IntegralImage.h

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/*
 * This file is part of ALVAR, A Library for Virtual and Augmented Reality.
 *
 * Copyright 2007-2012 VTT Technical Research Centre of Finland
 *
 * Contact: VTT Augmented Reality Team <alvar.info@vtt.fi>
 *          <http://www.vtt.fi/multimedia/alvar.html>
 *
 * ALVAR is free software; you can redistribute it and/or modify it under the
 * terms of the GNU Lesser General Public License as published by the Free
 * Software Foundation; either version 2.1 of the License, or (at your option)
 * any later version.
 *
 * This library is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
 * for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with ALVAR; if not, see
 * <http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html>.
 */

#ifndef INTEGRAL_IMAGE_H
#define INTEGRAL_IMAGE_H

#include "Alvar.h"
#include <cxcore.h>
#include <cv.h>

namespace alvar {

class ALVAR_EXPORT IntIndex {
protected:
    int index;
    int step;
    int step_remainder;
    int estep;
    int next_step;
    int res;
    int steps;
    void update_next_step();
public:
    IntIndex(int _res, int _steps);
    int operator=(int v);
    int next();
    int get() const;
    int get_next_step() const;
    int end() const;
};


class ALVAR_EXPORT IntegralImage {
        IplImage *sum;
public:
        IntegralImage();
        ~IntegralImage();
        void Update(IplImage *gray);
    double GetSum(CvRect &rect, int *count=0);
        double GetAve(CvRect &rect);
    void GetSubimage(const CvRect &rect, IplImage *sub);
};

class ALVAR_EXPORT IntegralGradient {
protected:
        IplImage *normalx;
        IplImage *normaly;
        IntegralImage integx;
        IntegralImage integy;
        // Calculate point normals for 4-pixel intersection
        // as described in Donahue1992
        void CalculatePointNormals(IplImage *gray);
public:
        IntegralGradient();
        ~IntegralGradient();
        void Update(IplImage *gray);
        void GetGradient(CvRect &rect, double *dirx, double *diry, int *count=0);
        void GetAveGradient(CvRect &rect, double *dirx, double *diry);
};

} // namespace alvar

#endif