diff --git a/samples/cpp/tutorial_code/ImgTrans/HoughCircle_Demo.cpp b/samples/cpp/tutorial_code/ImgTrans/HoughCircle_Demo.cpp index 0790d903cd..0522e1892f 100644 --- a/samples/cpp/tutorial_code/ImgTrans/HoughCircle_Demo.cpp +++ b/samples/cpp/tutorial_code/ImgTrans/HoughCircle_Demo.cpp @@ -6,6 +6,7 @@ #include "opencv2/highgui/highgui.hpp" #include "opencv2/imgproc/imgproc.hpp" +#include using namespace cv; @@ -55,7 +56,11 @@ int main(int, char** argv) src = imread( argv[1], 1 ); if( !src.data ) - { return -1; } + { + std::cerr<<"Invalid input image\n"; + std::cout<<"Usage : tutorial_HoughCircle_Demo \n"; + return -1; + } // Convert it to gray cvtColor( src, src_gray, COLOR_BGR2GRAY );