/* mwcommandname = {llmap};version={"1.6"};author={"Jacques Froment, Frederic Guichard"};function={"Map the level lines of an image"};usage = {'s':[level_step=20]->ls [1,255] "gray level step (default:20)",'t'->tmap "code the type of border",image -> input "image input",level_lines <- output "level lines of input"};*//*---------------------------------------------------------------------- v1.6: return result (L.Moisan)----------------------------------------------------------------------*/#include <stdio.h>#include <math.h>#include "mw.h"/* Type of borders */#define VOID 255#define LEFT 200#define UP   100#define BOTH 0Cimage llmap(ls,tmap,input, output)     short *ls;char *tmap;Cimage input;Cimage output;{  register int l;  register unsigned char *in,*out;  int dx,dy,size,beg;  unsigned char step,U,L,C;    step = (unsigned char) *ls;  dy= input->nrow;  dx= input->ncol;  size=dx*dy;    output=mw_change_cimage(output,dy,dx);  if (!output) mwerror(FATAL,1,"Not enough memory.\n");  mw_clear_cimage(output,255);    beg=dx;  if (!tmap)    { /* Every borders are coded as value 0 */      for (l=beg, in=input->gray+beg, out = output->gray+beg; 	   l<size; 	   l++,in++,out++)	if ( ((*(in-1)/step)!=(*in/step)) || ((*(in-dx)/step)!=(*in/step)) )	  *out=0;	else	  *out=255;    }  else    {      for (l=beg, in=input->gray+beg, out = output->gray+beg; 	   l<size; 	   l++,in++,out++)	{	  C=*in/step;	  L=*(in-1)/step;	  U=*(in-dx)/step;	  if ((L==C) && (U==C)) *out=VOID;	  else	    if ((L!=C) && (U!=C)) *out=BOTH;	    else	      if (L!=C) *out=LEFT;	      else		*out=UP;	}    }  return(output);}