Merge pull request #883 from sovrasov:structured_edge_det_rounding_fix

modules/ximgproc/samples/structured_edge_detection.cpp

@@ -7,6 +7,7 @@ https://github.com/opencv/opencv_extra/blob/master/testdata/cv/ximgproc/model.ym
 #include <opencv2/ximgproc.hpp>
 #include "opencv2/highgui.hpp"
 #include "opencv2/core/utility.hpp"
+#include <iostream>
 
 using namespace cv;
 using namespace cv::ximgproc;
@@ -21,52 +22,51 @@ const char* keys =
 int main( int argc, const char** argv )
 {
     bool printHelp = ( argc == 1 );
-    printHelp = printHelp || ( argc == 2 && std::string(argv[1]) == "--help" );
-    printHelp = printHelp || ( argc == 2 && std::string(argv[1]) == "-h" );
+    printHelp = printHelp || ( argc == 2 && String(argv[1]) == "--help" );
+    printHelp = printHelp || ( argc == 2 && String(argv[1]) == "-h" );
 
     if ( printHelp )
     {
-        printf("\nThis sample demonstrates structured forests for fast edge detection\n"
+        std::cout << "\nThis sample demonstrates structured forests for fast edge detection\n"
                "Call:\n"
-               "    structured_edge_detection -i=in_image_name -m=model_name [-o=out_image_name]\n\n");
+               "    structured_edge_detection -i=in_image_name -m=model_name [-o=out_image_name]\n\n";
         return 0;
     }
 
-    cv::CommandLineParser parser(argc, argv, keys);
+    CommandLineParser parser(argc, argv, keys);
     if ( !parser.check() )
     {
         parser.printErrors();
         return -1;
     }
 
-    std::string modelFilename = parser.get<std::string>("m");
-    std::string inFilename = parser.get<std::string>("i");
-    std::string outFilename = parser.get<std::string>("o");
+    String modelFilename = parser.get<String>("m");
+    String inFilename = parser.get<String>("i");
+    String outFilename = parser.get<String>("o");
 
-    cv::Mat image = cv::imread(inFilename, 1);
+    Mat image = imread(inFilename, 1);
     if ( image.empty() )
-    {
-        printf("Cannot read image file: %s\n", inFilename.c_str());
-        return -1;
-    }
+        CV_Error(Error::StsError, String("Cannot read image file: ") + inFilename);
 
-    image.convertTo(image, cv::DataType<float>::type, 1/255.0);
+    if ( modelFilename.size() == 0)
+        CV_Error(Error::StsError, String("Empty model name"));
 
-    cv::Mat edges(image.size(), image.type());
+    image.convertTo(image, DataType<float>::type, 1/255.0);
 
-    cv::Ptr<StructuredEdgeDetection> pDollar =
+    Mat edges(image.size(), image.type());
+
+    Ptr<StructuredEdgeDetection> pDollar =
         createStructuredEdgeDetection(modelFilename);
     pDollar->detectEdges(image, edges);
 
-    if ( outFilename == "" )
+    if ( outFilename.size() == 0 )
     {
-        cv::namedWindow("edges", 1);
-        cv::imshow("edges", edges);
-
-        cv::waitKey(0);
+        namedWindow("edges", 1);
+        imshow("edges", edges);
+        waitKey(0);
     }
     else
-        cv::imwrite(outFilename, 255*edges);
+        imwrite(outFilename, 255*edges);
 
     return 0;
 }

modules/ximgproc/src/structured_edge_detection.cpp

@@ -235,6 +235,7 @@ static void gradientHist(const cv::Mat &src, cv::Mat &magnitude, cv::Mat &histog
     magnitude /= imsmooth( magnitude, gnrmRad )
         + 0.01*cv::Mat::ones( magnitude.size(), magnitude.type() );
 
+    int pHistSize = histogram.cols*histogram.channels() - 1;
     for (int i = 0; i < phase.rows; ++i)
     {
         const float *pPhase = phase.ptr<float>(i);
@@ -243,7 +244,11 @@ static void gradientHist(const cv::Mat &src, cv::Mat &magnitude, cv::Mat &histog
         float *pHist = histogram.ptr<float>(i/pSize);
 
         for (int j = 0; j < phase.cols; ++j)
-            pHist[cvRound((j/pSize + pPhase[j])*nBins)] += pMagn[j] / CV_SQR(pSize);
+        {
+            int index  = cvRound((j/pSize + pPhase[j])*nBins);
+            index = std::max(0, std::min(index, pHistSize));
+            pHist[index] += pMagn[j] / CV_SQR(pSize);
+        }
     }
 }