woltappblurhash
JavaScript encoder and decoder for the Wolt BlurHash algorithm
Install
npm install --save blurhashSee react-blurhash to use blurhash with React.
API
decode(blurhash: string, width: number, height: number, punch?: number) => Uint8ClampedArray
Decodes a blurhash string to pixels
Example
import { decode } from "blurhash";
const pixels = decode("LEHV6nWB2yk8pyo0adR*.7kCMdnj", 32, 32);
const canvas = document.createElement("canvas");
const ctx = canvas.getContext("2d");
const imageData = ctx.createImageData(width, height);
imageData.data.set(pixels);
ctx.putImageData(imageData, 0, 0);
document.body.append(canvas);encode(pixels: Uint8ClampedArray, width: number, height: number, componentX: number, componentY: number) => string
Encodes pixels to a blurhash string
import { encode } from "blurhash";
const loadImage = async src =>
new Promise((resolve, reject) => {
const img = new Image();
img.onload = () => resolve(img);
img.onerror = (...args) => reject(args);
img.src = src;
});
const getImageData = image => {
const canvas = document.createElement("canvas");
canvas.width = image.width;
canvas.height = image.height;
const context = canvas.getContext("2d");
context.drawImage(image, 0, 0);
return context.getImageData(0, 0, image.width, image.height);
};
const encodeImageToBlurhash = async imageUrl => {
const image = await loadImage(imageUrl);
const imageData = getImageData(image);
return encode(imageData.data, imageData.width, imageData.height, 4, 4);
};isBlurhashValid(blurhash: string) => { result: boolean; errorReason?: string }
import { isBlurhashValid } from "blurhash";
const validRes = isBlurhashValid("LEHV6nWB2yk8pyo0adR*.7kCMdnj");
// { result: true }
const invalidRes = isBlurhashValid("???");
// { result: false, errorReason: "The blurhash string must be at least 6 characters" }