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grayscal.c

Go to the documentation of this file.

#include        "sadie.h"

/*-Copyright Information------------------------------------------------------*/
/* Copyright (c) 1988 by the University of Arizona Digital Image Analysis Lab */
/*----------------------------------------------------------------------------*/
/*-General Information--------------------------------------------------------*/
/*                                                                            */
/*   This function generates a horizontal grayscale pattern.                  */
/*                                                                            */
/*----------------------------------------------------------------------------*/
/*-Interface Information------------------------------------------------------*/
void
GRAYSCAL (short nlin,           /*  I   Number of lines in the output image.                  */
          short npix,           /*  I   Number of pixels/line in the output image.            */
          short nlev,           /*  I   Number of graylevels in the output image.             */
          PIXEL gmin,           /*  I   Minimum graylevel.                                    */
          PIXEL gmax,           /*  I   Maximum graylevel.                                    */
          IMAGE ** out          /*  O   Address of a pointer to the output image.             */
/*----------------------------------------------------------------------------*/
  )
{
  register short j, k;
  char msg[SLEN];
  double inc =
    (nlev <= 1 ? 0.0 : (double) (gmax - gmin) / (double) (nlev - 1));

  if (TIMES)
    TIMING (T_GRAYSCAL);
  if (NAMES)
    {
      MESSAGE ('I', "");
      MESSAGE ('I', "GRAYSCAL");
      MESSAGE ('I', "");
      sprintf (msg, " Image size: lines:     %d", nlin);
      MESSAGE ('I', msg);
      sprintf (msg, "             pixels:    %d", npix);
      MESSAGE ('I', msg);
      sprintf (msg, " Minimum graylevel:   %12.4e", gmin);
      MESSAGE ('I', msg);
      sprintf (msg, " Maximum graylevel:   %12.4e", gmax);
      MESSAGE ('I', msg);
      sprintf (msg, " Number of graylevels:  %d", nlev);
      MESSAGE ('I', msg);
      MESSAGE ('I', " ...............");
    }

  /* check input */
  if (nlin <= 0)
    {
      MESSAGE ('E', " Number of lines must be greater than zero.");
      goto the_end;
    }
  else if (npix <= 0)
    {
      MESSAGE ('E', " Number of pixels/line must be greater than zero.");
      goto the_end;
    }
  else if (nlev <= 0)
    {
      MESSAGE ('E', " Number of graylevels must be greater than zero.");
      goto the_end;
    }
  else if (nlev > npix)
    {
      MESSAGE ('E',
               " Number of graylevels must be less than or equal to number of pixels/line.");
      goto the_end;
    }
  else if (gmin > gmax)
    {
      MESSAGE ('E',
               " Minimum graylevel value must be less than or equal to maximum graylevel value.");
      goto the_end;
    }

  /* create image of appropriate size */
  if (!CHECKIMG (*out))
    GETMEM (1, nlin, npix, out);
  if (!*out)
    goto the_end;

  /* create grayscale */
  for (k = 0; k < npix; k++)
    {
      (*out)->data[0][0][k] =
        (PIXEL) ((double) gmin +
                 (double) ((long) k * (long) nlev / (long) npix) * inc);
    }
  for (j = 1; j < nlin; j++)
    {
      for (k = 0; k < npix; k++)
        {
          (*out)->data[0][j][k] = (*out)->data[0][0][k];
        }
    }
  (*out)->gmin = gmin;
  (*out)->gmax = gmax;

the_end:
  if (TIMES)
    TIMING (T_EXIT);
}

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