[gegl] color-reduction: do quantization in gamma space

[Ãyvind KolÃs <ok src gnome org>]

commit a1216c5519f5dff613ed8f584014802773bb41b3
Author: Ãyvind KolÃs <pippin gimp org>
Date:   Sat Sep 22 16:40:09 2012 +0100

    color-reduction: do quantization in gamma space
    
    The destination of color-reduction almost always is files with an sRGB color
    space - doing the quantization and dithering in linear space causes excessive
    banding in the dark regions.

 operations/common/color-reduction.c |   22 +++++++++++-----------
 1 files changed, 11 insertions(+), 11 deletions(-)
---
diff --git a/operations/common/color-reduction.c b/operations/common/color-reduction.c
index 0fab02b..96de858 100644
--- a/operations/common/color-reduction.c
+++ b/operations/common/color-reduction.c
@@ -48,8 +48,8 @@ gegl_chant_enum (dither_strategy, _("Dithering Strategy"), GeglDitherStrategy,
 static void
 prepare (GeglOperation *operation)
 {
-  gegl_operation_set_format (operation, "input", babl_format ("RGBA u16"));
-  gegl_operation_set_format (operation, "output", babl_format ("RGBA u16"));
+  gegl_operation_set_format (operation, "input", babl_format ("R'G'B'A u16"));
+  gegl_operation_set_format (operation, "output", babl_format ("R'G'B'A u16"));
 }
 
 static void
@@ -122,7 +122,7 @@ process_floyd_steinberg (GeglBuffer *input,
 
     /* Pull input row */
 
-    gegl_buffer_get (input, &line_rect, 1.0, babl_format ("RGBA u16"), line_buf,
+    gegl_buffer_get (input, &line_rect, 1.0, babl_format ("R'G'B'A u16"), line_buf,
                      GEGL_AUTO_ROWSTRIDE, GEGL_ABYSS_NONE);
 
     /* Process the row */
@@ -175,7 +175,7 @@ process_floyd_steinberg (GeglBuffer *input,
 
     /* Push output row */
 
-    gegl_buffer_set (output, &line_rect, 0, babl_format ("RGBA u16"), line_buf, GEGL_AUTO_ROWSTRIDE);
+    gegl_buffer_set (output, &line_rect, 0, babl_format ("R'G'B'A u16"), line_buf, GEGL_AUTO_ROWSTRIDE);
     line_rect.y++;
   }
 
@@ -220,7 +220,7 @@ process_bayer (GeglBuffer *input,
   {
     guint x;
 
-    gegl_buffer_get (input, &line_rect, 1.0, babl_format ("RGBA u16"), line_buf,
+    gegl_buffer_get (input, &line_rect, 1.0, babl_format ("R'G'B'A u16"), line_buf,
                      GEGL_AUTO_ROWSTRIDE, GEGL_ABYSS_NONE);
 
     for (x = 0; x < result->width; x++)
@@ -242,7 +242,7 @@ process_bayer (GeglBuffer *input,
       }
     }
 
-    gegl_buffer_set (output, &line_rect, 0, babl_format ("RGBA u16"), line_buf, GEGL_AUTO_ROWSTRIDE);
+    gegl_buffer_set (output, &line_rect, 0, babl_format ("R'G'B'A u16"), line_buf, GEGL_AUTO_ROWSTRIDE);
     line_rect.y++;
   }
 
@@ -273,7 +273,7 @@ process_random_covariant (GeglBuffer *input,
   {
     guint x;
 
-    gegl_buffer_get (input, &line_rect, 1.0, babl_format ("RGBA u16"), line_buf,
+    gegl_buffer_get (input, &line_rect, 1.0, babl_format ("R'G'B'A u16"), line_buf,
                      GEGL_AUTO_ROWSTRIDE, GEGL_ABYSS_NONE);
 
     for (x = 0; x < result->width; x++)
@@ -296,7 +296,7 @@ process_random_covariant (GeglBuffer *input,
       }
     }
 
-    gegl_buffer_set (output, &line_rect, 0, babl_format ("RGBA u16"), line_buf, GEGL_AUTO_ROWSTRIDE);
+    gegl_buffer_set (output, &line_rect, 0, babl_format ("R'G'B'A u16"), line_buf, GEGL_AUTO_ROWSTRIDE);
     line_rect.y++;
   }
 
@@ -349,7 +349,7 @@ process_random (GeglBuffer *input,
       }
     }
 
-    gegl_buffer_set (output, &line_rect, 0, babl_format ("RGBA u16"), line_buf, GEGL_AUTO_ROWSTRIDE);
+    gegl_buffer_set (output, &line_rect, 0, babl_format ("R'G'B'A u16"), line_buf, GEGL_AUTO_ROWSTRIDE);
     line_rect.y++;
   }
 
@@ -380,7 +380,7 @@ process_no_dither (GeglBuffer *input,
   {
     guint x;
 
-    gegl_buffer_get (input, &line_rect, 1.0, babl_format ("RGBA u16"), line_buf,
+    gegl_buffer_get (input, &line_rect, 1.0, babl_format ("R'G'B'A u16"), line_buf,
                      GEGL_AUTO_ROWSTRIDE, GEGL_ABYSS_NONE);
 
     for (x = 0; x < result->width; x++)
@@ -394,7 +394,7 @@ process_no_dither (GeglBuffer *input,
       }
     }
 
-    gegl_buffer_set (output, &line_rect, 0, babl_format ("RGBA u16"), line_buf, GEGL_AUTO_ROWSTRIDE);
+    gegl_buffer_set (output, &line_rect, 0, babl_format ("R'G'B'A u16"), line_buf, GEGL_AUTO_ROWSTRIDE);
     line_rect.y++;
   }