Sparse Overcomplete Feature Dictionaries for Image Classification

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Solution Overview

Problem

Current machine vision technologies face challenges in effectively classifying and clustering objects in images, especially those with materials common across various object categories, due to reliance on distinctive local features and high computational requirements, which are not efficiently addressed by conventional approaches.

Innovation Solution

The use of sparse overcomplete feature dictionaries learned through non-convex basis pursuit algorithms allows for efficient classification and clustering of image data by projecting original data into a higher order space, enabling fewer terms to represent the data and reducing computational complexity, applicable to remote sensing, social media, and other image data types.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional color-texture analysis methods are used for object classification, then objects with distinctive local features can be identified, but objects with common materials across multiple categories cannot be properly classified

Engineering Contradiction:
Improveobject classification accuracyVSAvoidability to handle diverse object materials
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The patent transforms image data from the original spatial domain into a higher-order sparse representation space using learned overcomplete dictionaries. This dimensional transformation enables the system to capture material characteristics that are not apparent in conventional color-texture analyses, allowing proper classification of objects with common materials across different categories.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The invention changes the parameter representation by learning adaptive dictionaries that transform image patches into sparse coefficient vectors. These learned parameters capture essential material properties in a compressed form, enabling discrimination between objects based on material composition rather than just visual appearance, thus improving classification of objects with prevalent materials.

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If large scale neural network models with billions of parameters are used for image processing, then human vision performance can be approached, but computational requirements become prohibitively high

Engineering Contradiction:
Improvevision performance accuracyVSAvoidcomputational energy consumption
Core Design Contradiction:
Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The patent extracts only the essential features needed for image classification by representing images in sparse code form. Instead of processing all pixels and features through large neural networks, the system extracts dominant components through sparse representation, retaining only the most informative elements for classification while discarding redundant information, thus dramatically reducing computational energy consumption.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention discards redundant visual information by using sparse representations where most coefficients are zero or near-zero. Only the essential non-zero coefficients are retained and processed further, enabling the system to achieve high classification accuracy with minimal computational resources. The sparse coding framework naturally performs this discarding of unnecessary information while preserving essential features.

Inventive Principle:
Principle #34Discarding and recovering

3Speed

If full scale hierarchical models of visual cortex are implemented, then real-time processing of high definition video can be achieved, but the system requires petaflop scale computing resources

Engineering Contradiction:
Improvereal-time video processing speedVSAvoidcomputational infrastructure complexity
Core Design Contradiction:
SpeedVSDevice complexity

Solution Approach 1:

The patent segments the image processing task into two distinct stages: (1) sparse coding stage that transforms image patches into compact representations using learned dictionaries, and (2) classification stage that processes the compressed sparse codes. This segmentation enables real-time processing by performing the computationally intensive transformation only once during sparse coding, then efficiently classifying multiple frames using the compressed representations, thereby reducing overall computational infrastructure requirements.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention performs preliminary sparse coding transformation on image data before classification. By pre-processing images into sparse representations that capture essential features in a compressed form, the system prepares the data in advance for efficient classification. This preliminary action reduces the computational burden of subsequent processing steps, enabling real-time video processing without requiring petaflop-scale infrastructure for each classification operation.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentUS9152881B2Image fusion using sparse overcomplete feature dictionaries
Publication Date: 2015.10.06 TRIAD NATIONAL SECURITY LLC
  • US9152881B2 patent drawing
  • US9152881B2 patent drawing
  • US9152881B2 patent drawing

AI summary

Approaches for deciding what individuals in a population of visual system “neurons” are looking for using sparse overcomplete feature dictionaries are provided. A sparse overcomplete feature dictionary may be learned for an image dataset and a local sparse representation of the image dataset may be built using the learned feature dictionary. A local maximum pooling operation may be applied on the local sparse representation to produce a translation-tolerant representation of the image dataset. An object may then be classified and/or clustered within the translation-tolerant representation of the image dataset using a supervised classification algorithm and/or an unsupervised clustering algorithm.