RGIFeature.h

#ifndef RGIFEATURE_HEADER
#define RGIFEATURE_HEADER

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

#define NUM_RGI_BINS 9

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

    void GetInitialDistribution(EstimatedGaussianDistribution<NUM_RGI_BINS> *distribution) const;
    bool Extract(const IntegralImage *intImage, const Rect &roi, Feature *feature);

    void Reset(const Size &patchSize);

private:

    Rect patch, scaledPatch;

    // size of initial patch.
    Size initSize;

    // current size under investigation.
    Size curSize;

    // scale factor in vertical direction.
    float scaledHeight;

    // scale factor in horizontal direction.
    float scaledWidth;

    void GeneratreRandomFeature(const Size &imgSize);

    inline void NormalizeHistogram(float *histogram, int N) const {
        float sum = 0.0f;
        for (int i = 0; i < N; i++) {
            
            // Some tests.
            assert(histogram[i] >= 0.0f);

            sum += histogram[i];
        }
        float invSum = 1.0f / sum;
        for (int i = 0; i < N; i++) {
            histogram[i] *= invSum;
        }
    }

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

    const static float initMean[NUM_RGI_BINS];
    const static float initSigma[NUM_RGI_BINS];
};

#endif