Variable-Size Entropy Coding for Better Compression of Mixed Symbols

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Solution Overview

Problem

Existing entropy-based data compression methods are inadequate for handling symbols of variable sizes, as they assume all symbols have the same size, leading to suboptimal compression and decompression efficiency.

Innovation Solution

A method and system that sample data to establish relative frequencies of symbols of different sizes, generate variable-length codewords based on these frequencies and sizes, and compress data using these codewords, including metadata for decompression, allowing for efficient compression and decompression of symbols with varying sizes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If existing entropy-based data compression methods are used, then data compression is achieved, but compression efficiency is suboptimal when handling symbols of variable sizes

Engineering Contradiction:
Improvecompression efficiencyVSAvoidhandling of variable-sized symbols
Core Design Contradiction:
ProductivityVSAdaptability or versatility

Solution Approach 1:

The patent applies dynamics by making the symbol size parameter variable rather than fixed. The compression system dynamically adapts to handle symbols of different sizes (e.g., 8-bit, 16-bit, 32-bit, 64-bit) by adjusting the encoding process based on the actual symbol size in the input data, thereby improving compression efficiency for variable-sized symbols while maintaining adaptability.

Inventive Principle:
Principle #15Dynamics

2Device complexity

If fixed-size symbol assumption is made, then simpler encoding process is achieved, but decompression accuracy deteriorates for variable-sized symbols

Engineering Contradiction:
Improveencoding process complexityVSAvoiddecompression accuracy
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The patent applies preliminary action by embedding size metadata in the compressed data structure before decompression occurs. The compressed representation includes information about the original symbol size, which is used during decompression to accurately reconstruct variable-sized symbols. This preliminary inclusion of size information ensures decompression accuracy without significantly increasing encoding process complexity.

Inventive Principle:
Principle #10Preliminary action

3Productivity

If variable-length codewords are generated based on symbol frequencies, then compression ratio is improved, but decompression complexity increases

Engineering Contradiction:
Improvecompression ratioVSAvoiddecompression complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent applies the intermediary principle by introducing a codebook or lookup table as an intermediate structure that maps variable-length codewords back to their corresponding symbols. During decompression, the stored size metadata acts as an intermediary that guides the reconstruction process, allowing the system to achieve high compression ratios through variable-length encoding while managing decompression complexity through structured lookup mechanisms.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentUS10862507B2Variable-sized symbol entropy-based data compression
Publication Date: 2020.12.08 ZEROPOINT TECH AB
  • US10862507B2 patent drawing
  • US10862507B2 patent drawing
  • US10862507B2 patent drawing

AI summary

Methods, devices and systems for data compression and decompression are disclosed. A collection of data is obtained. The collection of data is sampled to establish, for a plurality of different symbol sizes, relative frequencies of symbols of the respective sizes in the collection of data. A code is generated to contain variable-length codewords by entropy encoding sampled symbols in the collection of data based on a metric which reflects the relative frequencies of the sampled symbols as well as their sizes. Symbols in the collection of data are compressed into compressed representations using the generated code, wherein the compressed representation of a symbol comprises a codeword which represents the symbol as well as metadata for decompressing the compressed representation.