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subsampl.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 extracts a subimage from an image.                         */
/*                                                                            */
/*----------------------------------------------------------------------------*/
/*-Interface Information------------------------------------------------------*/
void
SUBSAMPL (IMAGE * in,           /*  I   Pointer to the input image.                           */
          short ibgn,           /*  I   Number of the first band to be sampled.               */
          short jbgn,           /*  I   Number of the first line to be sampled.               */
          short kbgn,           /*  I   Number of the first pixel to be sampled.              */
          short iinc,           /*  I   Band increment during sampling.                       */
          short jinc,           /*  I   Line increment during sampling.                       */
          short kinc,           /*  I   Pixel increment during sampling.                      */
          short isize,          /*  I   Number of bands to be spanned.                        */
          short jsize,          /*  I   Number of lines to be spanned.                        */
          short ksize,          /*  I   Number of pixels/line to be spanned.                  */
          IMAGE ** out          /*  O   Address of a pointer to the output image.             */
/*----------------------------------------------------------------------------*/
  )
{
  register short i, j, k, l, m, n, nbnd, nlin, npix;
  char msg[SLEN];

  if (TIMES)
    TIMING (T_SUBSAMPL);
  if (NAMES)
    {
      MESSAGE ('I', "");
      MESSAGE ('I', "SUBSAMPL");
      MESSAGE ('I', "");
      sprintf (msg, " Input image:                                %s",
               in->text);
      MESSAGE ('I', msg);
      sprintf (msg, " From:                band, line, pixel:     %d, %d, %d",
               ibgn + 1, jbgn + 1, kbgn + 1);
      MESSAGE ('I', msg);
      sprintf (msg, " To:                  band, line, pixel:     %d, %d, %d",
               isize + ibgn, jsize + jbgn, ksize + kbgn);
      MESSAGE ('I', msg);
      sprintf (msg, " Subsample increment: bands, lines, pixels:  %d, %d, %d",
               iinc, jinc, kinc);
      MESSAGE ('I', msg);
      MESSAGE ('I', " ...............");
    }

  /* check input */
  if (!CHECKIMG (in))
    {
      MESSAGE ('E', " Can't identify image.");
      goto the_end;
    }
  else if (0 > ibgn || ibgn + isize > in->nbnd)
    {
      MESSAGE ('E',
               " Image to be sampled must be located completely inside input image in the band dimension.");
      goto the_end;
    }
  else if (0 > jbgn || jbgn + jsize > in->nlin)
    {
      MESSAGE ('E',
               " Image to be sampled must be located completely inside input image in the line dimension.");
      goto the_end;
    }
  else if (0 > kbgn || kbgn + ksize > in->npix)
    {
      MESSAGE ('E',
               " Image to be sampled must be located completely inside input image in the pixel dimension.");
      goto the_end;
    }
  else if (iinc <= 0)
    {
      MESSAGE ('E', " Band subsample increment must be greater than zero.");
      goto the_end;
    }
  else if (jinc <= 0)
    {
      MESSAGE ('E', " Line subsample increment must be greater than zero.");
      goto the_end;
    }
  else if (kinc <= 0)
    {
      MESSAGE ('E', " Pixel subsample increment must be greater than zero.");
      goto the_end;
    }
  else if (isize <= 0)
    {
      MESSAGE ('E',
               " Number of bands to be spanned must be greater than zero.");
      goto the_end;
    }
  else if (jsize <= 0)
    {
      MESSAGE ('E',
               " Number of lines to be spanned must be greater than zero.");
      goto the_end;
    }
  else if (ksize <= 0)
    {
      MESSAGE ('E',
               " Number of pixels/line to be spanned must be greater than zero.");
      goto the_end;
    }

  /* create image of appropriate size */
  nbnd = (short) ceil ((double) isize / (double) iinc);
  nlin = (short) ceil ((double) jsize / (double) jinc);
  npix = (short) ceil ((double) ksize / (double) kinc);
  if (!CHECKIMG (*out))
    GETMEM (nbnd, nlin, npix, out);
  if (!*out)
    goto the_end;

  /* extract subimage */
  for (i = 0, l = ibgn; i < nbnd && l < in->nbnd; i += 1, l += iinc)
    {
      for (j = 0, m = jbgn; j < nlin && m < in->nlin; j += 1, m += jinc)
        {
          for (k = 0, n = kbgn; k < npix && n < in->npix; k += 1, n += kinc)
            {
              (*out)->data[i][j][k] = in->data[l][m][n];
            }
        }
    }

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

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