diff --git a/chromakey/alpha.png b/chromakey/alpha.png
index 96b4049..7408e26 100644
Binary files a/chromakey/alpha.png and b/chromakey/alpha.png differ
diff --git a/chromakey/bluescreen.m b/chromakey/bluescreen.m
index 30c27d7..f50c82d 100644
--- a/chromakey/bluescreen.m
+++ b/chromakey/bluescreen.m
@@ -23,9 +23,9 @@
 ## Author: Jens <jens@orion>
 ## Created: 2020-10-03
 
-function retval = bluescreen (img_name, k_ds, k_gain)
+function retval = bluescreen (img_name, k_sb, k_ds, k_cw)
 im = im2double(imread(img_name));
-im_rgb = imresize(im, 2);
+im_rgb = imresize(im, 1);
 se = strel('square',3)
 
 ref_rgb = toRef([0 0.5 1], size(im_rgb));
@@ -35,20 +35,28 @@ close all;
 figure;
 imshow(ref_rgb);
 
+figure;
+despilled_rgb_matte = im_rgb - k_sb*ref_rgb;
+imshow(despilled_rgb_matte);
+
 figure;
 despilled_rgb = im_rgb - k_ds*ref_rgb;
 imshow(despilled_rgb);
 
 figure;
-mask = min(1, k_gain*similarity(rgb2hsv(despilled_rgb), rgb2hsv(ref_rgb)));
-imshow(mask);
+matte = min(1, k_cw*similarity(despilled_rgb_matte, ref_rgb));
+imshow(matte);
 
 figure;
-final = despilled_rgb.*mask;
+final = despilled_rgb.*matte;
 imshow(final);
 
-imwrite(final, 'final.png','png','alpha', mask);
-imwrite(mask, 'alpha.png','png');
+figure;
+edges = coloredges(despilled_rgb_matte, ref_rgb);
+imshow(edges);
+
+imwrite(final, 'final.png','png','alpha', matte);
+imwrite(matte, 'alpha.png','png');
 
 retval = 0;
 
@@ -57,7 +65,15 @@ function r = toRef(ref, d)
 endfunction
 
 function s = similarity(im, ref)
-	s = abs(im(:,:,1) - ref(:,:,1));
+	im = rgb2hsv(im);
+	ref = rgb2hsv(ref);
+	s = (im(:,:,1) - ref(:,:,1)).^2;
+endfunction
+
+function s = coloredges(im, ref)
+	im = rgb2hsv(im);
+	ref = rgb2hsv(ref);
+	s = max(0, im(:,:,1) - ref(:,:,1));
 endfunction
 
 endfunction
diff --git a/chromakey/final.png b/chromakey/final.png
index 412bdc1..8b1cc89 100644
Binary files a/chromakey/final.png and b/chromakey/final.png differ