[gegl/soc-2011-ops] Added red-eye-removal op

[Robert Sasu <sasurobert src gnome org>]

commit 33d89a3ad03a19fa9cf892cc64b1e9f2d35b8413
Author: Robert Sasu <sasu robert gmail com>
Date:   Tue Aug 2 14:12:22 2011 +0300

    Added red-eye-removal op

 operations/workshop/red-eye-removal.c |  133 +++++++++++++++++++++++++++++++++
 1 files changed, 133 insertions(+), 0 deletions(-)
---
diff --git a/operations/workshop/red-eye-removal.c b/operations/workshop/red-eye-removal.c
new file mode 100644
index 0000000..51e0201
--- /dev/null
+++ b/operations/workshop/red-eye-removal.c
@@ -0,0 +1,133 @@
+/* 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/>.
+ *
+ * This plugin is used for removing the red-eye effect
+ * that occurs in flash photos.
+ *
+ * Based on a GIMP 1.2 Perl plugin by Geoff Kuenning
+ *
+ * Copyright (C) 2004  Robert Merkel <robert merkel benambra org>
+ * Copyright (C) 2006  Andreas RÃsdal <andrearo stud ntnu no>
+ * Copyright (C) 2011 Robert Sasu <sasu robert gmail com>
+ */
+
+#include "config.h"
+#include <glib/gi18n-lib.h>
+
+#ifdef GEGL_CHANT_PROPERTIES
+
+gegl_chant_double (threshold, _("Threshold"), 0.0, 0.8, 0.4,
+                   _("The value of the threshold"))
+
+#else
+
+#define GEGL_CHANT_TYPE_FILTER
+#define GEGL_CHANT_C_FILE       "red-eye-removal.c"
+
+#include "gegl-chant.h"
+#include <stdio.h>
+#include <math.h>
+
+#define RED_FACTOR    0.5133333
+#define GREEN_FACTOR  1
+#define BLUE_FACTOR   0.1933333
+
+#define SCALE_WIDTH   100
+
+static void prepare (GeglOperation *operation)
+{
+  gegl_operation_set_format (operation, "input", 
+                             babl_format ("RGBA float"));
+  gegl_operation_set_format (operation, "output",
+                             babl_format ("RGBA float"));
+}
+
+static void
+red_eye_reduction (gfloat *src,
+                   gint    offset,
+                   gfloat  threshold)
+{
+  const gint red   = 0;
+  const gint green = 1;
+  const gint blue  = 2;
+
+  gfloat dest;
+
+  gfloat adjusted_red       = src[offset + red] * RED_FACTOR;
+  gfloat adjusted_green     = src[offset + green] * GREEN_FACTOR;
+  gfloat adjusted_blue      = src[offset + blue] * BLUE_FACTOR;
+  gfloat adjusted_threshold = (threshold - 0.4) * 2;
+
+  if (adjusted_red >= adjusted_green - adjusted_threshold &&
+      adjusted_red >= adjusted_blue - adjusted_threshold)
+     {
+        dest = CLAMP (((gdouble) (adjusted_green + adjusted_blue)
+                      / (2.0  * RED_FACTOR)), 0.0, 1.0);
+     }
+  else
+     {
+        dest = src[offset + red];
+     }
+
+  src[offset] = dest;
+}
+
+
+
+static gboolean
+process (GeglOperation       *operation,
+         GeglBuffer          *input,
+         GeglBuffer          *output,
+         const GeglRectangle *result)
+{
+  GeglChantO              *o            = GEGL_CHANT_PROPERTIES (operation);
+  Babl                    *format       = babl_format ("RGBA float");
+
+  gfloat *src_buf;
+  gint    x;
+
+  src_buf = g_new0 (gfloat, result->width * result->height * 4);
+
+  gegl_buffer_get (input, 1.0, result, format, src_buf, GEGL_AUTO_ROWSTRIDE);
+
+  for (x = 0; x < result->width * result->height; x++)
+      red_eye_reduction (src_buf, 4 * x, (float) o->threshold);
+
+  gegl_buffer_set (output, result, format, src_buf, GEGL_AUTO_ROWSTRIDE);
+
+  g_free (src_buf);
+
+  return  TRUE;
+}
+
+
+static void
+gegl_chant_class_init (GeglChantClass *klass)
+{
+  GeglOperationClass       *operation_class;
+  GeglOperationFilterClass *filter_class;
+
+  operation_class = GEGL_OPERATION_CLASS (klass);
+  filter_class    = GEGL_OPERATION_FILTER_CLASS (klass);
+
+  filter_class->process    = process;
+  operation_class->prepare = prepare;
+
+  operation_class->categories  = "enhance";
+  operation_class->name        = "gegl:red-eye-removal";
+  operation_class->description = _("Performs red-eye-removal on the image.");
+}
+
+#endif