining the simplicity of the overall encoding process.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3644515B1Encoding device, decoding device, encoding method, decoding method and program
Publication Date: 2022.08.24 NIPPON TELEGRAPH & TELEPHONE CORP
  • EP3644515B1 patent drawingFigure 1
  • EP3644515B1 patent drawingFigure 2~3
  • EP3644515B1 patent drawingFigure 4~5

AI summary

A sequence of integer values is encoded and decoded with a number of bits of a decimal value substantially assigned per sample or/and with a smaller memory amount or calculation processing amount than in the prior art. The encoder receives the sequence of integer values as input and outputs an integer code corresponding to the sequence of integer values. An integer transformer (11) obtains one integer value (transformed integer) through algebraically-representable bijective transformation for each of a plurality of sets of integer values included in the inputted sequence of integer values. An integer encoder (12) encodes the transformed integer to thereby obtain an integer code.