Neural Network Image Compression via Learned Coefficient Patch Indices

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Solution Overview

Problem

Traditional lossy image compression techniques struggle to balance visual quality and file size reduction, especially in motion video coding, where they often sacrifice important image details.

Innovation Solution

The use of neural networks for encoding and decoding images, where an encoder transforms images into coefficients, encodes them as integer patch indices into a set coding table, and a decoder reconstructs the images using jointly trained weights, with optional entropy coding to further compress the data.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If traditional lossy image compression techniques (domain transform, quantization, entropy coding) are used, then file size is reduced, but visual quality and important image details are sacrificed

Engineering Contradiction:
Improvefile sizeVSAvoidvisual quality
Core Design Contradiction:
Quantity of substanceVSManufacturing precision

Solution Approach 1:

The patent replaces traditional mechanical compression algorithms (DCT, quantization matrices) with a neural network system that learns optimal compression through training. The encoder neural network and decoder neural network are trained jointly to minimize reconstruction error while achieving compression, substituting fixed mathematical transforms with adaptive learned transformations that preserve visual quality better than traditional methods

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

Solution Approach 2:

The patent changes the fundamental parameters of image compression by using learned transforms instead of fixed DCT bases, and by using learned quantization strategies instead of fixed quantization matrices. The neural networks learn optimal parameter representations that adapt to different image content, allowing better preservation of important visual information while achieving compression

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If neural networks are trained to predict image information, then visual quality is improved, but computational complexity and training requirements increase

Engineering Contradiction:
Improvevisual qualityVSAvoidcomputational complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent performs preliminary training of the neural network models offline using large datasets before deployment. The encoder and decoder networks are pre-trained jointly to learn optimal compression representations. This preliminary action transfers the computational burden to the training phase, allowing the actual compression and decompression operations to be more efficient during runtime

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent uses a codebook that stores pre-computed code vectors representing common image patterns. Instead of performing complex neural network operations for every compression task, the system copies relevant code vectors from the codebook that match the input image blocks, reducing computational complexity during actual compression while maintaining quality through the learned representations

Inventive Principle:
Principle #26Copying

Data Source

PatentUS11496769B2Neural network based image set compression
Publication Date: 2022.11.08 APPLE INC
  • US11496769B2 patent drawing
  • US11496769B2 patent drawing
  • US11496769B2 patent drawing

AI summary

Techniques for coding sets of images with neural networks include transforming a first image of a set of images into coefficients with an encoder neural network, encoding a group of the coefficients as an integer patch index into coding table of table entries each having vectors of coefficients, and storing a collection of patch indices as a first coded image. The encoder neural network may be configured with encoder weights determined by jointly with corresponding decoder weights of a decoder neural network on the set of images.