Syntax error How to draw geometrical shapes on image using OpenCV Java Library?

How to draw geometrical shapes on image using OpenCV Java Library?

The org.opencv.imgproc package of Java OpenCV library contains a class named Imgproc this class provies various methods such as, resize(), wrapAffine(), filter2D, to process an input image.

In addition to them It provides a set of method to draw geometrical shapes on images, Following are some of them −

Shape Method and Description
Ellipse You can draw an ellipse on an image using the ellipse() method.
Circle You can draw a circle on an image using the circle() method.
Rectangle You can draw a rectangle on an image using the rectangle() method.
Polygon You can draw a polygon on an image using the polygon() method.
Line You can draw a line on an image using the line() method

Example

Following Java example draws various shapes on a blank OpenCV image −

import org.opencv.core.Core;
import org.opencv.core.Mat;
import org.opencv.core.MatOfPoint;
import org.opencv.core.Point;
import org.opencv.core.RotatedRect;
import org.opencv.core.Scalar;
import org.opencv.core.Size;
import org.opencv.imgcodecs.Imgcodecs;
import org.opencv.imgproc.Imgproc;
import org.opencv.highgui.HighGui;
public class DrawingGeometricalShapes {
   public static void main(String args[]) {
      System.loadLibrary( Core.NATIVE_LIBRARY_NAME );
      Mat src = Imgcodecs.imread("D:\blank.jpg");
      Scalar color = new Scalar(0, 0, 120);
      //Drawing a Circle
      Imgproc.circle(src, new Point(75, 65), 40, color, Imgproc.FILLED);
      // Drawing an Ellipse
      Imgproc.ellipse(src, new RotatedRect(new Point(330, 60), new Size(100, 65), 180), color, Imgproc.FILLED);
      //Drawing a line
      Imgproc.line(src, new Point(540,30), new Point(540, 90), color, 5);
      //Drawing filled polygon
      List<MatOfPoint> list = new ArrayList();
      list.add(new MatOfPoint (
         new Point(410, 60), new Point(430, 30),
         new Point(470, 30), new Point(490, 60),
         new Point(470, 100), new Point(430, 100))
      );
      Imgproc.fillPoly (src, list, color, 8);
      //Drawing a Rectangle
      Imgproc.rectangle(src, new Point(150, 30), new Point(250, 95),color, Imgproc.FILLED);
      HighGui.imshow("Geometrical shapes", src);
      HighGui.waitKey();
   }
}

Output

Updated on: 2020-04-10T07:44:11+05:30

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