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hmm not half bad

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This commit is contained in:
Brooke Vibber 2023-03-21 18:04:51 -07:00
parent cecd031352
commit 3216af39d6
1 changed files with 39 additions and 6 deletions
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45
dither-image.js
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@ -540,10 +540,15 @@ function decimate(input, palette, n, inputError, y) {
// Median cut!
// https://en.wikipedia.org/wiki/Median_cut
//let buckets = [input.slice()];
let initial = dither(palette);
let buckets = [initial.output.map((i) => atariRGB[palette[i]])];
let buckets = [input.slice()];
//let initial = dither(palette);
//let buckets = [initial.output.map((i) => atariRGB[palette[i]])];
let medianCut = (bucket, range) => {
if (bucket.length < 2) {
console.log(bucket);
throw new Error('short bucket');
}
//console.log('medianCut', bucket, range);
// Sort by the channel with the greatest range,
// then cut the bucket in two at the median.
if (range.g >= range.r && range.g >= range.b) {
@ -554,6 +559,7 @@ function decimate(input, palette, n, inputError, y) {
bucket.sort((a, b) => b.b - a.b);
}
let half = bucket.length >> 1;
//console.log('cutting', half, bucket.length);
return [bucket.slice(0, half), bucket.slice(half)];
};
while (buckets.length < n) {
@ -579,9 +585,25 @@ function decimate(input, palette, n, inputError, y) {
//let rgb = bucket
// .reduce((acc, rgb) => acc.inc(rgb), new RGB(0, 0, 0))
// .divide(bucket.length);
// scale to the max luma
let lumas = bucket.map((rgb) => rgb.luma());
console.log(lumas);
let luma = Math.max(...lumas);
let rgb = bucket[lumas.indexOf(luma)];
console.log(rgb, luma);
let from = rgb.luma();
if (from > 0) {
rgb = rgb.multiply(luma / rgb.luma());
}
console.log(rgb, luma);
if (!rgb) {
throw new Error('xxx');
}
// Take the channel-brightest color in the bucket
//let rgb = bucket[bucket.length - 1];
// bad
//rgb = bucket[bucket.length - 1];
// Take the luma-brightest color in the bucket
//let rgb = bucket.slice().sort((a, b) => b.luma() - a.luma())[bucket.length - 1];
@ -591,11 +613,22 @@ function decimate(input, palette, n, inputError, y) {
// Combine the brightest of each channel
// this is kinda good
/*
let rgb = new RGB(
Math.max(...bucket.map((rgb) => rgb.r)),
Math.max(...bucket.map((rgb) => rgb.g)),
Math.max(...bucket.map((rgb) => rgb.b))
);
*/
// combine the median of each channel
// sux
/*
let rgb = new RGB(
bucket.map((rgb) => rgb.r).sort((a, b) => b - a)[bucket.length >> 1],
bucket.map((rgb) => rgb.g).sort((a, b) => b - a)[bucket.length >> 1],
bucket.map((rgb) => rgb.b).sort((a, b) => b - a)[bucket.length >> 1]
);
*/
// Take the luma-median color in the bucket
//let rgb = bucket.slice().sort((a, b) => b.luma() - a.luma())[bucket.length >> 1];
@ -605,14 +638,14 @@ function decimate(input, palette, n, inputError, y) {
// .sort((a, b) => Math.max(b.r, b.g, b.b) - Math.max(a.r, b.g, b.b))[bucket.length >> 1];
// And map into the Atari palette
let dists = palette.map(( i) => rgb.difference(atariRGB[i]).magnitude());
let dists = palette.map((i) => rgb.difference(atariRGB[i]).magnitude());
let closest = Math.min(...dists);
let index = dists.indexOf(closest);
return palette[index];
});
// hack
decimated.sort((a, b) => a - b);
console.log(decimated);
//console.log(decimated);
decimated[0] = 0;
// Palette fits