opencv學習筆記29-圖像矩

只用來記錄學習筆記

Mat src, gray_src, temp, dst;
const char* input_title = "input";
const char* output_title = "output";
const char* trackbar_title = "output";
int threshold_value = 80;
int threshold_max = 255;
RNG rng(12345);
void Demo_Moments(int,void*);

	cvtColor(src, gray_src, CV_BGR2GRAY); //轉灰度圖像
	GaussianBlur(gray_src, gray_src, Size(3, 3), 0,0); //高斯模糊

	createTrackbar(trackbar_title, output_title, &threshold_value, threshold_max, Demo_Moments);//滑塊改變閾值
	Demo_Moments(0, 0);

	void Demo_Moments(int, void*) {
	Mat canny_output;
	vector<vector<Point>> contours; //輪廓
	vector<Vec4i> hierachy;

	Canny(gray_src, canny_output, threshold_value, threshold_value * 2, 3, false); //邊緣檢測
	findContours(canny_output, contours, hierachy, RETR_TREE, CHAIN_APPROX_SIMPLE, Point(-1, -1));//輪廓發現

	vector<Moments> contours_moments(contours.size());
	vector<Point2f> ccs(contours.size());
	for (size_t i = 0; i < contours.size(); i++) { //循環遍歷輪廓
		contours_moments[i] = moments(contours[i]);//中心距 
		ccs[i] = Point(static_cast<float>(contours_moments[i].m10 / contours_moments[i].m00), static_cast<float>(contours_moments[i].m01 / contours_moments[i].m00));//圓心
	}

	Mat drawimg;
	src.copyTo(drawimg);
	for (size_t i = 0; i < contours.size(); i++) {
		Scalar color = Scalar(rng.uniform(0, 255), rng.uniform(0, 255), rng.uniform(0, 255));
		cout << "contours " << i << "area: " << contourArea(contours[i]) << "are length:" << arcLength(contours[i],false) << endl;
		//contourArea輪廓面積算法;
		//arcLength:計算封閉輪廓的周長或曲線的長度
		drawContours(drawimg, contours, i, color, 2, 8, hierachy, 0, Point(0, 0));//繪製輪廓
		circle(drawimg, ccs[i], 2, color, 2, 8); //繪製圓心
	}

	imshow(output_title, drawimg);
	return;
}