image-size/dist/esm/types/jp2.js

get dimensions of any image file

import { findBox, readUInt32BE, toUTF8String } from './utils.js';
export const JP2 = {
    validate(input) {
        const boxType = toUTF8String(input, 4, 8);
        if (boxType !== 'jP  ')
            return false;
        const ftypBox = findBox(input, 'ftyp', 0);
        if (!ftypBox)
            return false;
        const brand = toUTF8String(input, ftypBox.offset + 8, ftypBox.offset + 12);
        return brand === 'jp2 ';
    },
    calculate(input) {
        const jp2hBox = findBox(input, 'jp2h', 0);
        const ihdrBox = jp2hBox && findBox(input, 'ihdr', jp2hBox.offset + 8);
        if (ihdrBox) {
            return {
                height: readUInt32BE(input, ihdrBox.offset + 8),
                width: readUInt32BE(input, ihdrBox.offset + 12),
            };
        }
        throw new TypeError('Unsupported JPEG 2000 format');
    },
};