6주차 수업 끝

ch05/histogram/main.cpp

@@ -0,0 +1,81 @@
+#include <iostream>
+#include "opencv2/opencv.hpp"
+
+using namespace std;
+using namespace cv;
+
+Mat calcGrayHist(const Mat& img);
+Mat getGrayHistImage(const Mat& hist);
+Mat histogram_stretching(const Mat& src);
+
+int main() {
+	VideoCapture video;
+	video.open("..\\..\\resources\\images\\vtest.avi");
+	int fps = video.get(CAP_PROP_FPS);
+
+	Mat src;
+
+	while (true) {
+		video >> src;
+		if (src.empty())
+			return 1;
+		imshow("sample", src);
+		if (waitKey(1000 / fps) == 27)
+			break;
+	}
+	cvtColor(src, src, COLOR_BGR2GRAY);
+	src = src + 20;
+	Mat src_hist_img = getGrayHistImage(calcGrayHist(src));
+	Mat dst = histogram_stretching(src);
+	Mat dst_hist_img = getGrayHistImage(calcGrayHist(dst));
+
+	imshow("src", src);
+	imshow("srcHist", src_hist_img);
+
+	imshow("dst", dst);
+	imshow("dstHist", dst_hist_img);
+
+	waitKey();
+	destroyAllWindows();
+
+	return 0;
+}
+
+Mat calcGrayHist(const Mat& img) {
+	CV_Assert(img.type() == CV_8UC1);
+
+	Mat hist;
+	int channels[] = { 0, };
+	int dims = 1;
+	const int histSize[] = { 256, };
+	float graylevel[] = { 0, 256 };
+	const float* ranges[] = { graylevel };
+
+	calcHist(&img, 1, channels, noArray(), hist, dims, histSize, ranges);
+
+	return hist;
+}
+
+Mat getGrayHistImage(const Mat& hist) {
+	CV_Assert(hist.type() == CV_32FC1);
+	CV_Assert(hist.size() == Size(1, 256));
+
+	double histMax;
+	minMaxLoc(hist, 0, &histMax);
+
+	Mat imgHist(100, 256, CV_8UC1, Scalar(255));
+	for (int i = 0; i < 256; i++) {
+		line(imgHist, Point(i, 100), Point(i, 100 - cvRound(hist.at<float>(i, 0) * 100 / histMax)), Scalar(0));
+	}
+
+	return imgHist;
+}
+
+Mat histogram_stretching(const Mat &src) {
+	double gmin, gmax;
+	minMaxLoc(src, &gmin, &gmax);
+
+	Mat dst = (src - gmin) * 255 / (gmax - gmin);
+
+	return dst;
+}