如何使用java中的opencv检测最大正方形(在图像的中心)的四个角点
我已经使用findContours解决了这个问题。
原始图像
输出图像
请在下面找到代码。我现在不知道如何检测中心正方形的终点。我尝试使用HoughLinesP检测线,但它仅返回1条垂直线,而不是全部提供4条线。
System.loadLibrary(Core.NATIVE_LIBRARY_NAME);
System.loadLibrary(Core.NATIVE_LIBRARY_NAME);
String path = "/Users/saurabhsaluja/Desktop/cimg.jpg";
Mat img = Imgcodecs.imread(path);
Mat destination = new Mat(img.rows(),img.cols(),img.type());
Core.addWeighted(img, 1.3, destination, -0.7, 0, destination);
Mat cannyOutput = new Mat();
int threshold = 15;
Mat srcGray = new Mat();
Imgproc.cvtColor(destination, srcGray, Imgproc.COLOR_BGR2GRAY);
Imgproc.Canny(srcGray, cannyOutput, threshold, threshold* 4);
Mat element = Imgproc.getStructuringElement(Imgproc.MORPH_RECT, new Size(10,10));
Mat element2 = Imgproc.getStructuringElement(Imgproc.MORPH_RECT, new Size(10,10));
Imgproc.dilate(cannyOutput, cannyOutput, element);
Imgproc.dilate(cannyOutput, cannyOutput, element2);
element = Imgproc.getStructuringElement(Imgproc.MORPH_RECT, new Size(9,9));
element2 = Imgproc.getStructuringElement(Imgproc.MORPH_RECT, new Size(9,9));
Imgproc.erode(cannyOutput, cannyOutput, element);
Imgproc.erode(cannyOutput, cannyOutput, element2);
Imgcodecs.imwrite("/Users/saurabhsaluja/Desktop/cannyOutput.jpg", cannyOutput); //THE IMAGE YOU ARE LOOKING AT
Mat lines = new Mat();
Imgproc.HoughLinesP(cannyOutput, lines, 1, Math.PI / 180, 50, 20, 20);
for(int i = 0; i < lines.cols(); i++) {
double[] val = lines.get(0, i);
Imgproc.line(img, new Point(val[0], val[1]), new Point(val[2], val[3]), new Scalar(0, 0, 255), 2);
}
Imgcodecs.imwrite("/Users/saurabhsaluja/Desktop/finalimg.jpg", img);
解决方案:
List<MatOfPoint> contours = new ArrayList<MatOfPoint>();
Imgproc.findContours(cannyOutput, contours, new Mat(), Imgproc.RETR_LIST, Imgproc.CHAIN_APPROX_SIMPLE);
double inf = 0;
Rect max_rect = null;
for(int i=0; i< contours.size();i++){
Rect rect = Imgproc.boundingRect(contours.get(i));
double area = rect.area();
if(inf < area) {
max_rect = rect;
inf = area;
//Imgcodecs.imwrite("/Users/saurabhsaluja/Desktop/input"+i+".jpg", img);
}
if(area > 50000) {
System.out.println(area);
Imgproc.rectangle(img, new Point(rect.x,rect.y), new Point(rect.x+rect.width,rect.y+rect.height),new Scalar(0,0,0),5);
}
}
现在只需查看每个柜台的面积即可获得最大的收益。
谢谢。解决方案图片:
List<MatOfPoint> contours = new ArrayList<MatOfPoint>();
Imgproc.findContours(cannyOutput, contours, new Mat(), Imgproc.RETR_LIST, Imgproc.CHAIN_APPROX_SIMPLE);
double inf = 0;
Rect max_rect = null;
for(int i=0; i< contours.size();i++){
Rect rect = Imgproc.boundingRect(contours.get(i));
double area = rect.area();
if(inf < area) {
max_rect = rect;
inf = area;
//Imgcodecs.imwrite("/Users/saurabhsaluja/Desktop/input"+i+".jpg", img);
}
if(area > 50000) {
System.out.println(area);
Imgproc.rectangle(img, new Point(rect.x,rect.y), new Point(rect.x+rect.width,rect.y+rect.height),new Scalar(0,0,0),5);
}
}
[[输出问题中添加的图像]