/*# proc: pixelcnt8 - counts the number of black pixels in a binary character# proc:            stream, one byte per pixel, faster than pixelcnt.# proc: subpixelcnt8 - counts the number of black pixels in the specified subimage of# proc:                a binary character stream, one byte per pixel.# proc: pixelcnt - counts the number of black pixels in a binary character# proc:            image, one byte per pixel, same result as pixelcnt8.# proc: shift_row - takes a row of character pixels and shifts them left or# proc:             right by a given number of pixel into an output row.# proc: left_pix - locates the first nonzero pixel left-to-right in a given# proc:            row of character pixels and returns -1 if no pixel is found.# proc: char_top - locates the first row of pixels top-to-bottom in a character# proc:            image that contains a nonzero pixel and returns -1 if no# proc:            row is found.# proc: char_bottom - locates the first row of pixels bottom-to-top in a# proc:               character image that contains a nonzero pixel and# proc:               returns -1 if no row is found.*/#include <stddef.h>/*******************************************************************/int pixelcnt8(inp, n)unsigned char *inp; int n;{int i, b;unsigned char t, *ptr, *str;    /* temporarily set last pixel to 1 so that we know which inner	*/   /* loop must test for image completion: the other one does no test!	*/    /* loops n-1 times then checks the last stop pixel			*/   /* subtle but gives over 10 sd20 images 27->22 secs = 5secs gain	*/    t = inp[n-1]; inp[n-1] = 1;   for ( i = n-1, ptr = inp, b = 0 ; i ; )   {      for ( str = ptr ; !(*ptr)      ; ptr++ );         /* skip white	*/      i -= (ptr-str);                                   /* num skiped	*/       for ( str = ptr ;  (*ptr) && i ; ptr++, i-- );    /* count black	*/       b += (ptr-str);   }   if (t) b++;   inp[n-1] = t;	/* consider the last one, and restore	*/   return b;}/*******************************************************************/subpixelcnt8(cdata, w, h, sx, sy, sw, sh)unsigned char *cdata;int w, h, sx, sy, sw, sh;{   int count, x, y;   int xlim, ylim;   unsigned char *sptr, *pptr;   if((sx < 0) || (sx >= w))      fatalerr("subpixelcnt8",               "subimage x coordinate exceeds image dimensions", NULL);   if((sy < 0) || (sy >= h))      fatalerr("subpixelcnt8",               "subimage y coordinate exceeds image dimensions", NULL);   if((xlim = sx+sw) > w)      fatalerr("subpixelcnt8",               "subimage w exceeds image width", NULL);   if((ylim = sy+sh) > h)      fatalerr("subpixelcnt8",               "subimage h exceeds image height", NULL);   count = 0;   sptr = cdata + (sy * w) + sx;   for(y = sy; y < ylim; y++){      pptr = sptr;      for(x = sx; x < xlim; x++){         if(*pptr)            count++;         pptr++;      }      sptr+=w;   }   return(count);}/*******************************************************************/pixelcnt(cdata, w, h)unsigned char *cdata; int w, h;{   static int ow = -1, oh = -1, olen;   if((ow != w) || (oh != h)){      olen = w*h;      ow = w;      oh = h;   }   return pixelcnt8(cdata, olen);}/*******************************************************************/shift_row(irow, orow, w, sval)unsigned char *irow, *orow;int w, sval;{   if(sval == 0){      memcpy(orow, irow, w);      return;   }   if(abs(sval) >= w){      memset(orow, 0, w);      return;   }   if(sval > 0){      memset(orow, 0, w);      memcpy(orow + sval, irow, w - sval);      return;   }   if(sval < 0){      memset(orow, 0, w);      memcpy(orow, irow - sval, w + sval);      return;   }}/*************************************************************************/left_pix(row, w)unsigned char *row;int w;{   int i;   unsigned char *rptr;   rptr = row;   for(i = 0; i < w; i++){      if(*rptr != 0)         return(i);      else         rptr++;   }   return(-1);}/*************************************************************************/char_top(cdata, w, h)unsigned char *cdata;int w, h;{   int r, c;   unsigned char *cptr;   cptr = cdata;   for(r = 0; r < h; r++){      for(c = 0; c < w; c++){         if(*cptr != 0)            return(r);         else            cptr++;      }   }   return(-1);}/*************************************************************************/char_bottom(cdata, w, h)unsigned char *cdata;int w, h;{   int len, r, c;   unsigned char *cptr;   len = w * h;   cptr = cdata + len - 1;   for(r = h-1; r >= 0; r--){      for(c = 0; c < w; c++){         if(*cptr != 0)            return(r);         else            cptr--;      }   }   return(-1);}