Deformable Expression Detection Using Gradient Sign Coding

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Solution Overview

Problem

Current electronic devices lack efficient methods for detecting deformable expressions, such as facial emotions or gestures, which limits their functionality in applications like human-machine interfaces and image capture systems.

Innovation Solution

A method and apparatus for deformable expression detection using a combination of directional gradient components, where signs of these components are coded into values to classify expressions like smiling, blinking, or anger, employing machine learning algorithms like SVM, KNN, and boosting algorithms, with feedback mechanisms to adjust classification errors and decision thresholds.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If traditional expression detection methods are used, then detection accuracy may be maintained, but computational complexity increases and processing efficiency decreases

Engineering Contradiction:
Improveprocessing efficiencyVSAvoidcomputational complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent extracts only the essential sign information from gradient components rather than processing complete gradient magnitude and direction data. By taking out only the critical sign features (positive/negative directions) and discarding redundant magnitude information, the system achieves simpler computation while maintaining expression detection accuracy

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent transforms the continuous gradient information into discrete sign-based coded values (e.g., 0, 1, 2, 3 representing different direction combinations). This parameter transformation from continuous to discrete space reduces computational burden while preserving the essential directional information needed for expression detection

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If comprehensive image processing is performed, then expression detection accuracy improves, but processing time increases

Engineering Contradiction:
Improveexpression detection accuracyVSAvoidprocessing time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent performs preliminary preprocessing operations (alignment, cropping, scaling, histogram equalization) before the main expression detection. By preparing the image in advance with these standardized operations, the subsequent gradient-based detection can proceed efficiently without needing to perform complex real-time adjustments during detection

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent extracts only the sign information from gradient components rather than processing complete gradient magnitude and direction data. By taking out only the critical sign features (positive/negative directions) and discarding redundant magnitude information, the system achieves simpler computation while maintaining expression detection accuracy

Inventive Principle:
Principle #2Taking out (Extraction)

3Device complexity

If simple coding methods are used, then computational complexity is reduced, but information loss increases

Engineering Contradiction:
Improvecomputational complexityVSAvoidgradient magnitude information
Core Design Contradiction:
Device complexityVSLoss of information

Solution Approach 1:

The patent converts the potential harm of information loss into a benefit by demonstrating that gradient magnitude information is actually redundant for expression detection. The sign information alone suffices to capture the essential directional patterns of facial expressions, turning what could be seen as an information deficiency into a computational advantage

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Data Source

PatentUS9141851B2Deformable expression detector
Publication Date: 2015.09.22 QUALCOMM INC
  • US9141851B2 patent drawing
  • US9141851B2 patent drawing
  • US9141851B2 patent drawing

AI summary

A method for deformable expression detection is disclosed. For each pixel in a preprocessed image, a sign of a first directional gradient component and a sign of a second directional gradient component are combined to produce a combined sign. Each combined sign is coded into a coded value. An expression in an input image is detected based on the coded values.