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img2pnm.c

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#include "sadie.h"

#define UCHAR(c) ((unsigned char) (c))

/*
 * The maximum amount of memory to allocate for data read from the
 * file.  If we need more than this, we do it in pieces.
 */

#define MAX_MEMORY      10000   /* don't allocate > 10KB */

/*
 * Define PGM and PNM, i.e. gray images and color images.
 */

#define PGM 1
#define PPM 2

/*-Copyright Information------------------------------------------------------*/
/* Copyright (c) 1988 by the University of Arizona Digital Image Analysis Lab */
/*----------------------------------------------------------------------------*/
/*-General Information--------------------------------------------------------*/
/*                                                                            */
/*   This function writes a SADIE image from main memory to a PNM file.       */
/*                                                                            */
/*----------------------------------------------------------------------------*/
/*-Interface Information------------------------------------------------------*/
void
IMG2PNM (in, name)
     IMAGE *in;                 /*  I   Pointer to the image.                                 */
     char *name;                /*  I   String, containing the name of the disk file.         */
/*----------------------------------------------------------------------------*/
{
  int i, j, k;
  char msg[SLEN];
  FILE *fp = NULL;
  int nBytes, nbit = 8;
  unsigned char *pixelPtr = NULL, *data = NULL;
  char header[30];
  int count;
  PIXEL factor;
  char type[5];
  int nbnd;

  /* open image file */
  if (!(fp = fopen (name, "w")))
    {
      sprintf (msg, " Can't open file %s.", name);
      MESSAGE ('E', msg);
      goto the_end;
    }

  if (!CHECKIMG (in))
    {
      MESSAGE ('E', " Can't identify image.");
      goto the_end;
    }

  if (NAMES)
    {
      MESSAGE ('I', "");
      MESSAGE ('I', "IMG2PNM");
      MESSAGE ('I', "");
      sprintf (msg, " Input image:               %s", in->text);
      MESSAGE ('I', msg);
      sprintf (msg, " Output disk file:          %s", name);
      MESSAGE ('I', msg);
      sprintf (msg, " Output format:             %d-bit PNM", nbit);
      MESSAGE ('I', msg);
      MESSAGE ('I', " ...............");
    }

  RANGE (in);
  if (in->gmax > in->gmin)
    {
      factor = (PIXEL) 255.0 / (in->gmax - in->gmin);
    }

  if (in->nbnd == 3)
    {
      nbnd = 3;
      sprintf (type, "P6");
    }
  else
    {
      nbnd = 1;
      sprintf (type, "P5");
    }

  sprintf (header, "%s\n%d %d\n255\n", type, in->npix, in->nlin);
  nBytes = strlen (header);
  count = fwrite (header, 1, nBytes, fp);
  if (count != nBytes)
    {
      MESSAGE ('E', "Can't write header to file.");
      goto the_end;
    }

  nBytes = in->npix * nbnd;
  pixelPtr = (unsigned char *) malloc ((unsigned) nBytes);
  if (!pixelPtr)
    {
      MESSAGE ('E', "Could not allocate memory to write image.");
      goto the_end;
    }

  for (j = 0; j < in->nlin; j++)
    {
      data = pixelPtr;

      for (k = 0; k < in->npix; k++)
        {
          for (i = 0; i < nbnd; i++)
            {
              *data++ = (unsigned char) rnd (in->data[i][j][k] * factor);
            }
        }

      count = fwrite (pixelPtr, 1, nBytes, fp);
      if (count != nBytes)
        {
          sprintf (msg, "Error writing PNM image data to file");
          MESSAGE ('E', msg);
          goto the_end;
        }
    }

the_end:

  if (pixelPtr)
    free (pixelPtr);

  if (fp)
    {
      if (fclose (fp))
        {
          sprintf (msg, " Can't close file %s.", name);
          MESSAGE ('W', msg);
        }
    }

}

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