[gegl] color-to-alpha: Remove unused macros

[Mukund Sivaraman <muks src gnome org>]

commit c44d22afcf2a1b6f63c1cd52fe5615834d133d1e
Author: Mukund Sivaraman <muks banu com>
Date:   Wed Aug 31 19:05:52 2011 +0530

    color-to-alpha: Remove unused macros

 operations/workshop/color-to-alpha.c |    3 ---
 1 files changed, 0 insertions(+), 3 deletions(-)
---
diff --git a/operations/workshop/color-to-alpha.c b/operations/workshop/color-to-alpha.c
index 269c256..d316afb 100644
--- a/operations/workshop/color-to-alpha.c
+++ b/operations/workshop/color-to-alpha.c
@@ -36,9 +36,6 @@ gegl_chant_color (value, _("Color"), "black",
 #include <stdio.h>
 #include <math.h>
 
-#define PRV_WIDTH      40
-#define PRV_HEIGHT     20
-
 static void prepare (GeglOperation *operation)
 {
   gegl_operation_set_format (operation, "input",