org.openimaj.image.objectdetection.haar

Class HaarFeatureClassifier

java.lang.Object

org.openimaj.image.objectdetection.haar.HaarFeatureClassifier

All Implemented Interfaces:

Classifier

@Reference(type=Inproceedings,
           author={"Viola, P.","Jones, M."},
           title="Rapid object detection using a boosted cascade of simple features",
           year="2001",
           booktitle="Computer Vision and Pattern Recognition, 2001. CVPR 2001. Proceedings of the 2001 IEEE Computer Society Conference on",
           pages={" I","511 "," I","518 vol.1"},
           number="",
           volume="1",
           customData={"keywords"," AdaBoost; background regions; boosted simple feature cascade; classifiers; face detection; image processing; image representation; integral image; machine learning; object specific focus-of-attention mechanism; rapid object detection; real-time applications; statistical guarantees; visual object detection; feature extraction; image classification; image representation; learning (artificial intelligence); object detection;","doi","10.1109/CVPR.2001.990517","ISSN","1063-6919 "})
public class HaarFeatureClassifier
extends Object
implements Classifier

A classifier based on a Haar-like feature. The classifier forms a binary tree (or stump) and has left and right nodes to apply depending on the outcome of feature evaluation. If this classifier is a stump, then its left and right nodes will be ValueClassifiers. If it is a tree, then the left and/or right nodes will be HaarFeatureClassifiers.

Author:

Jonathon Hare (jsh2@ecs.soton.ac.uk)

Constructor Summary

Constructors

Constructor and Description
HaarFeatureClassifier(HaarFeature feature, float threshold, Classifier left, Classifier right) Construct with the given feature, threshold and left/right nodes.

Method Summary

Modifier and Type	Method and Description
float	classify(SummedSqTiltAreaTable sat, float wvNorm, int x, int y) Get the classification score for the window at (x, y) with the size defined by scale.
void	updateCaches(StageTreeClassifier cascade) Update the caches for a given scale (given by the cachedScale of the StageTreeClassifier).

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

HaarFeatureClassifier

public HaarFeatureClassifier(HaarFeature feature,
                             float threshold,
                             Classifier left,
                             Classifier right)

Construct with the given feature, threshold and left/right nodes.

Parameters:

feature - the feature on which the classifier is based.

threshold - the threshold for the classifier.

left - the classifier to invoke if the feature response is less than the threshold

right - the classifier to invoke if the feature response is greater than or equal to the threshold

Method Detail

classify

public float classify(SummedSqTiltAreaTable sat,
                      float wvNorm,
                      int x,
                      int y)

Description copied from interface: Classifier

Get the classification score for the window at (x, y) with the size defined by scale.

Specified by:

classify in interface Classifier

Parameters:

sat - the summed area tables (integral images)

wvNorm - the normalisation based on the current window variance

x - the x-ordinate of the top-left of the window being tested

y - the y-ordinate of the top-left of the window being tested

Returns:

the classification score

updateCaches

public void updateCaches(StageTreeClassifier cascade)

Description copied from interface: Classifier

Update the caches for a given scale (given by the cachedScale of the StageTreeClassifier).

Specified by:

updateCaches in interface Classifier

Parameters:

cascade - the tree of stages