// OpenCVApplication.cpp : Defines the entry point for the console application.
// Laborator PI, Nagy Imola, gr 30234

#include "stdafx.h"
#include "common.h"
#include <queue>
#include <random>
#include <vector>


/* Histogram display function - display a histogram using bars (simlilar to L3 / PI)
Input:
name - destination (output) window name
hist - pointer to the vector containing the histogram values
hist_cols - no. of bins (elements) in the histogram = histogram image width
hist_height - height of the histogram image
Call example:
showHistogram ("MyHist", hist_dir, 255, 200);
*/
void showHistogram(const string& name, int* hist, const int  hist_cols, const int hist_height)
{
	Mat imgHist(hist_height, hist_cols, CV_8UC3, CV_RGB(255, 255, 255)); // constructs a white image

	//computes histogram maximum
	int max_hist = 0;
	for (int i = 0; i<hist_cols; i++)
	if (hist[i] > max_hist)
		max_hist = hist[i];
	double scale = 1.0;
	scale = (double)hist_height / max_hist;
	int baseline = hist_height - 1;

	for (int x = 0; x < hist_cols; x++) {
		Point p1 = Point(x, baseline);
		Point p2 = Point(x, baseline - cvRound(hist[x] * scale));
		line(imgHist, p1, p2, CV_RGB(255, 0, 255)); // histogram bins colored in magenta
	}

	imshow(name, imgHist);
}

Mat rgb_to_yuv(Mat img) {

	Vec3b color;
	Mat yuv = Mat(img.size(), CV_8UC3);

	for (int i = 0; i < img.rows; i++) {
		for (int j = 0; j < img.cols; j++) {
			color = img.at<Vec3b>(i, j); //bgr
			yuv.at<Vec3b>(i, j)[0] = color[2] * .299000 + color[1] * .587000 + color[0] * .114000;
			yuv.at<Vec3b>(i, j)[1] = color[2] * -.168736 + color[1] * -.331264 + color[0] * .500000 + 128;
			yuv.at<Vec3b>(i, j)[2] = color[2] * .500000 + color[1] * -.418688 + color[0] * -.081312 + 128;
		}
	}
	return yuv;
}

Mat normalize_yuv(Mat img) {

	Mat yuv_normalized = Mat(img.size(), CV_8UC3);
	yuv_normalized = img.clone();
	for (int i = 0; i < img.rows; i++) {
		for (int j = 0; j < img.cols; j++) {

			yuv_normalized.at<Vec3b>(i, j)[0] = 128;

			float k;
			if (img.at<Vec3b>(i, j)[0] > 128) {
				k = yuv_normalized.at<Vec3b>(i, j)[0] / img.at<Vec3b>(i, j)[0];
			}
			else if (img.at<Vec3b>(i, j)[0] < 128) {
				k = (255 - img.at<Vec3b>(i, j)[0] )/ yuv_normalized.at<Vec3b>(i, j)[0];
			}
			else {
				k = 1;
			}
			yuv_normalized.at<Vec3b>(i, j)[1] = min((img.at<Vec3b>(i, j)[1] - 128) * k + 128, 255);
			yuv_normalized.at<Vec3b>(i, j)[2] = min((img.at<Vec3b>(i, j)[2] - 128) * k + 128, 255);
		}
	}
	return yuv_normalized;
}

void test() {
	char fname[MAX_PATH];
	while (openFileDlg(fname)) {
		Mat img = imread(fname, CV_LOAD_IMAGE_UNCHANGED);

		Mat yuv = rgb_to_yuv(img);
		Mat yuv_norm = normalize_yuv(yuv);

		Mat u = Mat(yuv_norm.rows, yuv_norm.cols, CV_8UC1);
		Mat v = Mat(yuv_norm.rows, yuv_norm.cols, CV_8UC1);

		for (int i = 0; i < u.rows; i++) {
			for (int j = 0; j < u.cols; j++)
			{
				u.at<uchar>(i, j) = yuv_norm.at<Vec3b>(i, j)[1];
				v.at<uchar>(i, j) = yuv_norm.at<Vec3b>(i, j)[2];
			}
		}


		imshow("original", img);
		imshow("mod", yuv_norm);
		imshow("u", u);
		imshow("v", v);
		waitKey(0);
	}

}

int main()
{
	test();
	return 0;
}