content: import java.util.ArrayList;
  import java.util.List;
  
  import org.opencv.core.Core;
  import org.opencv.core.Core.MinMaxLocResult;
  import org.opencv.core.CvType;
  import org.opencv.core.Mat;
  import org.opencv.core.MatOfPoint;
  import org.opencv.core.MatOfPoint2f;
  import org.opencv.core.Point;
  import org.opencv.core.Scalar;
  import org.opencv.core.Size;
  import org.opencv.highgui.HighGui;
  import org.opencv.imgproc.Imgproc;
  
  class PointPolygonTest {
      public void run() {
          /// Create an image
          int r = 100;
          Mat src = Mat.zeros(new Size(4 * r, 4 * r), CvType.CV_8U);
  
          /// Create a sequence of points to make a contour
          List<Point> vert = new ArrayList<>(6);
          vert.add(new Point(3 * r / 2, 1.34 * r));
          vert.add(new Point(1 * r, 2 * r));
          vert.add(new Point(3 * r / 2, 2.866 * r));
          vert.add(new Point(5 * r / 2, 2.866 * r));
          vert.add(new Point(3 * r, 2 * r));
          vert.add(new Point(5 * r / 2, 1.34 * r));
  
          /// Draw it in src
          for (int i = 0; i < 6; i++) {
              Imgproc.line(src, vert.get(i), vert.get((i + 1) % 6), new Scalar(255), 3);
          }
  
          /// Get the contours
          List<MatOfPoint> contours = new ArrayList<>();
          Mat hierarchy = new Mat();
          Imgproc.findContours(src, contours, hierarchy, Imgproc.RETR_TREE, Imgproc.CHAIN_APPROX_SIMPLE);
  
          /// Calculate the distances to the contour
          Mat rawDist = new Mat(src.size(), CvType.CV_32F);
          float[] rawDistData = new float[(int) (rawDist.total() * rawDist.channels())];
          for (int i = 0; i < src.rows(); i++) {
              for (int j = 0; j < src.cols(); j++) {
                  rawDistData[i * src.cols() + j] = (float) Imgproc
                          .pointPolygonTest(new MatOfPoint2f(contours.get(0).toArray()), new Point(j, i), true);
              }
          }
          rawDist.put(0, 0, rawDistData);
  
          MinMaxLocResult res = Core.minMaxLoc(rawDist);
          double minVal = Math.abs(res.minVal);
          double maxVal = Math.abs(res.maxVal);
  
          /// Depicting the distances graphically
          Mat drawing = Mat.zeros(src.size(), CvType.CV_8UC3);
          byte[] drawingData = new byte[(int) (drawing.total() * drawing.channels())];
          for (int i = 0; i < src.rows(); i++) {
              for (int j = 0; j < src.cols(); j++) {
                  if (rawDistData[i * src.cols() + j] < 0) {
                      drawingData[(i * src.cols() + j) * 3] =
                              (byte) (255 - Math.abs(rawDistData[i * src.cols() + j]) * 255 / minVal);
                  } else if (rawDistData[i * src.cols() + j] > 0) {
                      drawingData[(i * src.cols() + j) * 3 + 2] =
                              (byte) (255 - rawDistData[i * src.cols() + j] * 255 / maxVal);
                  } else {
                      drawingData[(i * src.cols() + j) * 3] = (byte) 255;
                      drawingData[(i * src.cols() + j) * 3 + 1] = (byte) 255;
                      drawingData[(i * src.cols() + j) * 3 + 2] = (byte) 255;
                  }
              }
          }
          drawing.put(0, 0, drawingData);
          Imgproc.circle(drawing, res.maxLoc, (int)res.maxVal, new Scalar(255, 255, 255), 2, 8, 0);
  
          /// Show your results
          HighGui.imshow("Source", src);
          HighGui.imshow("Distance and inscribed circle", drawing);
  
          HighGui.waitKey();
          System.exit(0);
      }
  }
  
  public class PointPolygonTestDemo {
      public static void main(String[] args) {
          // Load the native OpenCV library
          System.loadLibrary(Core.NATIVE_LIBRARY_NAME);
  
          new PointPolygonTest().run();
      }
  
  }
  