speice.io/blog/2024-11-15-playing-with-fire/3-log-density/paintLogarithmic.ts

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export function paintLogarithmic(width: number, height: number, histogram: number[]): ImageData {
const image = new ImageData(width, height);
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const histogramLog = new Array<number>();
histogram.forEach(value => histogramLog.push(Math.log(value)));
let histogramLogMax = -Infinity;
for (let value of histogramLog) {
histogramLogMax = Math.max(histogramLogMax, value);
}
for (let i = 0; i < histogram.length; i++) {
const pixelIndex = i * 4;
image.data[pixelIndex] = 0; // red
image.data[pixelIndex + 1] = 0; // green
image.data[pixelIndex + 2] = 0; // blue
image.data[pixelIndex + 3] = histogramLog[i] / histogramLogMax * 0xff;
}
return image;
}