# HG changeset patch
# User Carnë Draug <carandraug+dev@gmail.com>
# Date 1353003467 0
# Node ID 37a21f615d6729929aac67a205590f7091b3d935
# Parent  dffb28f47ea8c1f7b1de2064c0f0e52e88124c85
rgb2ind: great speedup increase creating indexed image (changeset 89c8d8f made a proper indexed image that used less memory but was much slower to create)

diff -r dffb28f47ea8 -r 37a21f615d67 scripts/image/rgb2ind.m
--- a/scripts/image/rgb2ind.m	Mon Nov 12 05:32:02 2012 +0000
+++ b/scripts/image/rgb2ind.m	Thu Nov 15 18:17:47 2012 +0000
@@ -51,12 +51,9 @@
     error ("rgb2ind: arguments must all have the same size");
   endif
 
-  map = unique([R(:) G(:) B(:)], "rows");
-  ## RGB values for each point of the image are listed and expanded to compare
-  ## with the colormap values. We then find the indexes when all 3 match and
-  ## rebuild the image to its original size
-  [x, ~] = find (squeeze (all (bsxfun (@eq, reshape(map', [1 3 rows(map)]), [R(:) G(:) B(:)]), 2))');
-  x = reshape (x, size (R));
+  map    = unique([R(:) G(:) B(:)], "rows");
+  [~, x] = ismember ([R(:) G(:) B(:)], map, "rows");
+  x      = reshape (x, size (R));
 
   ## a colormap is of class double and values between 0 and 1
   switch class (R)