gegl r1840 - in trunk: . operations/workshop

[ok svn gnome org]

Author: ok
Date: Sun Jan 13 23:01:30 2008
New Revision: 1840
URL: http://svn.gnome.org/viewvc/gegl?rev=1840&view=rev

Log:
* operations/workshop/demosaic-bimedian.c: Added a bimedian
demosaicing filter contributed by Bradley Broom <bmbroom gmail com>.


Added:
   trunk/operations/workshop/demosaic-bimedian.c
Modified:
   trunk/ChangeLog

Added: trunk/operations/workshop/demosaic-bimedian.c
==============================================================================
--- (empty file)
+++ trunk/operations/workshop/demosaic-bimedian.c	Sun Jan 13 23:01:30 2008
@@ -0,0 +1,199 @@
+/* This file is an image processing operation for GEGL
+ *
+ * GEGL is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 3 of the License, or (at your option) any later version.
+ *
+ * GEGL 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with GEGL; if not, see <http://www.gnu.org/licenses/>.
+ *
+ * Copyright 2006 Ãyvind KolÃs <pippin gimp org>
+ * Copyright 2008 Bradley Broom <bmbroom gmail com>
+ */
+#if GEGL_CHANT_PROPERTIES
+
+gegl_chant_int (pattern, 0, 3, 0, "Bayer pattern used, 0 seems to work for some nikon files, 2 for some Fuji files.")
+ 
+#else
+
+#define GEGL_CHANT_NAME            demosaic_bimedian
+#define GEGL_CHANT_SELF            "demosaic-bimedian.c"
+#define GEGL_CHANT_DESCRIPTION     "Performs a grayscale2color demosaicing of an image, using bimedian interpolation."
+#define GEGL_CHANT_CATEGORIES      "blur"
+
+#define GEGL_CHANT_AREA_FILTER
+
+#include "gegl-chant.h"
+
+static void
+demosaic (GeglChantOperation *op,
+          GeglBuffer *src,
+          GeglBuffer *dst);
+
+static gboolean
+process (GeglOperation       *operation,
+         GeglBuffer          *input,
+         GeglBuffer          *output,
+         const GeglRectangle *result)
+{
+  GeglChantOperation  *self = GEGL_CHANT_OPERATION (operation);
+
+  demosaic (self, input, output);
+
+  return  TRUE;
+}
+
+/* Returns the median of four floats. We define the median as the average of
+ * the central two elements.
+ */
+static inline gfloat
+m4 (gfloat a, gfloat b, gfloat c, gfloat d)
+{
+  gfloat t;
+
+  /* Sort ab */
+  if (a > b)
+    {
+      t = b;
+      b = a;
+      a = t;
+    }
+  /* Sort abc */
+  if (b > c)
+    {
+      t = c;
+      c = b;
+      if (a > t)
+        {
+          b = a;
+          a = t;
+        }
+      else
+        b = t;
+    }
+  /* Return average of central two elements. */
+  if (d >= c) /* Sorted order would be abcd */
+    return (b + c) / 2.0;
+  else if (d >= a) /* Sorted order would be either abdc or adbc */
+    return (b + d) / 2.0;
+  else /* Sorted order would be dabc */
+    return (a + b) / 2.0;
+}
+
+/* Defines to make the row/col offsets below obvious. */
+#define ROW src_extent->width
+#define COL 1
+
+/* We expect src_extent to have a one pixel border around all four sides
+ * of dst_extent.
+ */
+static void
+demosaic (GeglChantOperation *op,
+          GeglBuffer *src,
+          GeglBuffer *dst)
+{
+  const GeglRectangle *src_extent = gegl_buffer_get_extent (src);
+  const GeglRectangle *dst_extent = gegl_buffer_get_extent (dst);
+  gint x,y;
+  gint offset, doffset;
+  gfloat *src_buf;
+  gfloat *dst_buf;
+
+  src_buf = g_malloc0 (gegl_buffer_get_pixel_count (src) * 4);
+  dst_buf = g_malloc0 (gegl_buffer_get_pixel_count (dst) * 4 * 3);
+  
+  gegl_buffer_get (src, 1.0, NULL, babl_format ("Y float"), src_buf,
+                   GEGL_AUTO_ROWSTRIDE);
+
+  offset = ROW + COL;
+  doffset = 0;
+  for (y=dst_extent->y; y<dst_extent->height + dst_extent->y; y++)
+    {
+      for (x=dst_extent->x; x<dst_extent->width + dst_extent->x; x++)
+        {
+          gfloat red=0.0;
+          gfloat green=0.0;
+          gfloat blue=0.0;
+
+          if ((y + op->pattern%2)%2==0)
+            {
+              if ((x+op->pattern/2)%2==1)
+                {
+                  /* GRG
+                   * BGB
+                   * GRG
+                   */
+                  blue =(src_buf[offset-COL]+src_buf[offset+COL])/2.0;
+                  green=src_buf[offset];
+                  red  =(src_buf[offset-ROW]+src_buf[offset+ROW])/2.0;
+                }
+              else
+                {
+                  /* RGR
+                   * GBG
+                   * RGR
+                   */
+                  blue =src_buf[offset];
+                  green=m4(src_buf[offset-ROW], src_buf[offset-COL],
+                           src_buf[offset+COL], src_buf[offset+ROW]);
+                  red  =m4(src_buf[offset-ROW-COL], src_buf[offset-ROW+COL],
+                           src_buf[offset+ROW-COL], src_buf[offset+ROW+COL]);
+                }
+            }
+          else
+            {
+              if ((x+op->pattern/2)%2==1)
+                {
+                  /* BGB
+                   * GRG
+                   * BGB
+                   */
+                  blue =m4(src_buf[offset-ROW-COL], src_buf[offset-ROW+COL],
+                           src_buf[offset+ROW-COL], src_buf[offset+ROW+COL]);
+                  green=m4(src_buf[offset-ROW], src_buf[offset-COL],
+                           src_buf[offset+COL], src_buf[offset+ROW]);
+                  red  =src_buf[offset];
+                }
+              else
+                {
+                  /* GBG
+                   * RGR
+                   * GBG
+                   */
+                  blue =(src_buf[offset-ROW]+src_buf[offset+ROW])/2.0;
+                  green=src_buf[offset];
+                  red  =(src_buf[offset-COL]+src_buf[offset+COL])/2.0;
+                }
+            }
+          
+          dst_buf [doffset*3+0] = red;
+          dst_buf [doffset*3+1] = green;
+          dst_buf [doffset*3+2] = blue;
+
+          offset++;
+          doffset++;
+        }
+      offset+=2;
+    }
+
+  gegl_buffer_set (dst, NULL, babl_format ("RGB float"), dst_buf, GEGL_AUTO_ROWSTRIDE);
+  g_free (src_buf);
+  g_free (dst_buf);
+}
+
+/* Specify required extra pixels around dst_extent: one pixel on every side.
+ */
+static void tickle (GeglOperation *operation)
+{
+  GeglOperationAreaFilter *area = GEGL_OPERATION_AREA_FILTER (operation);
+  area->right = area->bottom = 1;
+  area->left = area->top = 1;
+}
+
+#endif