Add image.h

felz/src/image.h

@@ -0,0 +1,101 @@
+/*
+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
+*/
+
+/* a simple image class */
+
+#ifndef IMAGE_H
+#define IMAGE_H
+
+#include <cstring>
+
+template <class T>
+class image {
+ public:
+  /* create an image */
+  image(const int width, const int height, const bool init = true);
+
+  /* delete an image */
+  ~image();
+
+  /* init an image */
+  void init(const T &val);
+
+  /* copy an image */
+  image<T> *copy() const;
+
+  /* get the width of an image. */
+  int width() const { return w; }
+
+  /* get the height of an image. */
+  int height() const { return h; }
+
+  /* image data. */
+  T *data;
+
+  /* row pointers. */
+  T **access;
+
+ private:
+  int w, h;
+};
+
+/* use imRef to access image data. */
+#define imRef(im, x, y) (im->access[y][x])
+
+/* use imPtr to get pointer to image data. */
+#define imPtr(im, x, y) &(im->access[y][x])
+
+template <class T>
+image<T>::image(const int width, const int height, const bool init) {
+  w = width;
+  h = height;
+  data = new T[w * h];  // allocate space for image data
+  access = new T*[h];   // allocate space for row pointers
+
+  // initialize row pointers
+  for (int i = 0; i < h; i++)
+    access[i] = data + (i * w);  
+
+  if (init)
+    memset(data, 0, w * h * sizeof(T));
+}
+
+template <class T>
+image<T>::~image() {
+  delete [] data; 
+  delete [] access;
+}
+
+template <class T>
+void image<T>::init(const T &val) {
+  T *ptr = imPtr(this, 0, 0);
+  T *end = imPtr(this, w-1, h-1);
+  while (ptr <= end)
+    *ptr++ = val;
+}
+
+
+template <class T>
+image<T> *image<T>::copy() const {
+  image<T> *im = new image<T>(w, h, false);
+  memcpy(im->data, data, w * h * sizeof(T));
+  return im;
+}
+
+#endif
+