/*M///////////////////////////////////////////////////////////////////////////////////////
//
//  IMPORTANT: READ BEFORE DOWNLOADING, COPYING, INSTALLING OR USING.
//
//  By downloading, copying, installing or using the software you agree to this license.
//  If you do not agree to this license, do not download, install,
//  copy or use the software.
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// Copyright (C) 2013, Alfonso Sanchez-Beato, all rights reserved.
// Third party copyrights are property of their respective owners.
//
// Redistribution and use in source and binary forms, with or without modification,
// are permitted provided that the following conditions are met:
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//   * Redistribution's of source code must retain the above copyright notice,
//     this list of conditions and the following disclaimer.
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//   * Redistribution's in binary form must reproduce the above copyright notice,
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//   * The name of the copyright holders may not be used to endorse or promote products
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// This software is provided by the copyright holders and contributors "as is" and
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//M*/

#include "precomp.hpp"
#include <opencv2/imgproc.hpp>
#include "opencv2/reg/mapper.hpp"

namespace cv {
namespace reg {


////////////////////////////////////////////////////////////////////////////////////////////////////
void Mapper::gradient(const Mat& img1, const Mat& img2, Mat& Ix, Mat& Iy, Mat& It) const
{
    Size sz1 = img2.size();

    Mat xkern = (Mat_<double>(1, 3) << -1., 0., 1.)/2.;
    filter2D(img2, Ix, -1, xkern, Point(-1,-1), 0., BORDER_REPLICATE);

    Mat ykern = (Mat_<double>(3, 1) << -1., 0., 1.)/2.;
    filter2D(img2, Iy, -1, ykern, Point(-1,-1), 0., BORDER_REPLICATE);

    It = Mat::zeros(sz1, img1.type());
    It = img2 - img1;
}

////////////////////////////////////////////////////////////////////////////////////////////////////

template<typename _Tp>
void fillGridMatrices(const Mat img, Mat grid_r, Mat grid_c)
{
    if(img.channels() == 1) {
        for(int r_i = 0; r_i < img.rows; ++r_i) {
            for(int c_i = 0; c_i < img.cols; ++c_i) {
                grid_r.at<_Tp>(r_i, c_i) = (_Tp)r_i;
                grid_c.at<_Tp>(r_i, c_i) = (_Tp)c_i;
            }
        }
    } else {
        Vec<_Tp, 3> ones((_Tp)1, (_Tp)1, (_Tp)1);
        for(int r_i = 0; r_i < img.rows; ++r_i) {
            for(int c_i = 0; c_i < img.cols; ++c_i) {
                grid_r.at< Vec<_Tp, 3> >(r_i, c_i) = (_Tp)r_i*ones;
                grid_c.at< Vec<_Tp, 3> >(r_i, c_i) = (_Tp)c_i*ones;
            }
        }
    }
}

void Mapper::grid(const Mat& img, Mat& grid_r, Mat& grid_c) const
{
    CV_DbgAssert(img.channels() == 1 || img.channels() == 3);

    // Matrices with reference frame coordinates
    grid_r.create(img.size(), img.type());
    grid_c.create(img.size(), img.type());

    if(img.depth() == CV_8U)
        fillGridMatrices<uchar>(img, grid_r, grid_c);
    if(img.depth() == CV_16U)
        fillGridMatrices<ushort>(img, grid_r, grid_c);
    else if(img.depth() == CV_32F)
        fillGridMatrices<float>(img, grid_r, grid_c);
    else if(img.depth() == CV_64F)
        fillGridMatrices<double>(img, grid_r, grid_c);
}


}}  // namespace cv::reg