Update imgproc.hpp

modules/imgproc/include/opencv2/imgproc.hpp

@@ -1785,7 +1785,7 @@ Example: :
         GaussianBlur( gray, gray, Size(9, 9), 2, 2 );
         vector<Vec3f> circles;
         HoughCircles(gray, circles, HOUGH_GRADIENT,
-                     2, gray->rows/4, 200, 100 );
+                     2, gray.rows/4, 200, 100 );
         for( size_t i = 0; i < circles.size(); i++ )
         {
              Point center(cvRound(circles[i][0]), cvRound(circles[i][1]));