imutil.h

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/*
Copyright (C) 2006 Pedro Felzenszwalb

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
*/

/* some image utilities */

#pragma once

#include "image.h"
#include "misc.h"

namespace distance_transform
{

  /* compute minimum and maximum value in an image */
  template <class T>
  void min_max(image<T> *im, T *ret_min, T *ret_max) {
    int width = im->width();
    int height = im->height();
    
    T min = imRef(im, 0, 0);
    T max = imRef(im, 0, 0);
    for (int y = 0; y < height; y++) {
      for (int x = 0; x < width; x++) {
        T val = imRef(im, x, y);
        if (min > val)
    min = val;
        if (max < val)
    max = val;
      }
    }

    *ret_min = min;
    *ret_max = max;
  } 

  /* threshold image */
  template <class T>
  image<uchar> *threshold(image<T> *src, int t) {
    int width = src->width();
    int height = src->height();
    image<uchar> *dst = new image<uchar>(width, height);
    
    for (int y = 0; y < height; y++) {
      for (int x = 0; x < width; x++) {
        imRef(dst, x, y) = (imRef(src, x, y) >= t);
      }
    }

    return dst;
  }

} // namespace