统计下图中的对象个数

主要方法：高斯滤波函数，Canny边缘检测函数，形态学闭运算，寻找并绘制轮廓等。

原文来自公众号：OpenCV学堂 gloomyfish

结果：

代码：

Mat srcImage = imread("1.jpg");
namedWindow("原始图");
imshow("原始图", srcImage);
 
Mat gaussImage;
GaussianBlur(srcImage, gaussImage, Size(3, 3), 0);
namedWindow("高斯滤波图");
imshow("高斯滤波图", gaussImage);
 
Mat grayImage;
cvtColor(gaussImage, grayImage, COLOR_RGB2GRAY);
 
Mat cannyImage;
Canny(grayImage, cannyImage, 50, 100);
namedWindow("cannyImage");
imshow("cannyImage", cannyImage);
 
Mat kernal = getStructuringElement(MORPH_ELLIPSE, Size(10, 10));
 
Mat closeImage;
morphologyEx(cannyImage, closeImage, MORPH_CLOSE, kernal);
namedWindow("closeImage");
imshow("closeImage", closeImage);
 
vector<vector<Point> > contours;
vector<Vec4i> hierarchy;
findContours(closeImage, contours, hierarchy, CV_RETR_EXTERNAL, CV_CHAIN_APPROX_SIMPLE);
 
int count = 0;
for (int i = 0; i < contours.size(); i++)
{
	double area = contourArea(contours[i]);
	if (area < 100) continue;
 
	count++;
	RotatedRect rect = minAreaRect(contours[i]);
 
	Point2f rectVertex[4];
	rect.points(rectVertex);
 
	for (int i = 0; i < 4; i++)
	{
		line(srcImage, rectVertex[i], rectVertex[(i + 1) % 4], Scalar(100, 255, 0), 2, 8);
	}
}
 
namedWindow("原始图2");
imshow("原始图2", srcImage);
imwrite("result.jpg", srcImage);
 
waitKey(0);