Frequency Domain Data Compression for Neural Network Memory

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Solution Overview

Problem

The existing convolution methods using Fourier transforms for image processing result in increased memory consumption due to the large amount of data generated during the convolution operation, particularly in neural networks with multiple layers, which can lead to processing inefficiencies, especially in embedded systems with limited memory capacity.

Innovation Solution

A data compression apparatus and method that calculates frequency domain coefficients using Fourier transforms, omits coefficients below a threshold, and generates feature maps using inverse Fourier transforms, reducing the data stored and processed, thereby compressing data efficiently and minimizing memory consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If convolution is performed using Fourier transform to achieve higher computation speed, then processing speed is improved, but memory consumption increases due to the large amount of frequency domain data generated

Engineering Contradiction:
Improveconvolution processing speedVSAvoidmemory consumption
Core Design Contradiction:
SpeedVSQuantity of substance

Solution Approach 1:

The patent extracts and stores only the significant frequency components (those with magnitude above a threshold) from the full frequency domain data. By separating and retaining only the essential coefficients needed for accurate convolution results, the system reduces memory consumption while preserving the computational advantages of Fourier transform-based convolution.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent applies different storage strategies to different frequency components based on their significance. Significant coefficients (above threshold) are stored in memory for accurate processing, while insignificant coefficients (below threshold) are discarded. This localized quality approach optimizes the balance between memory usage and computational accuracy.

Inventive Principle:
Principle #3Local quality

2Measurement precision

If all frequency domain coefficients are stored to maintain convolution accuracy, then processing accuracy is improved, but memory capacity requirements increase

Engineering Contradiction:
Improveconvolution result accuracyVSAvoidmemory capacity
Core Design Contradiction:
Measurement precisionVSQuantity of substance

Solution Approach 1:

The patent extracts only the necessary frequency components for accurate convolution by applying a magnitude threshold. This extraction process identifies and retains only those coefficients that contribute significantly to the convolution result, eliminating the need to store all coefficients and thereby reducing memory capacity requirements while maintaining accuracy.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent uses partial action by storing only a subset of frequency coefficients rather than all coefficients. By applying a threshold criterion, the system stores just enough data to achieve accurate convolution results without the excess of storing complete frequency domain data, optimizing the trade-off between accuracy and memory usage.

Inventive Principle:
Principle #16Partial or excessive action

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach effectively reduces memory consumption during convolution operations, allowing for faster processing and efficient use of memory resources, even in systems with limited capacity, without significantly affecting the accuracy of feature extraction in image recognition tasks.

Implementation Method 1

calculating, from the image data, a plurality of first coefficients corresponding to different frequencies using a Fourier transform

Methodology Applied
Scientific EffectFourier transform:

Implementation Method 2

generating a feature map indicating a result of applying the kernel data to the image data using the first frequency domain data, the second frequency domain data, and an inverse Fourier transform

Methodology Applied
Scientific EffectInverse Fourier transform:

Data Source

PatentUS10757446B2Data compression apparatus and data compression method
Publication Date: 2020.08.25 FUJITSU LTD
  • US10757446B2 patent drawing
  • US10757446B2 patent drawing
  • US10757446B2 patent drawing

AI summary

A processor calculates, from image data, a plurality of first coefficients corresponding to different frequencies using a Fourier transform and stores first frequency domain data, from which first coefficients whose magnitude is below a threshold have been excluded, in a memory. The processor also calculates, from kernel data, second coefficients of frequencies corresponding to the first coefficients indicated by the first frequency domain data using a Fourier transform and stores second frequency domain data in the memory. The processor uses the first frequency domain data, the second frequency domain data, and an inverse Fourier transform to generate a feature map indicating a result of applying the kernel data to the image data.