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@jake-sl
Created April 15, 2023 01:45
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<body>
<input type="file" id="image-input" accept="image/*">
<input type="range" id="hue-range" min="0" max="360" value="0">
<input type="color" id="bg-color" value="#ffffff">
<canvas id="image-canvas"></canvas>
<script src="main.js"></script>
</body>
const imageInput = document.getElementById('image-input');
const hueRange = document.getElementById('hue-range');
const bgColor = document.getElementById('bg-color');
const canvas = document.getElementById('image-canvas');
const ctx = canvas.getContext('2d');
let img = new Image();
imageInput.addEventListener('change', (e) => {
const reader = new FileReader();
reader.onload = (event) => {
img.src = event.target.result;
img.onload = () => {
canvas.width = img.width;
canvas.height = img.height;
updateImage();
};
};
reader.readAsDataURL(e.target.files[0]);
});
hueRange.addEventListener('input', updateImage);
bgColor.addEventListener('input', updateBackground);
function createHueRotationMatrix(angle) {
const cosA = Math.cos(angle);
const sinA = Math.sin(angle);
const lumR = 0.213;
const lumG = 0.715;
const lumB = 0.072;
return [
lumR + cosA * (1 - lumR) + sinA * (-lumR),
lumG + cosA * (-lumG) + sinA * (-lumG),
lumB + cosA * (-lumB) + sinA * (1 - lumB),
0,
0,
lumR + cosA * (-lumR) + sinA * (0.143),
lumG + cosA * (1 - lumG) + sinA * (0.14),
lumB + cosA * (-lumB) + sinA * (-0.283),
0,
0,
lumR + cosA * (-lumR) + sinA * (-(1 - lumR)),
lumG + cosA * (-lumG) + sinA * (lumG),
lumB + cosA * (1 - lumB) + sinA * (lumB),
0,
0,
0,
0,
0,
1,
0,
];
}
function updateImage() {
ctx.clearRect(0, 0, canvas.width, canvas.height);
// Draw the image in grayscale
ctx.filter = 'grayscale(100%)';
ctx.drawImage(img, 0, 0, canvas.width, canvas.height);
ctx.filter = 'none';
// Apply the hue rotation color matrix
const angle = (hueRange.value / 360) * 2 * Math.PI;
const matrix = createHueRotationMatrix(angle);
const matrixStr = `matrix(${matrix.join(', ')})`;
ctx.filter = matrixStr;
// Draw the colorized image onto the main canvas
ctx.drawImage(canvas, 0, 0, canvas.width, canvas.height);
ctx.filter = 'none';
}
function hslToRgb(h, s, l) {
let r, g, b;
if (s === 0) {
r = g = b = l; // achromatic
} else {
const hue2rgb = (p, q, t) => {
if (t < 0) t += 1;
if (t > 1) t -= 1;
if (t < 1 / 6) return p + (q - p) * 6 * t;
if (t < 1 / 2) return q;
if (t < 2 / 3) return p + (q - p) * (2 / 3 - t) * 6;
return p;
};
const q = l < 0.5 ? l * (1 + s) : l + s - l * s;
const p = 2 * l - q;
r = hue2rgb(p, q, h + 1 / 3);
g = hue2rgb(p, q, h);
b = hue2rgb(p, q, h - 1 / 3);
}
return [Math.round(r * 255), Math.round(g * 255), Math.round(b * 255)];
}
function rgbToHsl(r, g, b) {
r /= 255, g /= 255, b /= 255;
const max = Math.max(r, g, b), min = Math.min(r, g, b);
let h, s, l = (max + min) / 2;
if (max === min) {
h = s = 0; // achromatic
} else {
const d = max - min;
s = l > 0.5 ? d / (2 - max - min) : d / (max + min);
switch (max) {
case r: h = (g - b) / d + (g < b ? 6 : 0); break;
case g: h = (b - r) / d + 2; break;
case b: h = (r - g) / d + 4; break;
}
h /= 6;
}
return [h, s, l];
}
function updateBackground() {
canvas.style.backgroundColor = bgColor.value;
}
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