[gegl] workshop: add edges and details op

[Øyvind "pippin" Kolås <ok src gnome org>]

commit a1b14f12ebf736b47920208e77a0d1d7aac26409
Author: Øyvind Kolås <pippin gimp org>
Date:   Sat May 9 12:04:29 2020 +0200

    workshop: add edges and details op
    
    A new meta-op that permits does a dual band-pass enhancement for
    noise reduction and edge boosting.

 operations/workshop/edges-and-details.c | 190 ++++++++++++++++++++++++++++++++
 operations/workshop/meson.build         |   1 +
 2 files changed, 191 insertions(+)
---
diff --git a/operations/workshop/edges-and-details.c b/operations/workshop/edges-and-details.c
new file mode 100644
index 000000000..285ce72a0
--- /dev/null
+++ b/operations/workshop/edges-and-details.c
@@ -0,0 +1,190 @@
+/* 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 <https://www.gnu.org/licenses/>.
+ *
+ * Copyright 2020 Øyvind Kolås <pippin gimp org>
+ */
+
+#include "config.h"
+#include <glib/gi18n-lib.h>
+#include <math.h>
+
+#ifdef GEGL_PROPERTIES
+
+property_double (radius1, _("Detail band"), 1.1)
+    description(_("Features size for detail band, used for noise removal."))
+    value_range (0.0, 100.0)
+    ui_range    (0.5, 2.0)
+    ui_meta     ("unit", "pixel-distance")
+
+property_double (scale1, _("Detail scale, negative values dimnishes signal in detail band, postivie values 
increases signal."), -1.6)
+    description(_("Scaling factor for image features at radius, -1 cancels them out 1.0 edge enhances"))
+    value_range (-3.0, 100.0)
+    ui_range    (-3.0, 3.0)
+
+property_double (radius2, _("Feature band"), 4.0)
+    description(_("Expressed as standard deviation, in pixels"))
+    value_range (0.0, 100.0)
+    ui_range    (0.5, 20.0)
+    ui_meta     ("unit", "pixel-distance")
+
+property_double (scale2, _("Feature scale"), 0.0)
+    description(_("Scaling factor for image features at radius, -1 cancels them out 1.0 edge enhances, when 
set to 0.0 performance of op is higher."))
+    value_range (-3.0, 100.0)
+    ui_range    (-3.0, 3.0)
+
+#else
+
+#define GEGL_OP_META
+#define GEGL_OP_NAME     edges_and_details
+#define GEGL_OP_C_SOURCE edges-and-details.c
+
+#include "gegl-op.h"
+
+typedef struct
+{
+  GeglNode *input;
+  GeglNode *add1;
+  GeglNode *dog1;
+  GeglNode *mul1;
+  GeglNode *add2;
+  GeglNode *dog2;
+  GeglNode *mul2;
+  GeglNode *output;
+} State;
+
+static float compute_radius2 (float center_radius, float bw)
+{
+  return center_radius / (bw + 1);
+}
+static float compute_radius1 (float center_radius, float bw)
+{
+  return compute_radius2(center_radius, bw) * bw;
+}
+
+static void
+update_graph (GeglOperation *operation)
+{
+  GeglProperties *o = GEGL_PROPERTIES (operation);
+  State *state = o->user_data;
+  if (!state) return;
+  float bw = 0.625;
+  GeglNode *iter = state->input;
+
+  if (fabs(o->scale1) > 0.01)
+  {
+    float radius1 = compute_radius1(o->radius1, bw);
+    float radius2 = compute_radius2(o->radius1, bw);
+    gegl_node_set (state->dog1, "radius1", radius1,
+                                "radius2", radius2,
+                                NULL);
+    gegl_node_set (state->mul1, "value", o->scale1, NULL);
+    gegl_node_connect_from (state->add1, "input",
+                            iter, "output");
+    gegl_node_connect_from (state->dog1, "input",
+                            iter, "output");
+    gegl_node_connect_from (state->mul1, "input",
+                            state->dog1, "output");
+    gegl_node_connect_from (state->add1, "aux",
+                            state->mul1, "output");
+    iter = state->add1;
+  }
+  if (fabs (o->scale2) > 0.01)
+  {
+    float radius1 = compute_radius1(o->radius2, bw);
+    float radius2 = compute_radius2(o->radius2, bw);
+    gegl_node_set (state->dog2, "radius1", radius1,
+                                "radius2", radius2,
+                                NULL);
+    gegl_node_set (state->mul2, "value", o->scale2, NULL);
+    gegl_node_connect_from (state->add2, "input",
+                            iter, "output");
+    gegl_node_connect_from (state->dog2, "input",
+                            iter, "output");
+    gegl_node_connect_from (state->mul2, "input",
+                            state->dog2, "output");
+    gegl_node_connect_from (state->add2, "aux",
+                            state->mul2, "output");
+    iter = state->add2;
+  }
+  gegl_node_connect_from (state->output, "input",
+                          iter,  "output");
+}
+
+static void
+attach (GeglOperation *operation)
+{
+  GeglProperties *o = GEGL_PROPERTIES (operation);
+  GeglNode *gegl = operation->node;
+  State *state = g_malloc0 (sizeof (State));
+  o->user_data = state;
+
+  state->input    = gegl_node_get_input_proxy (gegl, "input");
+  state->output   = gegl_node_get_output_proxy (gegl, "output");
+  state->add1     = gegl_node_new_child (gegl, "operation", "gegl:add", NULL);
+  state->mul1     = gegl_node_new_child (gegl, "operation", "gegl:multiply", "value", 0.0, NULL);
+  state->dog1     = gegl_node_new_child (gegl, "operation", "gegl:difference-of-gaussians", NULL);
+
+  state->add2     = gegl_node_new_child (gegl, "operation", "gegl:add", NULL);
+  state->mul2     = gegl_node_new_child (gegl, "operation", "gegl:multiply", "value", 0.0, NULL);
+  state->dog2     = gegl_node_new_child (gegl, "operation", "gegl:difference-of-gaussians", NULL);
+
+  update_graph (operation);
+}
+
+static void
+my_set_property (GObject      *object,
+                 guint         property_id,
+                 const GValue *value,
+                 GParamSpec   *pspec)
+{
+  GeglProperties  *o     = GEGL_PROPERTIES (object);
+
+  set_property (object, property_id, value, pspec);
+
+  if (o)
+    update_graph ((void*)object);
+}
+
+static void
+dispose (GObject *object)
+{
+   GeglProperties  *o     = GEGL_PROPERTIES (object);
+   g_clear_pointer (&o->user_data, g_free);
+   G_OBJECT_CLASS (gegl_op_parent_class)->dispose (object);
+}
+
+static void
+gegl_op_class_init (GeglOpClass *klass)
+{
+  GObjectClass       *object_class;
+  GeglOperationClass *operation_class;
+
+  object_class    = G_OBJECT_CLASS (klass);
+  object_class->dispose      = dispose;
+  object_class->set_property = my_set_property;
+
+  operation_class = GEGL_OPERATION_CLASS (klass);
+
+  operation_class->attach = attach;
+
+  gegl_operation_class_set_keys (operation_class,
+    "name",        "gegl:edges-and-details",
+    "title",       _("Edges and Details"),
+    "categories",  "enhance:sharpen:denoise",
+    "description", _("Two band parametric equalizer, for noise reduction and edge enhancement."),
+    NULL);
+}
+
+#endif
diff --git a/operations/workshop/meson.build b/operations/workshop/meson.build
index 8d8bbab05..3f1147c9d 100644
--- a/operations/workshop/meson.build
+++ b/operations/workshop/meson.build
@@ -11,6 +11,7 @@ libraries = [
   { 'name': 'demosaic-bimedian', },
   { 'name': 'demosaic-simple', },
   { 'name': 'ditto', },
+  { 'name': 'edges-and-details', },
   { 'name': 'gcr', },
   { 'name': 'gradient-map', },
   { 'name': 'hstack', },