diff --git a/image.cpp b/image.cpp
index 8cb2994c..bfc454a0 100644
--- a/image.cpp
+++ b/image.cpp
@@ -5,16 +5,16 @@
  * terms of the GNU General Public License as published by the Free Software
  * Foundation, either version 3 of the License, or (at your option) any later
  * version.
- * 
+ *
  * libgim 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 libgim.  If not, see <http://www.gnu.org/licenses/>.
  *
- * Copyright 2011-2014 Danny Robson <danny@nerdcruft.net>
+ * Copyright 2011-2015 Danny Robson <danny@nerdcruft.net>
  */
 
 
@@ -26,6 +26,121 @@
 #include <fstream>
 
 
+//-----------------------------------------------------------------------------
+template <typename T>
+util::image::buffer<T>::buffer (size_t _w, size_t _h, size_t _s):
+    w (_w),
+    h (_h),
+    s (_s),
+    data (std::make_unique<T[]> (_w * _s))
+{
+    CHECK_NEQ (w * h, 0);
+    CHECK_GE (s, w);
+}
+
+
+//-----------------------------------------------------------------------------
+template <typename T>
+util::image::buffer<T>::buffer (size_t _w, size_t _h):
+    buffer<T> (_w, _h, _w)
+{ ; }
+
+
+//-----------------------------------------------------------------------------
+template <typename T>
+util::image::buffer<T>::buffer (size_t _w,
+                                size_t _h,
+                                size_t _s,
+                                std::unique_ptr<T[]> &&_data):
+    w (_w),
+    h (_h),
+    s (_s),
+    data (std::move (_data))
+{
+    CHECK_NEQ (w * h, 0);
+    CHECK_GE (s, w);
+}
+
+
+//-----------------------------------------------------------------------------
+template <typename T>
+template <typename U>
+util::image::buffer<U>
+util::image::buffer<T>::alloc (void) const
+{
+    return buffer<U> (w, h, s);
+}
+
+
+//-----------------------------------------------------------------------------
+template <typename T>
+void
+util::image::buffer<T>::fill (const T v)
+{
+    std::fill (data.get (), data.get () + w * s, v);
+}
+
+
+//-----------------------------------------------------------------------------
+template <typename T, typename U>
+static U
+rescale (T v)
+{
+    return v * sizeof (U) / sizeof (T);
+}
+
+
+//-----------------------------------------------------------------------------
+template <typename T>
+template <typename U>
+util::image::buffer<U>
+util::image::buffer<T>::clone (void) const
+{
+    auto out = alloc<U> ();
+
+    std::transform (data.get (),
+                    data.get () + w * s,
+                    out.data.get (),
+                    [] (auto v) {
+        return rescale<T,U> (v);
+    });
+
+    return out;
+}
+
+
+//-----------------------------------------------------------------------------
+template <typename T>
+util::image::buffer<T>
+util::image::buffer<T>::downsample (unsigned factor)
+{
+    CHECK_GT (factor, 1);
+
+    size_t w_ = w / factor;
+    size_t h_ = h / factor;
+    size_t s_ = w_;
+
+    CHECK_NEQ (w_, 0);
+    CHECK_NEQ (h_, 0);
+
+    buffer out { w_, h_, s_, std::make_unique<T[]> (w_ * h_) };
+
+    // Do a really shitty nearest neighbour average in src-space.
+    for (size_t y = 0; y < out.h; ++y)
+        for (size_t x = 0; x < out.w; ++x) {
+            size_t src00 = ((y * factor) + 0) * s + (x * factor) + 0;
+            size_t src01 = ((y * factor) + 0) * s + (x * factor) + 1;
+            size_t src10 = ((y * factor) + 1) * s + (x * factor) + 0;
+            size_t src11 = ((y * factor) + 1) * s + (x * factor) + 1;
+
+            size_t dst_offset = y * out.s + x;
+            out.data[dst_offset] = (src00 + src01 + src10 + src11) / 4;
+        }
+
+    return out;
+}
+
+
 //-----------------------------------------------------------------------------
 static void
 write_netpbm (const uint8_t *restrict pixels,
@@ -82,3 +197,8 @@ util::ppm::write (const uint8_t *restrict pixels,
     static const char MAGIC[] = "P6";
     write_netpbm (pixels, width, height, stride, path, MAGIC);
 }
+
+
+//-----------------------------------------------------------------------------
+template struct util::image::buffer<uint8_t>;
+template util::image::buffer<uint8_t> util::image::buffer<uint8_t>::alloc (void) const;
diff --git a/image.hpp b/image.hpp
index 4c62086e..fc4b38b0 100644
--- a/image.hpp
+++ b/image.hpp
@@ -5,16 +5,16 @@
  * terms of the GNU General Public License as published by the Free Software
  * Foundation, either version 3 of the License, or (at your option) any later
  * version.
- * 
+ *
  * libgim 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 libgim.  If not, see <http://www.gnu.org/licenses/>.
  *
- * Copyright 2011-2014 Danny Robson <danny@nerdcruft.net>
+ * Copyright 2011-2015 Danny Robson <danny@nerdcruft.net>
  */
 
 #ifndef __UTIL_IMAGE_HPP
@@ -22,9 +22,40 @@
 
 #include <cstdint>
 #include <cstdlib>
+#include <memory>
 #include <boost/filesystem/path.hpp>
 
+
 namespace util {
+    namespace image {
+        template <typename T>
+        struct buffer {
+            buffer (size_t w, size_t h);
+            buffer (size_t w, size_t h, size_t s);
+            buffer (size_t w, size_t h, size_t s, std::unique_ptr<T[]> &&data);
+
+            buffer (const buffer<T>&) = delete;
+            buffer (buffer<T> &&) = default;
+
+            void fill (T);
+
+            template <typename U>
+            buffer<U> alloc (void) const;
+
+            template <typename U>
+            buffer<U> clone (void) const;
+
+            buffer<T> downsample (unsigned factor);
+
+            size_t w;
+            size_t h;
+            size_t s;
+
+            std::unique_ptr<T[]> data;
+        };
+    }
+
+
     struct pgm {
         static void write (const uint8_t *restrict pixels,
                            size_t width,