ops/workshop: add ink simulator

Initial sketch of a spectral proofing filter.

2 files changed, 371 insertions, 0 deletions

diff --git a/operations/workshop/Makefile.am b/operations/workshop/Makefile.am
index 8457d6e1..c259a313 100644
--- a/operations/workshop/Makefile.am
+++ b/operations/workshop/Makefile.am
@@ -23,6 +23,7 @@ op_LTLIBRARIES =    \
 	gaussian-blur-iir.la \
 	gblur-1d.la \
 	hstack.la \
+	ink-simulator.la \
 	kuwahara.la \
 	mandelbrot.la \
 	rawbayer-load.la \
diff --git a/operations/workshop/ink-simulator.c b/operations/workshop/ink-simulator.c
new file mode 100644
index 00000000..a31c2841
--- /dev/null
+++ b/operations/workshop/ink-simulator.c
@@ -0,0 +1,370 @@
+/* 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 2014 Øyvind Kolås <pippin@gimp.org>
+ */
+
+#include "config.h"
+#include <glib/gi18n-lib.h>
+
+#ifdef GEGL_CHANT_PROPERTIES
+
+#define DEFAULT_INKS \
+"illuminant = 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1\n" \
+"substrate  = white\n" \
+"ink1 = cyan\n"\
+"ink2 = yellow\n"\
+"ink3 = magenta\n"\
+"ink4 = black opaque\n"
+
+gegl_chant_multiline (config, _("ink configuration"), DEFAULT_INKS,
+         _("Textual desciption of inks passed in"))
+
+#else
+
+#define GEGL_CHANT_TYPE_POINT_FILTER
+#define GEGL_CHANT_C_FILE       "ink-simulator.c"
+
+#include "gegl-chant.h"
+
+#define SPECTRUM_BANDS 20
+
+typedef struct _Spectrum Spectrum;
+struct _Spectrum {
+  float bands[SPECTRUM_BANDS];
+  /* 20 bands, spaced as follows :
+   *
+   * 0 = 390 - 405nm
+   * 1 = 410 - 425nm
+   * ....
+   */
+};
+
+/* from http://cvrl.ucl.ac.uk/cones.htm */
+static Spectrum STANDARD_OBSERVER_L   = {{
+0.002177, 0.0158711, 0.03687185, 0.06265, 0.13059, 0.26828, 0.57836, 0.849104, 0.9704655, 0.9793335, 0.85568175, 0.59266275, 0.30191075, 0.11285, 0.032197, 0.007657, 0.0017424, 0.0004039, 0.000009, 0.000002
+}};
+static Spectrum STANDARD_OBSERVER_M   = {{
+0.00207, 0.01863, 0.057983, 0.11151, 0.221277, 0.4010105, 0.75920, 0.97423, 0.93118, 0.694917, 0.37578, 0.14093, 0.03995, 0.0096, 0.002, 0.0004, 0.0001095,
+  0.0000026, 0
+}};
+static Spectrum STANDARD_OBSERVER_S   = {{
+  0.05312, 0.45811575, 0.9226575, 0.83515125, 0.46085625, 0.146032125, 0.03805695, 0.00723844, 0.0010894, 0.000158823, 0.0000025, 0.000000336, 0
+}};
+
+/* Better reflectances for this sure would be nice */
+#define REFLECTANCE_CYAN    {{1,1,1,1,1,1,1,1,0,0,0,0,0,0,0,0,0,0,0,0}}
+#define REFLECTANCE_MAGENTA {{1,1,1,0,0,0,0,0,0,1,1,1,0,0,0,0,0,0,0,0}}
+#define REFLECTANCE_YELLOW  {{0,0,0,0,0,1,1,1,1,1,1,1,1,0,0,0,0,0,0,0}}
+#define REFLECTANCE_RED     {{0,0,0,0,0,0,0,0,0,0,1,1,1,1,1,1,1,0,0,0}}
+#define REFLECTANCE_GREEN   {{0,0,0,0,0,1,1,1,1,0,0,0,0,0,0,0,0,0,0,0}}
+#define REFLECTANCE_BLUE    {{0,1,1,1,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0}}
+#define REFLECTANCE_BLACK   {{0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0}}
+#define REFLECTANCE_GRAY    {{0.5,0.5,0.5,0.5,0.5,0.5,0.5,0.5,0.5,0.5,0.5,0.5,0.5,0.5,0.5,0.5,0.5,0.5,0.5,0.5}}
+#define REFLECTANCE_WHITE   {{0,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1}}
+#define ILLUMINANT_E         REFLECTANCE_WHITE
+
+/* the even illuminant; which is easy and almost cheating */
+static Spectrum ILLUMINANT            = ILLUMINANT_E;
+static Spectrum SUBSTRATE_REFLECTANCE = REFLECTANCE_WHITE;
+
+static int inks = 3;
+static Spectrum INK_REFLECTANCE_INK1 = REFLECTANCE_GREEN;
+static Spectrum INK_REFLECTANCE_INK2 = REFLECTANCE_BLACK;
+static Spectrum INK_REFLECTANCE_INK3 = REFLECTANCE_YELLOW;
+static Spectrum INK_REFLECTANCE_INK4 = REFLECTANCE_WHITE;
+static Spectrum INK_REFLECTANCE_INK5 = REFLECTANCE_WHITE;
+static int ink1_opaque = 0;
+static int ink2_opaque = 0;
+static int ink3_opaque = 0;
+static int ink4_opaque = 0;
+static int ink5_opaque = 0;
+
+
+static Spectrum spectrum_remove_light (Spectrum s, Spectrum ink, float factor)
+{
+  int i;
+  for (i = 0; i < SPECTRUM_BANDS; i++)
+  {
+    s.bands[i] = s.bands[i] * (1.0 - factor) +
+                 s.bands[i] * ink.bands[i] * factor;
+  }
+  return s;
+}
+
+static Spectrum spectrum_add_color (Spectrum s, Spectrum ink, float factor)
+{
+  int i;
+  for (i = 0; i < SPECTRUM_BANDS; i++)
+  {
+    s.bands[i] = s.bands[i] * (1.0 - factor) + ink.bands[i] * factor;
+  }
+  return s;
+}
+
+static float spectrum_observed_l (Spectrum s)
+{
+  float result = 0.0;
+  int i;
+  for (i = 0; i < SPECTRUM_BANDS; i++)
+    result += s.bands[i] * STANDARD_OBSERVER_L.bands[i];
+  return (result / SPECTRUM_BANDS) * 3;
+}
+
+static float spectrum_observed_m (Spectrum s)
+{
+  float result = 0.0;
+  int i;
+  for (i = 0; i < SPECTRUM_BANDS; i++)
+    result += s.bands[i] * STANDARD_OBSERVER_M.bands[i];
+  return (result / SPECTRUM_BANDS) * 3;
+}
+
+static float spectrum_observed_s (Spectrum s)
+{
+  float result = 0.0;
+  int i;
+  for (i = 0; i < SPECTRUM_BANDS; i++)
+    result += s.bands[i] * STANDARD_OBSERVER_S.bands[i];
+  return (result / SPECTRUM_BANDS) * 3;
+}
+
+static void parse_config (GeglOperation *operation);
+
+static void
+prepare (GeglOperation *operation)
+{
+
+  /* this RGBA float is interpreted as CMYK ! */
+  gegl_operation_set_format (operation, "input", babl_format ("RGBA float"));
+
+  gegl_operation_set_format (operation, "output", babl_format ("RGB float"));
+
+
+  parse_config (operation);
+}
+
+static gboolean
+process (GeglOperation       *op,
+         void                *in_buf,
+         void                *out_buf,
+         glong                samples,
+         const GeglRectangle *roi,
+         gint                 level)
+{
+  gfloat *in  = in_buf;
+  gfloat *out = out_buf;
+
+  while (samples--)
+    {
+      Spectrum spec = ILLUMINANT;
+      float l, m, s;
+
+      spec = spectrum_remove_light (spec, SUBSTRATE_REFLECTANCE, 1.0);
+      if (inks >=1)
+      {
+        if (ink1_opaque)
+          spec = spectrum_add_color (spec, INK_REFLECTANCE_INK1, in[0]);
+        else
+          spec = spectrum_remove_light (spec, INK_REFLECTANCE_INK1, in[0]);
+      }
+      if (inks >=2)
+      {
+        if (ink2_opaque)
+          spec = spectrum_add_color (spec, INK_REFLECTANCE_INK2, in[1]);
+        else
+          spec = spectrum_remove_light (spec, INK_REFLECTANCE_INK2, in[1]);
+      }
+      if (inks >=3)
+      {
+        if (ink3_opaque)
+          spec = spectrum_add_color (spec, INK_REFLECTANCE_INK3, in[2]);
+        else
+          spec = spectrum_remove_light (spec, INK_REFLECTANCE_INK3, in[2]);
+      }
+      if (inks >=4)
+      {
+        if (ink4_opaque)
+          spec = spectrum_add_color (spec, INK_REFLECTANCE_INK4, in[3]);
+        else
+          spec = spectrum_remove_light (spec, INK_REFLECTANCE_INK4, in[3]);
+      }
+
+      l = spectrum_observed_l (spec) /6;
+      m = spectrum_observed_m (spec) /6;
+      s = spectrum_observed_s (spec) /6;
+
+      /* this LMS to linear RGB -- likely no right..  */
+      
+      out[0] = ((30.83) * l + (-29.83) * m + (1.61) * s);
+      out[1] = ((-6.481) * l + (17.7155) * m + (-2.532) * s);
+      out[2] = ((-0.375) * l + (-1.19906) * m + (14.27) * s);
+
+
+      in  += 4;
+      out += 3;
+    }
+  return TRUE;
+}
+
+
+static Spectrum parse_spectrum (gchar *spectrum)
+{
+  Spectrum s = REFLECTANCE_WHITE;
+  if (!spectrum)
+    return s;
+  while (*spectrum == ' ') spectrum ++;
+
+  if (g_str_has_prefix (spectrum, "red"))
+  { Spectrum color = REFLECTANCE_RED; s = color;
+  } else if (g_str_has_prefix (spectrum, "green"))
+  { Spectrum color = REFLECTANCE_GREEN; s = color;
+  } else if (g_str_has_prefix (spectrum, "blue"))
+  { Spectrum color = REFLECTANCE_BLUE; s = color;
+  } else if (g_str_has_prefix (spectrum, "cyan"))
+  { Spectrum color = REFLECTANCE_CYAN; s = color;
+  } else if (g_str_has_prefix (spectrum, "yellow"))
+  { Spectrum color = REFLECTANCE_YELLOW; s = color;
+  } else if (g_str_has_prefix (spectrum, "magenta"))
+  { Spectrum color = REFLECTANCE_MAGENTA; s = color;
+  } else if (g_str_has_prefix (spectrum, "white"))
+  { Spectrum color = REFLECTANCE_WHITE; s = color;
+  } else if (g_str_has_prefix (spectrum, "black"))
+  { Spectrum color = REFLECTANCE_BLACK; s = color;
+  } else if (g_str_has_prefix (spectrum, "gray"))
+  { Spectrum color = REFLECTANCE_GRAY; s = color;
+  } else
+  {
+    int band = 0;
+    band = 0;
+    do {
+    s.bands[band++] = g_strtod (spectrum, &spectrum);
+    } while (spectrum && band < SPECTRUM_BANDS);
+  }
+
+  return s;
+}
+
+static void parse_config_line (GeglOperation *operation,
+                               const char *line)
+{
+  Spectrum s;
+  if (!line)
+    return;
+
+  if (!strchr (line, '='))
+    return;
+
+  while (*line == ' ') line++;
+  
+  s = parse_spectrum (strchr (line, '=') + 1);
+
+  inks = 0;
+
+  if (g_str_has_prefix (line, "illuminant"))
+    ILLUMINANT = s;
+  else if (g_str_has_prefix (line, "substrate"))
+    SUBSTRATE_REFLECTANCE = s;
+  else if (g_str_has_prefix (line, "ink1"))
+    {
+      INK_REFLECTANCE_INK1 = s;
+      if (strstr(line, "opaque"))
+        ink1_opaque = 1;
+      inks = MAX(inks, 1);
+    }
+  else if (g_str_has_prefix (line, "ink2"))
+    {
+      INK_REFLECTANCE_INK2 = s;
+      inks = MAX(inks, 2);
+      if (strstr(line, "opaque"))
+        ink2_opaque = 2;
+    }
+  else if (g_str_has_prefix (line, "ink3"))
+    {
+      INK_REFLECTANCE_INK3 = s;
+      inks = MAX(inks, 3);
+      if (strstr(line, "opaque"))
+        ink3_opaque = 3;
+    }
+  else if (g_str_has_prefix (line, "ink4"))
+    {
+      INK_REFLECTANCE_INK4 = s;
+      inks = MAX(inks, 4);
+      if (strstr(line, "opaque"))
+        ink4_opaque = 4;
+    }
+}
+
+static void parse_config (GeglOperation *operation)
+{
+  GeglChantO *o = GEGL_CHANT_PROPERTIES (operation);
+  const char *p = o->config;
+  GString *str;
+  
+  if (!p)
+    return;
+
+  memset (&INK_REFLECTANCE_INK1, 0, sizeof (INK_REFLECTANCE_INK1));
+  memset (&INK_REFLECTANCE_INK2, 0, sizeof (INK_REFLECTANCE_INK2));
+  memset (&INK_REFLECTANCE_INK3, 0, sizeof (INK_REFLECTANCE_INK3));
+  memset (&INK_REFLECTANCE_INK4, 0, sizeof (INK_REFLECTANCE_INK4));
+  memset (&INK_REFLECTANCE_INK5, 0, sizeof (INK_REFLECTANCE_INK5));
+  ink1_opaque = 0;
+  ink2_opaque = 0;
+  ink3_opaque = 0;
+  ink4_opaque = 0;
+  ink5_opaque = 0;
+
+  str = g_string_new ("");
+  while (*p)
+  {
+    switch (*p)
+    {
+      case '\n':
+        parse_config_line (operation, str->str);
+        g_string_assign (str, "");
+        break;
+      default:
+        g_string_append_c (str, *p);
+        break;
+    }
+    p++;
+  }
+
+  g_string_free (str, TRUE);
+}
+
+static void
+gegl_chant_class_init (GeglChantClass *klass)
+{
+  GeglOperationClass            *operation_class;
+  GeglOperationPointFilterClass *point_filter_class;
+
+  operation_class = GEGL_OPERATION_CLASS (klass);
+  point_filter_class = GEGL_OPERATION_POINT_FILTER_CLASS (klass);
+
+  point_filter_class->process = process;
+  operation_class->prepare = prepare;
+
+  gegl_operation_class_set_keys (operation_class,
+  "name"        , "gegl:ink-simulator",
+  "categories"  , "misc",
+  "description" ,
+        _("spectral ink simulator, for softproofing/simulating press inks"
+          ""),
+        NULL);
+}
+
+#endif