HaarFeature.h

#ifndef HAAR_FEATURE_HEADER
#define HAAR_FEATURE_HEADER

#include "EstimatedGaussianDistribution.h"
#include "IntegralImage.h"
#include "Feature.h"

#define HAAR_FEATURE_MAX_NUM_AREAS 4

class HaarFeature {
public:
    HaarFeature(const Size &patchSize);
    virtual ~HaarFeature();

    // Get the initial distribution of the feature.
    void GetInitialDistribution(EstimatedGaussianDistribution<1> *distribution) const;

    bool Extract(const IntegralImage *intImage, const Rect &roi, Feature *feature);

    void Reset(const Size &patchSize);

    float GetResponse() { return response; }

    int GetNumAreas() { return numAreas; }

    int *GetWeights() { return weights; }

private:
    int type;
    int numAreas;
    int *weights;
    float initMean;
    float initSigma;

    // Generate a random Haar feature extractor.
    void GenerateRandomFeature(const Size &imageSize);
    
    // areas within the patch to compute the feature.
    Rect *areas;
    
    // size of patch used in training.
    Size initSize;
    
    // current size under investigation.
    Size curSize;

    // scale factor in vertical direction.
    float scaledHeight;

    // scale factor in horizontal direction.
    float scaledWidth;

    // areas after scaling.
    Rect *scaledAreas;

    // weights after scaling.
    float *scaledWeights;

    // The result feature from last extraction.
    float response;

    // A CDF for five types.
    static const float cdf[5];

    // Minimum size.
    static const Size minimumSize;
    static const int minimumArea;
};

#endif