@blocklet/images/lib/blurhash.js

support functions for blocklet image validation

"use strict";
var __importDefault = (this && this.__importDefault) || function (mod) {
    return (mod && mod.__esModule) ? mod : { "default": mod };
};
Object.defineProperty(exports, "__esModule", { value: true });
exports.getBlurhash = getBlurhash;
const fs_1 = __importDefault(require("fs"));
const jimp_1 = require("jimp");
const utils_1 = require("@jimp/utils");
const blurhash_1 = require("blurhash");
const image_type_1 = __importDefault(require("image-type"));
const is_svg_1 = __importDefault(require("is-svg"));
async function getBlurhash(filePath) {
    if (!fs_1.default.existsSync(filePath)) {
        throw new Error(`File not found: ${filePath}`);
    }
    const buffer = fs_1.default.readFileSync(filePath);
    const type = (0, image_type_1.default)(buffer);
    if (!type) {
        // svg 转位图
        if ((0, is_svg_1.default)(buffer)) {
            // return empty blurhash
            return '';
        }
        throw new Error(`File is not a valid image: ${filePath}`);
    }
    // Read image using Jimp
    const image = await jimp_1.Jimp.read(buffer);
    const { width, height } = image.bitmap;
    // Convert image data to RGBA array
    const pixels = new Uint8ClampedArray(width * height * 4);
    // Scan through each pixel and add to array
    image.scan(0, 0, width, height, (x, y) => {
        const pixelIndex = (y * width + x) * 4;
        const rgba = (0, utils_1.intToRGBA)(image.getPixelColor(x, y));
        pixels[pixelIndex] = rgba.r;
        pixels[pixelIndex + 1] = rgba.g;
        pixels[pixelIndex + 2] = rgba.b;
        pixels[pixelIndex + 3] = rgba.a;
    });
    const blurhash = (0, blurhash_1.encode)(pixels, width, height, 4, 4);
    return blurhash;
}