#include <math.h>

void sobelfunc(int** pic, int** edges, int** tempx, int** tempy){

        int maskx[3][3] = {{-1,0,1},{-2,0,2},{-1,0,1}};
        int masky[3][3] = {{1,2,1},{0,0,0},{-1,-2,-1}};
        int maxival;


        
 
        int i,j,p,q,mr,sum1,sum2;
        double threshold;
         

        mr = 1;


        for (i=mr;i<numRows-mr;i++)
        { for (j=mr;j<numCols-mr;j++)
          {
             sum1 = 0;
             sum2 = 0;
             for (p=-mr;p<=mr;p++)
             {
                for (q=-mr;q<=mr;q++)
                {
                   sum1 += pic[i+p][j+q] * maskx[p+mr][q+mr];
                   sum2 += pic[i+p][j+q] * masky[p+mr][q+mr];
                }
             }
             tempx[i][j] = sum1;
             tempy[i][j] = sum2;
          }
        }

        maxival = 0;
        for (i=mr;i<numRows-mr;i++)
        { for (j=mr;j<numCols-mr;j++)
          {
             edges[i][j]=(int) (sqrt((double)((tempx[i][j]*tempx[i][j]) +
                                      (tempy[i][j]*tempy[i][j]))));
             if (edges[i][j] > maxival)
                maxival = edges[i][j];

           }
        }



        for (i=0;i<numRows;i++)
          { for (j=0;j<numCols;j++)
            {
             edges[i][j] = ((edges[i][j]*1.0) / maxival) * 255;            
             
            }
          }
}