image-size/dist/types/tiff.mjs

get dimensions of any image file

// lib/types/utils.ts
var decoder = new TextDecoder();
var toUTF8String = (input, start = 0, end = input.length) => decoder.decode(input.slice(start, end));
var toHexString = (input, start = 0, end = input.length) => input.slice(start, end).reduce((memo, i) => memo + `0${i.toString(16)}`.slice(-2), "");
var getView = (input, offset) => new DataView(input.buffer, input.byteOffset + offset);
var readUInt16BE = (input, offset = 0) => getView(input, offset).getUint16(0, false);
var readUInt16LE = (input, offset = 0) => getView(input, offset).getUint16(0, true);
var readUInt32BE = (input, offset = 0) => getView(input, offset).getUint32(0, false);
var readUInt32LE = (input, offset = 0) => getView(input, offset).getUint32(0, true);
var readUInt64 = (input, offset, isBigEndian) => getView(input, offset).getBigUint64(0, !isBigEndian);
var methods = {
  readUInt16BE,
  readUInt16LE,
  readUInt32BE,
  readUInt32LE
};
function readUInt(input, bits, offset = 0, isBigEndian = false) {
  const endian = isBigEndian ? "BE" : "LE";
  const methodName = `readUInt${bits}${endian}`;
  return methods[methodName](input, offset);
}

// lib/types/tiff.ts
var CONSTANTS = {
  TAG: {
    WIDTH: 256,
    HEIGHT: 257,
    COMPRESSION: 259
  },
  TYPE: {
    SHORT: 3,
    LONG: 4,
    LONG8: 16
  },
  ENTRY_SIZE: {
    STANDARD: 12,
    BIG: 20
  },
  COUNT_SIZE: {
    STANDARD: 2,
    BIG: 8
  }
};
function readIFD(input, { isBigEndian, isBigTiff }) {
  const ifdOffset = isBigTiff ? Number(readUInt64(input, 8, isBigEndian)) : readUInt(input, 32, 4, isBigEndian);
  const entryCountSize = isBigTiff ? CONSTANTS.COUNT_SIZE.BIG : CONSTANTS.COUNT_SIZE.STANDARD;
  return input.slice(ifdOffset + entryCountSize);
}
function readTagValue(input, type, offset, isBigEndian) {
  switch (type) {
    case CONSTANTS.TYPE.SHORT:
      return readUInt(input, 16, offset, isBigEndian);
    case CONSTANTS.TYPE.LONG:
      return readUInt(input, 32, offset, isBigEndian);
    case CONSTANTS.TYPE.LONG8: {
      const value = Number(readUInt64(input, offset, isBigEndian));
      if (value > Number.MAX_SAFE_INTEGER) {
        throw new TypeError("Value too large");
      }
      return value;
    }
    default:
      return 0;
  }
}
function nextTag(input, isBigTiff) {
  const entrySize = isBigTiff ? CONSTANTS.ENTRY_SIZE.BIG : CONSTANTS.ENTRY_SIZE.STANDARD;
  if (input.length > entrySize) {
    return input.slice(entrySize);
  }
}
function extractTags(input, { isBigEndian, isBigTiff }) {
  const tags = {};
  let temp = input;
  while (temp?.length) {
    const code = readUInt(temp, 16, 0, isBigEndian);
    const type = readUInt(temp, 16, 2, isBigEndian);
    const length = isBigTiff ? Number(readUInt64(temp, 4, isBigEndian)) : readUInt(temp, 32, 4, isBigEndian);
    if (code === 0) break;
    if (length === 1 && (type === CONSTANTS.TYPE.SHORT || type === CONSTANTS.TYPE.LONG || isBigTiff && type === CONSTANTS.TYPE.LONG8)) {
      const valueOffset = isBigTiff ? 12 : 8;
      tags[code] = readTagValue(temp, type, valueOffset, isBigEndian);
    }
    temp = nextTag(temp, isBigTiff);
  }
  return tags;
}
function determineFormat(input) {
  const signature = toUTF8String(input, 0, 2);
  const version = readUInt(input, 16, 2, signature === "MM");
  return {
    isBigEndian: signature === "MM",
    isBigTiff: version === 43
  };
}
function validateBigTIFFHeader(input, isBigEndian) {
  const byteSize = readUInt(input, 16, 4, isBigEndian);
  const reserved = readUInt(input, 16, 6, isBigEndian);
  if (byteSize !== 8 || reserved !== 0) {
    throw new TypeError("Invalid BigTIFF header");
  }
}
var signatures = /* @__PURE__ */ new Set([
  "49492a00",
  // Little Endian
  "4d4d002a",
  // Big Endian
  "49492b00",
  // BigTIFF Little Endian
  "4d4d002b"
  // BigTIFF Big Endian
]);
var TIFF = {
  validate: (input) => {
    const signature = toHexString(input, 0, 4);
    return signatures.has(signature);
  },
  calculate(input) {
    const format = determineFormat(input);
    if (format.isBigTiff) {
      validateBigTIFFHeader(input, format.isBigEndian);
    }
    const ifdBuffer = readIFD(input, format);
    const tags = extractTags(ifdBuffer, format);
    const info = {
      height: tags[CONSTANTS.TAG.HEIGHT],
      width: tags[CONSTANTS.TAG.WIDTH],
      type: format.isBigTiff ? "bigtiff" : "tiff"
    };
    if (tags[CONSTANTS.TAG.COMPRESSION]) {
      info.compression = tags[CONSTANTS.TAG.COMPRESSION];
    }
    if (!info.width || !info.height) {
      throw new TypeError("Invalid Tiff. Missing tags");
    }
    return info;
  }
};

export { TIFF };