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I am trying to implement a median filter(for practice). The program showed the output image correctly but it ended with a segmentation fault. The following error occurred just before exiting main(){}

Program received signal SIGSEGV, Segmentation fault. 0x00007ffff78bf789 in cv::ImageCodecInitializer::~ImageCodecInitializer() () from /usr/local/lib/libopencv_imgcodecs.so.3.2

//mainFile.cpp
  1 #include <opencv2/highgui/highgui.hpp>
  2 #include <opencv2/core/core.hpp>
  3 #include "lowp.h"
  4 //#include <stdlib.h>
  5 using namespace cv;
  6 
  7 void medFilter(Mat &, Mat &, int);
  8 int main(){
  9         Mat img = imread("home.jpg",1);
 10         Mat out;
 11         medFilter(img,out,7);
 12         namedWindow("Example");
 13         imshow("Example", out);
 14         waitKey(0);
 15         destroyWindow("Example");
 16 }
 17 


    //lowp.h
     33  void medFilter(Mat &img, Mat &out, int size){
     34         Mat low(img.rows, img.cols, img.type());
     35         int r = img.rows;
     36         int c = img.cols;
     37         const int ch = img.channels();
     38         int hist[255];
     39         int w = 0;
     40         int *win;
     41         win = new int(size*size);
     42         for(int h = 0; h<255; h++){
     43                 hist[h] = 0;
     44         }
     45         for(int i = 0; i<r; i++){
     46                 for(int j = 0; j<c; j++){
     47                         for(int chi = 0; chi < ch; chi++){
     48                                 if(i>=size/2 && i<r-size/2 && j>=size/2 && j<c-size/2){
     49                                         for(int u = -size/2 ; u<=size/2; u++){
     50                                                 for(int v = -size/2; v<=size/2; v++){
     51                                                         win[w] = *(img.ptr<uchar>(i + u) + (j + v)*ch + chi);
     52                                                         w++;
     53                                                 }
     54                                         }
     55                                         w = 0;
     56                                         *(low.ptr<uchar>(i) + j*ch + chi) = getMedian(win, hist, (size*size));
     57                                 }else{
     58                                         *(low.ptr<uchar>(i) + j*ch + chi) = *(img.ptr<uchar>(i) + j*ch + chi);
     59                                 }
     60                         }
     61                 }
     62         }
     63         out = low;
     64 }

 66       uchar  getMedian(int* w, int* hist, int size){
 67         uchar h;
 68         for(int i = 0; i<size; i++){
 69                 hist[w[i]] ++;
 70         }
 71         int sum = 0;
 72         for(h = 0; h<255; h++){
 73                 sum += hist[h];
 74                 if(sum>size/2) break;
 75         }
 76         for(int i = 0; i<size; i++){
 77                 hist[w[i]] = 0;
 78         }
 79         return h;
 80 }

I am trying to implement a median filter(for practice). The program showed the output image correctly but it ended with a segmentation fault. The following error occurred just before exiting main(){}

Program received signal SIGSEGV, Segmentation fault. 0x00007ffff78bf789 in cv::ImageCodecInitializer::~ImageCodecInitializer() () from /usr/local/lib/libopencv_imgcodecs.so.3.2

//mainFile.cpp
  1 #include <opencv2/highgui/highgui.hpp>
  2 <opencv2/highgui/highgui.h
 #include <opencv2/core/core.hpp>
  3 #include "lowp.h"
  4 //#include <stdlib.h>
  5 using namespace cv;
  6   7 void medFilter(Mat &, Mat &, int);
  8 int main(){
  9         Mat img = imread("home.jpg",1);
 10         Mat out;
 11         medFilter(img,out,7);
 12         namedWindow("Example");
 13         imshow("Example", out);
 14         waitKey(0);
 15         destroyWindow("Example");
 16 }
 17  }



    //lowp.h
     33  void medFilter(Mat &img, Mat &out, int size){
     34         Mat low(img.rows, img.cols, img.type());
     35         int r = img.rows;
     36         int c = img.cols;
     37         const int ch = img.channels();
     38         int hist[255];
     39         int w = 0;
     40         int *win;
     41         win = new int(size*size);
     42         for(int h = 0; h<255; h++){
     43                 hist[h] = 0;
     44         }
     45      }
          for(int i = 0; i<r; i++){
     46                 for(int j = 0; j<c; j++){
     47                         for(int chi = 0; chi < ch; chi++){
     48                                 if(i>=size/2 && i<r-size/2 && j>=size/2 && j<c-size/2){
     49                                         for(int u = -size/2 ; u<=size/2; u++){
     50                                                 for(int v = -size/2; v<=size/2; v++){
     51                                                         win[w] = *(img.ptr<uchar>(i + u) + (j + v)*ch + chi);
     52                                                         w++;
     53                                                 }
     54                                         }
     55                                               }
                                           }
                                          w = 0;
     56                                         *(low.ptr<uchar>(i) + j*ch + chi) = getMedian(win, hist, (size*size));
     57                                 }else{
     58                                         *(low.ptr<uchar>(i) + j*ch + chi) = *(img.ptr<uchar>(i) + j*ch + chi);
     59                                 }
     60                         }
     61                 }
     62         }
     63                              }
                         }
                 }
          }
          out = low;
     64 }

 66       uchar  getMedian(int* w, int* hist, int size){
 67         uchar h;
 68         for(int i = 0; i<size; i++){
 69                 hist[w[i]] ++;
 70         }
 71         }
          int sum = 0;
 72          for(h = 0; h<255; h++){
 73                  sum += hist[h];
 74                  if(sum>size/2) break;
 75         }
 76          }
         for(int i = 0; i<size; i++){
 77                  hist[w[i]] = 0;
 78         }
 79         }
         return h;
 80  }

I am trying to implement a median filter(for practice). The program showed the output image correctly but it ended with a segmentation fault. The following error occurred just before exiting main(){}

Program received signal SIGSEGV, Segmentation fault. 0x00007ffff78bf789 in cv::ImageCodecInitializer::~ImageCodecInitializer() () from /usr/local/lib/libopencv_imgcodecs.so.3.2

//mainFile.cpp
 #include <opencv2/highgui/highgui.h
 #include <opencv2/core/core.hpp>
 #include "lowp.h"
 //#include <stdlib.h>
 using namespace cv;

 void medFilter(Mat &, Mat &, int);
 int main(){
 Mat img = imread("home.jpg",1);
 Mat out;
 medFilter(img,out,7);
 namedWindow("Example");
 imshow("Example", out);
 waitKey(0);
 destroyWindow("Example");
  }



    //lowp.h
 void medFilter(Mat &img, Mat &out, int size){
 Mat low(img.rows, img.cols, img.type());
 int r = img.rows;
  int c = img.cols;
 const int ch = img.channels();
 int hist[255];
 int w = 0;
 int *win;
 win = new int(size*size);
  for(int h = 0; h<255; h++){
                  hist[h] = 0;
          }
          for(int i = 0; i<r; i++){
                   for(int j = 0; j<c; j++){
                        for(int chi = 0; chi < ch; chi++){
                                  if(i>=size/2 && i<r-size/2 && j>=size/2 && j<c-size/2){
                                           for(int u = -size/2 ; u<=size/2; u++){
                                                 for(int v = -size/2; v<=size/2; v++){
                                                          win[w] = *(img.ptr<uchar>(i + u) + (j + v)*ch + chi);
                                                          w++;
                                                   }
                                           }
                                          w = 0;
                                         *(low.ptr<uchar>(i) + j*ch + chi) = getMedian(win, hist, (size*size));
                                  }else{
                                         *(low.ptr<uchar>(i) + j*ch + chi) = *(img.ptr<uchar>(i) + j*ch + chi);
                                  }
                         }
                 }
          }
          out = low;
  }

   uchar  getMedian(int* w, int* hist, int size){
        uchar h;
        for(int i = 0; i<size; i++){
              hist[w[i]] ++;
         }
          int sum = 0;
          for(h = 0; h<255; h++){
                  sum += hist[h];
                  if(sum>size/2) break;
          }
         for(int i = 0; i<size; i++){
                  hist[w[i]] = 0;
         }
         return h;
  }

I am trying to implement a median filter(for practice). The program showed the output image correctly but it ended with a segmentation fault. The following error occurred just before exiting main(){}

Program received signal SIGSEGV, Segmentation fault. 0x00007ffff78bf789 in cv::ImageCodecInitializer::~ImageCodecInitializer() () from /usr/local/lib/libopencv_imgcodecs.so.3.2

//mainFile.cpp
 #include <opencv2/highgui/highgui.h
 #include <opencv2/core/core.hpp>
 #include "lowp.h"
 //#include <stdlib.h>
 using namespace cv;

 void medFilter(Mat &, Mat &, int);
 int main(){
 Mat img = imread("home.jpg",1);
 Mat out;
 medFilter(img,out,7);
 namedWindow("Example");
 imshow("Example", out);
 waitKey(0);
 destroyWindow("Example");
  }



    //lowp.h
 void medFilter(Mat &img, Mat &out, int size){
  Mat low(img.rows, img.cols, img.type());
  int r = img.rows;
   int c = img.cols;
  const int ch = img.channels();
  int hist[255];
  int w = 0;
  int *win;
  win = new int(size*size);
   for(int h = 0; h<255; h++){
                  hist[h] = 0;
          }
    }
      for(int i = 0; i<r; i++){
                   for(int j = 0; j<c; j++){
                        for(int chi = 0; chi < ch; chi++){
                                  if(i>=size/2 && i<r-size/2 && j>=size/2 && j<c-size/2){
                                           for(int u = -size/2 ; u<=size/2; u++){
                                                 for(int v = -size/2; v<=size/2; v++){
                                                          win[w] = *(img.ptr<uchar>(i + u) + (j + v)*ch + chi);
                                                          w++;
                                                   }
                                           }
                                          w = 0;
                                         *(low.ptr<uchar>(i) + j*ch + chi) = getMedian(win, hist, (size*size));
                                  }else{
                                         *(low.ptr<uchar>(i) + j*ch + chi) = *(img.ptr<uchar>(i) + j*ch + chi);
                                  }
                         }
                 }
          }
          out = low;
  }

   uchar  getMedian(int* w, int* hist, int size){
        uchar h;
        for(int i = 0; i<size; i++){
              hist[w[i]] ++;
         }
          int sum = 0;
          for(h = 0; h<255; h++){
                  sum += hist[h];
                  if(sum>size/2) break;
          }
         for(int i = 0; i<size; i++){
                  hist[w[i]] = 0;
         }
         return h;
  }

I am trying to implement a median filter(for practice). The program showed the output image correctly but it ended with a segmentation fault. The following error occurred just before exiting main(){}

Program received signal SIGSEGV, Segmentation fault. 0x00007ffff78bf789 in cv::ImageCodecInitializer::~ImageCodecInitializer() () from /usr/local/lib/libopencv_imgcodecs.so.3.2

//mainFile.cpp
 #include <opencv2/highgui/highgui.h
 #include <opencv2/core/core.hpp>
 #include "lowp.h"
 //#include <stdlib.h>
 using namespace cv;

 void medFilter(Mat &, Mat &, int);
 int main(){
 Mat img = imread("home.jpg",1);
 Mat out;
 medFilter(img,out,7);
 namedWindow("Example");
 imshow("Example", out);
 waitKey(0);
 destroyWindow("Example");
  }



    //lowp.h
 void medFilter(Mat &img, Mat &out, int size){
      Mat low(img.rows, img.cols, img.type());
      int r = img.rows;
      int c = img.cols;
      const int ch = img.channels();
      int hist[255];
hist[256];   //changed from int hist[255] -- as correctly suggested by LBerger
      int w = 0;
      int *win;
      win = new int(size*size);
      for(int h = 0; h<255; h++){
                  hist[h] = 0;
      }
      for(int i = 0; i<r; i++){
                   for(int j = 0; j<c; j++){
                        for(int chi = 0; chi < ch; chi++){
                                  if(i>=size/2 && i<r-size/2 && j>=size/2 && j<c-size/2){
                                           for(int u = -size/2 ; u<=size/2; u++){
                                                 for(int v = -size/2; v<=size/2; v++){
                                                          win[w] = *(img.ptr<uchar>(i + u) + (j + v)*ch + chi);
                                                          w++;
                                                   }
                                           }
                                          w = 0;
                                         *(low.ptr<uchar>(i) + j*ch + chi) = getMedian(win, hist, (size*size));
                                  }else{
                                         *(low.ptr<uchar>(i) + j*ch + chi) = *(img.ptr<uchar>(i) + j*ch + chi);
                                  }
                         }
                 }
          }
          out = low;
  }

   uchar  getMedian(int* w, int* hist, int size){
        uchar h;
        for(int i = 0; i<size; i++){
              hist[w[i]] ++;
         }
          int sum = 0;
          for(h = 0; h<255; h++){
                  sum += hist[h];
                  if(sum>size/2) break;
          }
         for(int i = 0; i<size; i++){
                  hist[w[i]] = 0;
         }
         return h;
  }