--- /dev/null
+/**
+ * @function pointPolygonTest_demo.cpp
+ * @brief Demo code to use the pointPolygonTest function...fairly easy
+ * @author OpenCV team
+ */
+
+#include "opencv2/highgui/highgui.hpp"
+#include "opencv2/imgproc/imgproc.hpp"
+#include <iostream>
+#include <stdio.h>
+#include <stdlib.h>
+
+using namespace cv;
+using namespace std;
+
+/**
+ * @function main
+ */
+int main( int argc, char** argv )
+{
+ /// Create an image
+ const int r = 100;
+ Mat src = Mat::zeros( Size( 4*r, 4*r ), CV_8UC1 );
+
+ /// Create a sequence of points to make a contour:
+ vector<Point2f> vert(6);
+
+ vert[0] = Point( 1.5*r, 1.34*r );
+ vert[1] = Point( 1*r, 2*r );
+ vert[2] = Point( 1.5*r, 2.866*r );
+ vert[3] = Point( 2.5*r, 2.866*r );
+ vert[4] = Point( 3*r, 2*r );
+ vert[5] = Point( 2.5*r, 1.34*r );
+
+ /// Draw it in src
+ for( int j = 0; j < 6; j++ )
+ { line( src, vert[j], vert[(j+1)%6], Scalar( 255 ), 3, 8 ); }
+
+ /// Get the contours
+ vector<vector<Point> > contours; vector<Vec4i> hierarchy;
+ Mat src_copy = src.clone();
+
+ findContours( src_copy, contours, hierarchy, RETR_TREE, CHAIN_APPROX_SIMPLE);
+
+ /// Calculate the distances to the contour
+ Mat raw_dist( src.size(), CV_32FC1 );
+
+ for( int j = 0; j < src.rows; j++ )
+ { for( int i = 0; i < src.cols; i++ )
+ { raw_dist.at<float>(j,i) = pointPolygonTest( contours[0], Point2f(i,j), true ); }
+ }
+
+ double minVal; double maxVal;
+ minMaxLoc( raw_dist, &minVal, &maxVal, 0, 0, Mat() );
+ minVal = abs(minVal); maxVal = abs(maxVal);
+
+ /// Depicting the distances graphically
+ Mat drawing = Mat::zeros( src.size(), CV_8UC3 );
+
+ for( int j = 0; j < src.rows; j++ )
+ { for( int i = 0; i < src.cols; i++ )
+ {
+ if( raw_dist.at<float>(j,i) < 0 )
+ { drawing.at<Vec3b>(j,i)[0] = 255 - (int) abs(raw_dist.at<float>(j,i))*255/minVal; }
+ else if( raw_dist.at<float>(j,i) > 0 )
+ { drawing.at<Vec3b>(j,i)[2] = 255 - (int) raw_dist.at<float>(j,i)*255/maxVal; }
+ else
+ { drawing.at<Vec3b>(j,i)[0] = 255; drawing.at<Vec3b>(j,i)[1] = 255; drawing.at<Vec3b>(j,i)[2] = 255; }
+ }
+ }
+
+ /// Create Window and show your results
+ char* source_window = "Source";
+ namedWindow( source_window, CV_WINDOW_AUTOSIZE );
+ imshow( source_window, src );
+ namedWindow( "Distance", CV_WINDOW_AUTOSIZE );
+ imshow( "Distance", drawing );
+
+ waitKey(0);
+ return(0);
+}
+
+