#include <stdio.h>
#include <stdlib.h>
#include <libio.h>

int main(void)
{
/*  Define the file pointer and variable types */

  FILE *ifp,*ifo,*ifpc,*ifoc;
  int nc,nr,nrows,ncolumns;
  signed short *ptr;
  signed short i,j;
  char *wptr, out;

nrows=896;
ncolumns=896;

/*  Open the file read only binary */

ifp = fopen("c5decA92", "rb");
ifo = fopen("c5decA92.bin", "wb");
ifpc = fopen("c5decC92", "rb");
ifoc = fopen("c5decC92.bin", "wb");

/* Apparently the file has an initial offset of one */

fseek(ifp,+1, SEEK_CUR); 
fseek(ifpc,+1, SEEK_CUR); 

/*  Begin the loops that will cover the rows and 
	columns of the data file.... */

for (nc=1; nc <= ncolumns;++nc){
for (nr=1; nr <= nrows;++nr){


  ptr=&i;
  wptr=&out;
  fread(ptr, 2, 1, ifp);
  if (i <= 513 ) out=1;
  if (i <= 1 ) out=255;
  if (i > 513) out=((i-512)/2);
  fwrite(wptr, 1, 1, ifo);

  ptr=&i;
  wptr=&out;
  fread(ptr, 2, 1, ifpc);
  if (i <= 513 ) out=1;
  if (i <= 1 ) out=255;
  if (i > 513) out=((i-512)/2);
  fwrite(wptr, 1, 1, ifoc);


/* The for loops end here */
}}

close(ifp); 
close(ifo); 
close(ifpc); 
close(ifoc); 
exit(0);
}