OpenCV常用类和函数.md

OpenCV常用类和函数

读写图片

	读取指定文件路径内容：Imgcodecs.imread(filePath);
	读取MultipartFile文件内容：Imgcodecs.imdecode(new MatOfByte(file.getBytes()), Imgcodecs.IMREAD_UNCHANGED);
	保存图片：Imgcodecs.imwrite(filename, image);

	读取视频：
	// 打开摄像头或者视频文件
    VideoCapture capture = new VideoCapture();
    //capture.open(0);
    capture.open("D:/vcprojects/images/768x576.avi");
    Mat frame = new Mat();
    while(true) {
    	boolean have = capture.read(frame);
    	...
    }

    显示图片：
    HighGui.imshow("H",frame);
    HighGui.waitKey(0);

颜色空间转换

    Imgproc.cvtColor(srcImg,image,Imgproc.COLOR_BGR2HSV);

直方图

	Imgproc.calcHist(mv2, channels, new Mat(), histImg, histSize,ranges);

求解矩阵最小二乘解

	Core.solve(X, Y, A, Core.DECOMP_LU);

阈值化

	Imgproc.adaptiveThreshold(image,image,255,Imgproc.ADAPTIVE_THRESH_GAUSSIAN_C,Imgproc.THRESH_BINARY_INV,25,10);

画矩形，圆形

	Imgproc.rectangle(frame, rect,new Scalar(0, 255, 0),1);
	Imgproc.circle(frame,point,2,new Scalar(255,0,0),2);

计算均值

	Scalar scalar = Core.mean(imgDesc);

截取ROI

	imgROI.copyTo(imgDesc);

获取某个像素点的颜色值（rgb空间）

	double[] midPrgb0 = frame.get(y,x);

查找轮廓

	Imgproc.findContours(result, contours, hierarchy, Imgproc.RETR_EXTERNAL, Imgproc.CHAIN_APPROX_SIMPLE);

图割操作

	//实现图割操作 结果是一个二值图像
	Imgproc.grabCut(frame, result, rect, bgMat, fgMat, i, Imgproc.GC_INIT_WITH_RECT);

神经网络【yolo】

	Net net = Dnn.readNetFromDarknet(cfgFile, weights);

	Mat inputBlob = Dnn.blobFromImage(frame, scale, sz, new Scalar(0), false, false);   //Convert Mat to batch of images
	net.setInput(inputBlob);

	List<String> outNames = net.getUnconnectedOutLayersNames();
	net.forward(outs,outNames);
	MatOfInt outLayers = net.getUnconnectedOutLayers();

	String outLayerType = net.getLayer(new DictValue(layerid)).get_type();
	Mat detectionMat = outs.get(i);