From 0ea766a5a6abbb9e83a6a4b50b316039a673348e Mon Sep 17 00:00:00 2001
From: Brooke Vibber <bvibber@pobox.com>
Date: Tue, 27 Aug 2024 19:09:28 -0700
Subject: [PATCH] use the raw luma

---
 dither-image.js | 20 ++++++--------------
 1 file changed, 6 insertions(+), 14 deletions(-)

diff --git a/dither-image.js b/dither-image.js
index 8db870a..ababc3c 100644
--- a/dither-image.js
+++ b/dither-image.js
@@ -247,21 +247,13 @@ function colorize(input) {
         // Try dithering with this palette.
         for (let x = 0; x < width; x++) {
             let rgb = inputPixel(x, error);
+            let luma = Math.round(rgb.luma() / 15);
+            let pick = luma;
 
-            // find the closest possible color
-            // @todo consider doing the difference scoring in luminance and hue spaces
-            shortest = Infinity;
-            let pick = 1;
-
-            for (let i = 0; i < palette.length; i++) {
-                let diff = rgb.difference(atariRGB[palette[i]]);
-                let dist = diff.magnitude();
-                if (dist < shortest) {
-                    nextError = diff;
-                    shortest = dist;
-                    pick = i;
-                }
-            }
+            let diff = rgb.difference(atariRGB[palette[pick]]);
+            let dist = diff.magnitude();
+            nextError = diff;
+            shortest = dist;
 
             output[x] = pick;
             distance += shortest;