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#include "precomp.hpp"
#include "opencv2/photo.hpp"
#include "hdr_common.hpp"

namespace cv
{

void checkImageDimensions(const std::vector<Mat>& images)
{
    CV_Assert(!images.empty());
    int width = images[0].cols;
    int height = images[0].rows;
    int type = images[0].type();

    for(size_t i = 0; i < images.size(); i++) {
        CV_Assert(images[i].cols == width && images[i].rows == height);
        CV_Assert(images[i].type() == type);
    }
}

Mat tringleWeights()
{
    Mat w(256, 1, CV_32F);
    for(int i = 0; i < 256; i++) {
        w.at<float>(i) = i < 128 ? i + 1.0f : 256.0f - i;
    }
    return w;
}

Mat RobertsonWeights()
{
    Mat weight(256, 1, CV_32FC3);
    for(int i = 0; i < 256; i++) {
        float value = exp(-4.0f * pow(i - 127.5f, 2.0f) / pow(127.5f, 2.0f));
        for(int c = 0; c < 3; c++) {
            weight.at<Vec3f>(i)[c] = value;
        }
    }
    return weight;
}

void mapLuminance(Mat src, Mat dst, Mat lum, Mat new_lum, float saturation)
{
    std::vector<Mat> channels(3);
    split(src, channels);
    for(int i = 0; i < 3; i++) {
        channels[i] = channels[i].mul(1.0f / lum);
        pow(channels[i], saturation, channels[i]);
        channels[i] = channels[i].mul(new_lum);
    }
    merge(channels, dst);
}

Mat linearResponse(int channels)
{
    Mat single_response = Mat(256, 1, CV_32F);
    for(int i = 1; i < 256; i++) {
        single_response.at<float>(i) = static_cast<float>(i);
    }
    single_response.at<float>(0) = static_cast<float>(1);

    std::vector<Mat> splitted(channels);
    for(int c = 0; c < channels; c++) {
        splitted[c] = single_response;
    }
    Mat result;
    merge(splitted, result);
    return result;
}

};