Update Adaptive correction algorithm for illumination inhomogeneity image based on two-dimensional gamma function.cpp

Author: BBuf

Adaptive correction algorithm for illumination inhomogeneity image based on two-dimensional gamma function.cpp

@@ -0,0 +1,130 @@
+Mat RGB2HSV(Mat src) {
+	int row = src.rows;
+	int col = src.cols;
+	Mat dst(row, col, CV_32FC3);
+	for (int i = 0; i < row; i++) {
+		for (int j = 0; j < col; j++) {
+			float b = src.at<Vec3b>(i, j)[0] / 255.0;
+			float g = src.at<Vec3b>(i, j)[1] / 255.0;
+			float r = src.at<Vec3b>(i, j)[2] / 255.0;
+			float minn = min(r, min(g, b));
+			float maxx = max(r, max(g, b));
+			dst.at<Vec3f>(i, j)[2] = maxx; //V
+			float delta = maxx - minn;
+			float h, s;
+			if (maxx != 0) {
+				s = delta / maxx;
+			}
+			else {
+				s = 0;
+			}
+			if (r == maxx) {
+				h = (g - b) / delta;
+			}
+			else if (g == maxx) {
+				h = 2 + (b - r) / delta;
+			}
+			else {
+				h = 4 + (r - g) / delta;
+			}
+			h *= 60;
+			if (h < 0)
+				h += 360;
+			dst.at<Vec3f>(i, j)[0] = h;
+			dst.at<Vec3f>(i, j)[1] = s;
+		}
+	}
+	return dst;
+}
+
+Mat HSV2RGB(Mat src) {
+	int row = src.rows;
+	int col = src.cols;
+	Mat dst(row, col, CV_8UC3);
+	float r, g, b, h, s, v;
+	for (int i = 0; i < row; i++) {
+		for (int j = 0; j < col; j++) {
+			h = src.at<Vec3f>(i, j)[0];
+			s = src.at<Vec3f>(i, j)[1];
+			v = src.at<Vec3f>(i, j)[2];
+			if (s == 0) {
+				r = g = b = v;
+			}
+			else {
+				h /= 60;
+				int offset = floor(h);
+				float f = h - offset;
+				float p = v * (1 - s);
+				float q = v * (1 - s * f);
+				float t = v * (1 - s * (1 - f));
+				switch (offset)
+				{
+				case 0: r = v; g = t; b = p; break;
+				case 1: r = q; g = v; b = p; break;
+				case 2: r = p; g = v; b = t; break;
+				case 3: r = p; g = q; b = v; break;
+				case 4: r = t; g = p; b = v; break;
+				case 5: r = v; g = p; b = q; break;
+				default:
+					break;
+				}
+			}
+			dst.at<Vec3b>(i, j)[0] = int(b * 255);
+			dst.at<Vec3b>(i, j)[1] = int(g * 255);
+			dst.at<Vec3b>(i, j)[2] = int(r * 255);
+		}
+	}
+	return dst;
+}
+
+Mat work(Mat src) {
+	int row = src.rows;
+	int col = src.cols;
+	Mat now = RGB2HSV(src);
+	Mat H(row, col, CV_32FC1);
+	Mat S(row, col, CV_32FC1);
+	Mat V(row, col, CV_32FC1);
+	for (int i = 0; i < row; i++) {
+		for (int j = 0; j < col; j++) {
+			H.at<float>(i, j) = now.at<Vec3f>(i, j)[0];
+			S.at<float>(i, j) = now.at<Vec3f>(i, j)[1];
+			V.at<float>(i, j) = now.at<Vec3f>(i, j)[2];
+		}
+	}
+	int kernel_size = min(row, col);
+	if (kernel_size % 2 == 0) {
+		kernel_size -= 1;
+	}
+	float SIGMA1 = 15;
+	float SIGMA2 = 80;
+	float SIGMA3 = 250;
+	float q = sqrtf(2.0);
+	Mat F(row, col, CV_32FC1);
+	Mat F1(row, col, CV_32FC1);
+	Mat F2(row, col, CV_32FC1);
+	Mat F3(row, col, CV_32FC1);
+	GaussianBlur(V, F1, Size(kernel_size, kernel_size), SIGMA1 / q);
+	GaussianBlur(V, F2, Size(kernel_size, kernel_size), SIGMA2 / q);
+	GaussianBlur(V, F3, Size(kernel_size, kernel_size), SIGMA3 / q);
+	for (int i = 0; i < row; i++) {
+		for (int j = 0; j < col; j++) {
+			F.at <float>(i, j) = (F1.at<float>(i, j) + F2.at<float>(i, j) + F3.at<float>(i, j)) / 3.0;
+		}
+	}
+	float average = mean(F)[0];
+	Mat out(row, col, CV_32FC1);
+	for (int i = 0; i < row; i++) {
+		for (int j = 0; j < col; j++) {
+			float gamma = powf(0.5, (average - F.at<float>(i, j)) / average);
+			out.at<float>(i, j) = powf(V.at<float>(i, j), gamma);
+		}
+	}
+	vector <Mat> v;
+	v.push_back(H);
+	v.push_back(S);
+	v.push_back(out);
+	Mat merge_;
+	merge(v, merge_);
+	Mat dst = HSV2RGB(merge_);
+	return dst;
+}

README.md

@@ -25,3 +25,4 @@
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+- Adaptive correction algorithm for illumination inhomogeneity image based on two-dimensional gamma function.cpp C++复现了《基于二维伽马函数的光照不均匀图像自适应校正算法》这篇论文，对光照不均匀的图像有较好的校正效果，且不会像Retiex那样出现光晕。原理请看：https://blog.csdn.net/just_sort/article/details/88569129