void calcul_histo() {
	Mat src;
	char fname[MAX_PATH];

	while (openFileDlg(fname))
	{
		src = imread(fname, CV_LOAD_IMAGE_GRAYSCALE);

		int h[256] = { 0 };
		int M = src.rows *  src.cols;

		for (int i = 0; i < src.rows; i++) {
			for (int j = 0; j < src.cols; j++) {
				uchar g = src.at<uchar>(i, j);
				h[g] ++;
			}
		}

		showHistogram("Histo", h, 255, 200);
		imshow("Sursa", src);

		float p[256] = { 0.0f };
		for (int g = 0; g < 256; g++) {
			p[g] = (float)h[g] / M;
		}

		float medie = 0.0f;

		for (int g = 0; g < 256; g++) {
			medie += g * p[g];
		}

		printf("Medie = %.2f\n", medie);

		float variance = 0.0f;
		for (int g = 0; g < 256; g++)
			variance += (g - medie) * (g - medie) * p[g];
		float sigma = sqrt(variance);
		printf("Deviatia standard = %.2f\n\n", sigma);

		waitKey(0);
	}
}

void binarizare_automata() {

	Mat src;
	char fname[MAX_PATH];
	int iMin = 0, iMax = 0;
	while (openFileDlg(fname))
	{
		src = imread(fname, CV_LOAD_IMAGE_GRAYSCALE);
		Mat dst = src.clone();

		int h[256] = { 0 };
		int M = src.rows *  src.cols;

		for (int i = 0; i < src.rows; i++) {
			for (int j = 0; j < src.cols; j++) {
				uchar g = src.at<uchar>(i, j);
				h[g] ++;
			}
		}

		for (int g = 0; g < 255; g++) {
			if (h[g] != 0) {
				iMin = g; //val intensitate minima
				break;
			}
		}

		for (int g = 255; g > 0; g--) {
			if (h[g] != 0) {
				iMax = g; //val intensitate maxima
				break;
			}
		}

		float T1 = 0.0f, T2 = 0.0f;
		float medieG1 = 0.0f, medieG2 = 0.0f;
		int n1 = 0, n2 = 0;
		int first = 0;


		T1 = (float)(iMin + iMax) / 2;
		T2 = T1 + 1.0f;

		while (T2 - T1 > 0.1) {
			if (first == 0)
				first++;
			else T1 = T2;

			n1 = n2 = 0;

			for (int f = iMin; f <= (int)T1; f++)
			{
				medieG1 += f*h[f];
				n1 += h[f];
			}

			medieG1 = ((float)1 / n1) * medieG1;

			for (int f = (int)T1 + 1; f <= iMax; f++)
			{
				medieG2 += f*h[f];
				n2 += h[f];
			}
			medieG2 = ((float)1 / n2) * medieG2;

			T2 = (float)(medieG1 + medieG2) / 2;
		}

		printf("prag = %f\n", T2);
		int T = (int)T2;

		for (int i = 0; i < src.rows; i++)
		{
			for (int j = 0; j < src.cols; j++)
			{
				if (src.at<uchar>(i, j) <= T)
					dst.at<uchar>(i, j) = 0;
				else dst.at<uchar>(i, j) = 255;
			}
		}

		imshow("Sursa", src);
		imshow("Destinatie", dst);

		waitKey(0);
	}

}

void modificare_contrast() {
	Mat src;
	int iMin = 0, iMax = 0;
	int gInMin = 0, gInMax = 0;
	// Read image from file
	char fname[MAX_PATH];

	while (openFileDlg(fname))
	{
		src = imread(fname, CV_LOAD_IMAGE_GRAYSCALE);
		Mat dst = src.clone();

		int h[256] = { 0 };

		for (int i = 0; i < src.rows; i++)
		{
			for (int j = 0; j < src.cols; j++)
			{
				uchar g = src.at<uchar>(i, j);
				h[g]++;
			}
		}

		showHistogram("Src Hist", h, 255, 200);


		for (int g = 0; g < 255; g++) {
			if (h[g] != 0) {
				gInMin = g; //val intensitate minima
				break;
			}
		}

		for (int g = 255; g > 0; g--) {
			if (h[g] != 0) {
				gInMax = g; //val intensitate maxima
				break;
			}
		}

		int gOutMin = 0, gOutMax = 0;
		int gAux = 0;

		printf("gOutMin = "); scanf("%d", &gOutMin);
		printf("gOutMax = "); scanf("%d", &gOutMax);



		for (int i = 0; i < src.rows; i++)
		{
			for (int j = 0; j < src.cols; j++)
			{
				gAux = gOutMin + (src.at<uchar>(i, j) - gInMin) * (gOutMax - gOutMin) / (gInMax - gInMin);

				if (gAux > 255)
					gAux = 255;
				else if (gAux < 0)
					gAux = 0;

				dst.at<uchar>(i, j) = gAux;
			}
		}

		int hd[256] = { 0 };

		for (int i = 0; i < src.rows; i++)
		{
			for (int j = 0; j < src.cols; j++)
			{
				uchar g = dst.at<uchar>(i, j);
				hd[g]++;
			}
		}

		showHistogram("Hist Destinatie", hd, 255, 200);

		imshow("Img sursa", src);
		imshow("Img destinatie", dst);

		waitKey(0);
	}
}

void corectie_gamma()
{
	Mat src;
	// Read image from file
	char fname[MAX_PATH];

	while (openFileDlg(fname))
	{
		src = imread(fname, CV_LOAD_IMAGE_GRAYSCALE);
		Mat dst = src.clone();

		float gamma = 0.0f;

		printf("gamma = "); scanf("%f", &gamma);

		int h[256] = { 0 };

		for (int i = 0; i < src.rows; i++)
		{
			for (int j = 0; j < src.cols; j++)
			{
				uchar g = src.at<uchar>(i, j);
				h[g]++;
			}
		}

		showHistogram("Src Hist", h, 255, 200);

		int g = 0;
		int gAux = 0;
		for (int i = 0; i < src.rows; i++)
		{
			for (int j = 0; j < src.cols; j++)
			{
				g = src.at<uchar>(i, j);
				gAux = 255 * pow((float)g / 255, gamma);

				if (gAux > 255) gAux = 255;
				else if (gAux < 0) gAux = 0;

				dst.at<uchar>(i, j) = gAux;
			}
		}

		int hd[256] = { 0 };

		for (int i = 0; i < src.rows; i++)
		{
			for (int j = 0; j < src.cols; j++)
			{
				uchar g = dst.at<uchar>(i, j);
				hd[g]++;
			}
		}

		showHistogram("Hist Destinatie", hd, 255, 200);

		imshow("Img sursa", src);
		imshow("Img destinatie", dst);

		waitKey(0);
	}
}

void egalizare_histograma(){
	Mat src;
	char fname[MAX_PATH];

	while (openFileDlg(fname))
	{
		src = imread(fname, CV_LOAD_IMAGE_GRAYSCALE);
		Mat dst = src.clone();

		int h[256] = { 0 };
		int M = src.rows * src.cols;

		for (int i = 0; i < src.rows; i++)
		{
			for (int j = 0; j < src.cols; j++)
			{
				uchar g = src.at<uchar>(i, j);
				h[g]++;
			}
		}

		showHistogram("Src Hist", h, 255, 200);
		int hc[256] = { 0 };

		hc[0] = h[0];
		for (int g = 1; g < 256; g++)
		{
			hc[g] = hc[g - 1] + h[g];
		}

		showHistogram("Hist Cumulativa", hc, 255, 200);

		int tab[256] = { 0 };
		for (int g = 0; g < 256; g++)
		{
			tab[g] = 255 * hc[g] / M;
		}

		for (int i = 0; i < src.rows; i++)
		{
			for (int j = 0; j < src.cols; j++)
			{
				dst.at<uchar>(i, j) = tab[src.at<uchar>(i, j)];
			}
		}

		int hd[256] = { 0 };

		for (int i = 0; i < src.rows; i++)
		{
			for (int j = 0; j < src.cols; j++)
			{
				uchar g = dst.at<uchar>(i, j);
				hd[g]++;
			}
		}

		showHistogram("Hist Destinatie", hd, 255, 200);

		imshow("Sursa", src);
		imshow("Destinatie", dst);
		waitKey(0);
	}
}