From b74036ef8d732ba2712c7c547762f02a98de7c26 Mon Sep 17 00:00:00 2001
From: Brion Vibber <brion@pobox.com>
Date: Sat, 18 Mar 2023 22:08:22 -0700
Subject: [PATCH] hmm

---
 dither-image.js | 32 +++++++++++++++-----------------
 1 file changed, 15 insertions(+), 17 deletions(-)

diff --git a/dither-image.js b/dither-image.js
index 1b8f8ee..6999624 100644
--- a/dither-image.js
+++ b/dither-image.js
@@ -508,9 +508,10 @@ function decimate(input, palette, n, inputError) {
 
     // not happy with this alt yet
 
-    let colorCount = new Int32Array(256);
-    let hues = new Int32Array(16);
-    let lumaByHue = new Int32Array(16);
+    let colorCount = [];
+    for (let i = 0; i < 256; i++) {
+        colorCount[i] = 0;
+    }
 
     const bestColor = (rgb) => {
         let best = -1;
@@ -528,26 +529,23 @@ function decimate(input, palette, n, inputError) {
         let rgb = inputPixel(x);
         let i = bestColor(rgb);
         colorCount[i]++;
-        let hue = i >> 4;
-        hues[hue]++;
-        let luma = i & 0xf;
-        lumaByHue[hue] = Math.max(luma, lumaByHue[hue]);
     }
 
-    let xhues = [];
-    xhues.push.apply(xhues, hues);
-
-    let popularHues = xhues.map((count, hue) => {return {count, hue}}).sort((a, b) => b.count - a.count);
-    decimated = [0];
-    for (let {count, hue} of popularHues) {
-        let luma = lumaByHue[hue];
-        if (luma > 0 && count > 0) {
-            decimated.push((hue << 4) | luma);
-        }
+    for (let keep of reserved) {
+        colorCount[keep] = Infinity;
+    }
+    let popular = colorCount
+        .map((count, color) => {return {count, color}})
+        .filter(({count}) => count > 0)
+        .sort((a, b) => b.count - a.count)
+    decimated = [];
+    for (let {color} of popular) {
+        decimated.push(color);
         if (decimated.length == n) {
             break;
         }
     }
+    decimated.sort((a, b) => a - b);
 
     /*