/*
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 *
 *  License Agreement
 *  For Open Source Computer Vision Library
 *  (3 - clause BSD License)
 *
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 *  are permitted provided that the following conditions are met :
 *
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 *  this list of conditions and the following disclaimer.
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 *  * Redistributions in binary form must reproduce the above copyright notice,
 *  this list of conditions and the following disclaimer in the documentation
 *  and / or other materials provided with the distribution.
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 *  may be used to endorse or promote products derived from this software
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 *  This software is provided by the copyright holders and contributors "as is" and
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 */

#include <opencv2/core.hpp>
#include <opencv2/core/utility.hpp>
#include <opencv2/highgui.hpp>
#include <opencv2/ximgproc.hpp>
#include "opencv2/ximgproc/paillou_filter.hpp"

using namespace cv;
using namespace cv::ximgproc;

#include <iostream>
using namespace std;

int aa = 100, ww = 10;

Ptr<Mat> img;
const char* window_name = "Gradient Modulus";

static void DisplayImage(Mat x,string s)
{
	vector<Mat> sx;
	split(x, sx);
	vector<double> minVal(3), maxVal(3);
	for (int i = 0; i < static_cast<int>(sx.size()); i++)
	{
		minMaxLoc(sx[i], &minVal[i], &maxVal[i]);
	}
	maxVal[0] = *max_element(maxVal.begin(), maxVal.end());
	minVal[0] = *min_element(minVal.begin(), minVal.end());
	Mat uc;
	x.convertTo(uc, CV_8U,255/(maxVal[0]-minVal[0]),-255*minVal[0]/(maxVal[0]-minVal[0]));
	imshow(s, uc);
}


/**
 * @function paillouFilter
 * @brief Trackbar callback
 */
static void PaillouFilter(int, void*)
{
    Mat dst;
    double a=aa/100.0,w=ww/100.0;
    Mat rx,ry;
    GradientPaillouX(*img.get(),rx,a,w);
    GradientPaillouY(*img.get(),ry,a,w);
    DisplayImage(rx, "Gx");
    DisplayImage(ry, "Gy");
    add(rx.mul(rx),ry.mul(ry),dst);
    sqrt(dst,dst);
    DisplayImage(dst, window_name );
}


int main(int argc, char* argv[])
{
	Mat *m=new Mat;
	if (argc == 2)
		*m = imread(argv[1]);
	if (m->empty())
    {
        cout << "File not found or empty image\n";
    }
	img = Ptr<Mat>(m);
	imshow("Original",*img.get());
    namedWindow( window_name, WINDOW_AUTOSIZE );

    /// Create a Trackbar for user to enter threshold
    createTrackbar( "a:",window_name, &aa, 400, PaillouFilter );
    createTrackbar( "w:", window_name, &ww, 400, PaillouFilter );
    PaillouFilter(0,NULL);
    waitKey();
    return 0;
}