void ReadImage(char fname[], int ***fimage, int& M, int& N, int& Q)
{
 int i, j;
 unsigned char *image;
 char header [100], *ptr;
 ifstream ifp;

 ifp.open(fname, ios::in); 

 if (!ifp) {
   cout << "Can't read image: " << fname << endl;
   exit(1);
 }

 // read header

 ifp.getline(header,100,'\n');
 if ( (header[0]!=80) ||    /* 'P' */
      (header[1]!=53) ) {   /* '5' */
      cout << "Image " << fname << " is not PGM" << endl;
      exit(1);
 }

 ifp.getline(header,100,'\n');
 while(header[0]=='#')
   ifp.getline(header,100,'\n');

 M=strtol(header,&ptr,0);
 N=atoi(ptr);

 ifp.getline(header,100,'\n');

 Q=strtol(header,&ptr,0);

 image = (unsigned char *) new unsigned char [M*N];

 *fimage = new int* [N];
 for(i=0; i<N; i++)
   (*fimage)[i] = new int[M];

 ifp.read( reinterpret_cast<char *>(image), (M*N)*sizeof(unsigned char));

 if (ifp.fail()) {
   cout << "Image " << fname << " has wrong size" << endl;
   exit(1);
 }

 ifp.close();

 //
 // Convert the unsigned characters to integers
 //

 for(i=0; i<N; i++)
   for(j=0; j<M; j++)
     (*fimage)[i][j]=(int)image[i*M+j];
}