[gegl/soc-2012-ops] Cartoon Operation

[Maxime Nicco <maxnicco src gnome org>]

commit cd995f1d36d18a46546ed78efec99cd1234e73bb
Author: Angh <maxime nicco gmail fr>
Date:   Wed Jul 11 20:14:21 2012 +0200

    Cartoon Operation
    
    Implementation based on code from photocopy by Han Lo
    
    Run but very slow

 operations/common/cartoon.c |  377 +++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 377 insertions(+), 0 deletions(-)
---
diff --git a/operations/common/cartoon.c b/operations/common/cartoon.c
new file mode 100644
index 0000000..e948824
--- /dev/null
+++ b/operations/common/cartoon.c
@@ -0,0 +1,377 @@
+/* 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 1997 Spencer Kimball
+ * Copyright 2012 Maxime Nicco <maxime nicco gmail com>
+ */
+
+#include "config.h"
+#include <glib/gi18n-lib.h>
+
+#ifdef GEGL_CHANT_PROPERTIES
+
+gegl_chant_double (mask_radius, _("Mask radius"),   0.0, 50.0, 7.0, _("Mask radius"))
+
+gegl_chant_double (pct_black, _("Percent black"),   0.0, 1.0, 0.2, _("Percent black"))
+
+#else
+
+#define GEGL_CHANT_TYPE_AREA_FILTER
+#define GEGL_CHANT_C_FILE       "cartoon.c"
+
+#include "gegl-chant.h"
+#include <stdio.h>
+#include <math.h>
+#include <stdlib.h>
+
+#define THRESHOLD 1.0
+
+typedef struct {
+  gdouble      prev_mask_radius;
+  gdouble      prev_pct_black;
+  gdouble      prev_ramp;
+} Ramps;
+
+static void
+grey_blur_buffer(GeglBuffer *input,
+		 gdouble mask_radius,
+		 GeglBuffer **dest1,
+		 GeglBuffer **dest2)
+{
+  GeglNode *gegl, *image, *write1, *write2, *grey, *blur1, *blur2;
+  gdouble radius, std_dev1, std_dev2;
+
+  gegl = gegl_node_new();
+  image = gegl_node_new_child(gegl,
+			      "operation", "gegl:buffer-source",
+			      "buffer", input,
+			      NULL);
+  grey = gegl_node_new_child(gegl,
+			     "operation", "gegl:grey",
+			     NULL);
+
+  radius   = 1.0;
+  radius   = fabs (radius) + 1.0;
+  std_dev1 = sqrt (-(radius * radius) / (2 * log (1.0 / 255.0)));
+  
+  radius   = fabs (mask_radius) + 1.0;
+  std_dev2 = sqrt (-(radius * radius) / (2 * log (1.0 / 255.0)));
+
+  blur1 =  gegl_node_new_child(gegl,
+			       "operation", "gegl:gaussian-blur",
+			       "std_dev_x", std_dev1,
+			       "std_dev_y", std_dev1,
+			       NULL);
+  blur2 =  gegl_node_new_child(gegl,
+			       "operation", "gegl:gaussian-blur",
+			       "std_dev_x", std_dev2,
+			       "std_dev_y", std_dev2,
+			       NULL);
+
+  write1 = gegl_node_new_child(gegl,
+			       "operation", "gegl:buffer-sink",
+			       "buffer", dest1, NULL);
+  
+  write2 = gegl_node_new_child(gegl,
+			       "operation", "gegl:buffer-sink",
+			       "buffer", dest2, NULL);
+  
+  gegl_node_link_many (image, grey, blur1, write1, NULL);
+  gegl_node_process (write1);
+  
+  gegl_node_link_many (grey, blur2, write2, NULL);
+  gegl_node_process (write2);
+
+  g_object_unref (gegl);
+}
+
+static gdouble
+compute_ramp (GeglBuffer *input,
+	      GeglOperation *operation,
+	      gdouble pct_black)
+{
+  GeglChantO *o                    = GEGL_CHANT_PROPERTIES (operation);
+
+  GeglRectangle *whole_region;
+  gint    n_pixels;
+  gint    hist[100];
+  gdouble diff;
+  gint    count;
+  gfloat pixel1, pixel2;
+  gint x;
+  gint y;
+  gint i;
+  gint sum;
+  GeglSampler *sampler1;
+  GeglSampler *sampler2;
+  GeglBuffer *dest1, *dest2;
+  
+  whole_region = gegl_operation_source_get_bounding_box (operation, "input");
+  grey_blur_buffer(input, o->mask_radius, &dest1, &dest2);
+      
+  sampler1 = gegl_buffer_sampler_new (dest1,
+				      babl_format ("Y' float"),
+				      GEGL_SAMPLER_LINEAR);
+  
+  sampler2 = gegl_buffer_sampler_new (dest2,
+				      babl_format ("Y' float"),
+				      GEGL_SAMPLER_LINEAR);
+  
+  n_pixels = whole_region->width * whole_region->height;
+  memset (hist, 0, sizeof (int) * 100);
+  count = 0;
+  x = whole_region->x;
+  y = whole_region->y;
+
+  while (n_pixels--)
+    {
+      gegl_sampler_get (sampler1,
+			            x,
+                        y,
+                        NULL,
+                        &pixel1);
+
+      gegl_sampler_get (sampler2,
+                        x,
+                        y,
+                        NULL,
+                        &pixel2);
+
+    if (pixel2 != 0)
+    {
+      diff = (gdouble) pixel1 / (gdouble) pixel2;
+
+      if (diff < 1.0)
+      {
+        hist[(int) (diff * 100)] += 1;
+        count += 1;
+      }
+    }
+	 
+      x++;
+      if (x>=whole_region->x + whole_region->width)
+        {
+          x=whole_region->x;
+          y++;
+        }
+    }
+  
+  g_object_unref (sampler1);
+  g_object_unref (sampler2);
+  g_object_unref (dest1);
+  g_object_unref (dest2);
+
+  if (pct_black == 0.0 || count == 0)
+    return 1.0;
+
+  sum = 0;
+  for (i = 0; i < 100; i++)
+  {
+    sum += hist[i];
+    if (((gdouble) sum / (gdouble) count) > pct_black)
+      return (1.0 - (gdouble) i / 100.0);
+  }
+
+  return 0.0;
+
+}
+
+static void prepare (GeglOperation *operation)
+{
+  GeglChantO              *o;
+    
+  o       = GEGL_CHANT_PROPERTIES (operation);
+  
+  gegl_operation_set_format (operation, "input",
+                             babl_format ("Y'CbCrA float"));
+  gegl_operation_set_format (operation, "output",
+                             babl_format ("Y'CbCrA float"));
+
+ if(o->chant_data)
+    {
+      Ramps* ramps = (Ramps*) o->chant_data;
+
+      /* hack so that thresholds are only calculated once */
+      if(ramps->prev_mask_radius != o->mask_radius ||
+	 ramps->prev_pct_black       != o->pct_black)
+	{
+	  g_slice_free (Ramps, o->chant_data);
+	  o->chant_data = NULL;
+	}
+    }
+}
+
+static gboolean
+process (GeglOperation       *operation,
+         GeglBuffer          *input,
+         GeglBuffer          *output,
+         const GeglRectangle *result,
+         gint                 level)
+{
+  GeglChantO *o                    = GEGL_CHANT_PROPERTIES (operation);
+
+  GeglBuffer *dest1;
+  GeglBuffer *dest2;
+  GeglSampler *sampler1;
+  GeglSampler *sampler2;
+
+  Ramps* ramps;
+
+  gint n_pixels;
+  gfloat pixel1, pixel2;
+  gfloat *out_pixel;
+  gint x;
+  gint y;
+  
+
+  gdouble diff;
+  Ramps *get_ramps;
+  gdouble ramp;
+  gdouble mult = 0.0;
+  
+  gfloat *dst_buf;
+  GeglRectangle *whole_region;
+  
+  static GStaticMutex mutex = G_STATIC_MUTEX_INIT;
+
+  dst_buf = g_slice_alloc (result->width * result->height * 4 * sizeof(gfloat));
+
+  gegl_buffer_get (input, result, 1.0, babl_format ("Y'CbCrA float"), dst_buf, GEGL_AUTO_ROWSTRIDE, GEGL_ABYSS_NONE);
+
+
+  g_static_mutex_lock (&mutex);
+  if(o->chant_data == NULL) 
+    {
+      whole_region = gegl_operation_source_get_bounding_box (operation, "input");
+      gegl_buffer_set_extent(input, whole_region); 
+      o->chant_data = g_slice_new (Ramps);
+      ramps = (Ramps*) o->chant_data;
+      ramps->prev_ramp = compute_ramp(input,operation,o->pct_black);
+      ramps->prev_mask_radius = o->mask_radius;
+      ramps->prev_pct_black   = o->pct_black;
+    }
+  g_static_mutex_unlock (&mutex);
+
+  gegl_buffer_set_extent(input, result);
+  grey_blur_buffer(input, o->mask_radius, &dest1, &dest2);
+  
+  sampler1 = gegl_buffer_sampler_new (dest1,
+				      babl_format ("Y' float"),
+				      GEGL_SAMPLER_LINEAR);
+  
+  sampler2 = gegl_buffer_sampler_new (dest2,
+				      babl_format ("Y' float"),
+				      GEGL_SAMPLER_LINEAR);
+  
+  x = result->x;
+  y = result->y;
+  n_pixels = result->width * result->height;
+  
+  out_pixel = dst_buf;
+  get_ramps = (Ramps*) o->chant_data;
+  ramp = get_ramps->prev_ramp;
+
+  while (n_pixels--)
+    {
+      gegl_sampler_get (sampler1,
+			            x,
+                        y,
+                        NULL,
+                        &pixel1);
+
+      gegl_sampler_get (sampler2,
+                        x,
+                        y,
+                        NULL,
+                        &pixel2);
+
+      if (pixel2 != 0)
+      {
+        diff = (gdouble) pixel1 / (gdouble) pixel2;
+        if (diff < THRESHOLD)
+        {
+          if (GEGL_FLOAT_EQUAL(ramp,0.0))
+            mult = 0.0;
+          else
+            mult = (ramp - MIN (ramp, (THRESHOLD - diff))) / ramp;
+        }
+        else
+          mult = 1.0;
+      }   
+              
+      *out_pixel = CLAMP(pixel1 * mult, 0.0, 1.0);
+
+      out_pixel += 4;
+      
+      x++;
+      if (x>=result->x + result->width)
+        {
+          x=result->x;
+          y++;
+        }
+    }
+
+  
+  gegl_buffer_set (output, result, 0, babl_format ("Y'CbCrA float"), dst_buf, GEGL_AUTO_ROWSTRIDE);
+  g_slice_free1 (result->width * result->height * 4 * sizeof(gfloat), dst_buf);
+ 
+  g_object_unref (sampler1);
+  g_object_unref (sampler2);
+  g_object_unref (dest1);
+  g_object_unref (dest2);
+ 
+  whole_region = gegl_operation_source_get_bounding_box (operation, "input");
+  gegl_buffer_set_extent(input, whole_region);
+  return  TRUE;
+}
+
+static void
+finalize (GObject *object)
+{
+  GeglChantO *o = GEGL_CHANT_PROPERTIES (object);
+
+  if (o->chant_data)
+    {
+      g_slice_free (Ramps, o->chant_data);
+      o->chant_data = NULL;
+    }
+
+  G_OBJECT_CLASS (gegl_chant_parent_class)->finalize (object);
+}
+
+static void
+gegl_chant_class_init (GeglChantClass *klass)
+{
+  GObjectClass               *object_class;
+  GeglOperationClass       *operation_class;
+  GeglOperationFilterClass *filter_class;
+
+  
+  object_class    = G_OBJECT_CLASS (klass);
+  operation_class = GEGL_OPERATION_CLASS (klass);
+  filter_class    = GEGL_OPERATION_FILTER_CLASS (klass);
+
+  object_class->finalize = finalize;
+  operation_class->prepare = prepare;
+  filter_class->process    = process;
+
+  gegl_operation_class_set_keys (operation_class,
+				 "categories" , "artistic",
+				 "name"       , "gegl:cartoon",
+				 "description", _("Cartoon effect"),
+				 NULL);
+}
+
+#endif