/*--------------------------- Commande MegaWave -----------------------------*//* mwcommand  name = {resthline};  version = {"1.0"};  author = {"Lionel Moisan"};  function = {"Restore infrared-type images by suppressing horizontal line effects"};  usage = {            input -> u      "input image",            output <- v     "output image"          };*//*-- MegaWave - Copyright (C) 1994 Jacques Froment. All Rights Reserved. --*/#include <stdio.h>/* Include always the MegaWave2 Library */#include "mw.h"#define ABS(x) ((x)>0?(x):(-(x)))/***** Minimize the total variation between two arrays ****/int minimize_tv(a,b,n)unsigned char *a,*b;int n;{    int d,dmin,i,tv,tvmin,diff;    tvmin = 256*n; dmin = 0;    for (d=-80; d<=80; d++) {	tv = 0;	for (i=0;i<n;i++) {	    diff = d+b[i]-a[i];	    tv+=ABS(diff);	}	if (tv<tvmin) {	    dmin = d;	    tvmin=tv;	}    }    mwdebug("tvmin=%d, dmin=%d\n",tvmin,dmin);    return dmin;}/*** Main function : Suppress horizontal line artefacts by minimizing *** ***      the total variation under horizontal offsets correction     ***/void resthline(u,v)Cimage u,v;{  int x,y,adr,dx,dy,cofs,tofs,*ofs,new;  /* Allocate memory */  dx=u->ncol; dy=u->nrow;  v = mw_change_cimage(v,dy,dx);  ofs = (int *)malloc(dy*sizeof(int));  if (!v || !ofs) mwerror(FATAL,1,"Not enough memory.");  /* Compute offsets between line pairs */  cofs = 0;  tofs = 0;  for (y=0;y<dy-1;y++) {      adr = y*dx;      ofs[y] = minimize_tv(u->gray+adr,u->gray+adr+dx,dx);      cofs += ofs[y];      tofs += cofs;  }  cofs = -tofs/dy; /* correction for mean adjustment */  mwdebug("total offset = %d\n",cofs);  /* Process image */  for (y=0;y<dy;y++) {      adr = y*dx;      for (x=0;x<dx;x++) {	  new = u->gray[adr+x]+cofs;	  v->gray[adr+x] = (new<0?0:new>255?255:new);      }      cofs += ofs[y];  }}