Object Detection Using Rotating Haar Feature Database

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Solution Overview

Problem

Existing object detection algorithms, such as the Viola-Jones algorithm, require multiple Haar-feature databases for different orientations, leading to increased computational time and complexity when detecting objects in images with varying orientations.

Innovation Solution

The method involves capturing images in sampling windows and using a classifier with rotating sub-classifiers to detect objects in multiple orientations using a single Haar-Feature Database (HFDB), reducing the need for multiple orientations and halving the detection time by rotating the classifier and image.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If multiple Haar-feature databases are used for different orientations, then object detection accuracy for multiple orientations is improved, but computational time and algorithm complexity increase

Engineering Contradiction:
Improveobject detection accuracyVSAvoiddetection time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent makes a single Haar-feature database serve multiple orientations by rotating the database at predetermined angles (0°, 45°, 90°, 135°) to detect objects in different orientations. This eliminates the need for separate Haar-feature databases for each orientation, reducing computational overhead while maintaining detection accuracy across multiple orientations.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent dynamically rotates the Haar-feature database by predetermined angles during the detection process to adapt to objects in different orientations. Instead of using static, orientation-specific databases, the system dynamically adjusts the database orientation to match the object's orientation, improving efficiency while maintaining accuracy.

Inventive Principle:
Principle #15Dynamics

2Measurement precision

If multiple Haar-feature databases are used for different orientations, then object detection accuracy for multiple orientations is improved, but device complexity increases

Engineering Contradiction:
Improveobject detection accuracyVSAvoidalgorithm complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent makes a single Haar-feature database serve multiple orientations by rotating the database at predetermined angles (0°, 45°, 90°, 135°) to detect objects in different orientations. This eliminates the need for separate Haar-feature databases for each orientation, reducing computational overhead while maintaining detection accuracy across multiple orientations.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Loss of time

If a single Haar-feature database is used with rotation, then detection time is reduced, but the ability to detect objects in all orientations may be compromised

Engineering Contradiction:
Improvedetection timeVSAvoidobject detection accuracy
Core Design Contradiction:
Loss of timeVSMeasurement precision

Solution Approach 1:

The patent dynamically rotates the Haar-feature database by predetermined angles during the detection process to adapt to objects in different orientations. Instead of using static, orientation-specific databases, the system dynamically adjusts the database orientation to match the object's orientation, improving efficiency while maintaining accuracy.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent applies periodic rotation of the Haar-feature database at predetermined angles (0°, 45°, 90°, 135°) to cover all major object orientations. This periodic angular sampling ensures comprehensive orientation coverage while maintaining efficient detection speed, balancing accuracy and performance.

Inventive Principle:
Principle #19Periodic action

Data Source

PatentUS9020188B2Method for object detection and apparatus using the same
Publication Date: 2015.04.28 ASUSTEK COMPUTER INC
  • US9020188B2 patent drawing
  • US9020188B2 patent drawing
  • US9020188B2 patent drawing

AI summary

A method for object detection and an apparatus using the same are provided, and the method includes: An image is captured, in which the image includes a plurality of sampling-windows. A first-stage sub-classifier of a classifier is used to detect whether the sampling-windows contain an object therein. The classifier is rotated at least one time by a predetermined rotation angle and the first-stage sub-classifier of the classifier is used to detect whether the sampling-windows contain the object after each rotating, wherein when the object is detected within the sampling-windows, keep detecting whether the sampling-windows contain the object therein sequentially by a second-stage sub-classifier to an Nth stage sub-classifier of the classifier with the same orientation. The image is rotated at least one time by a predetermined image angle and the above-mentioned operations of detecting the object is performed after each rotating. The sampling-windows containing the object are output.