2007.01.22 10:45 "[Tiff] (no subject)", by Gerben Vos

Does the TIFF specification require that fields such as first IFD offset, number of tags in a directory, tag structure and next IFD offset must be written at word aligned position in TIFF file?

Yes. TIFF6 spec, page 13: "The directory may be at any location in the

file after the header but must begin on a word boundary." The layout of the an IFD then ensures that all elements are also on word boundaries.

For pointed-to data, see page 15: "The Value is expected to begin on a word boundary".

Many TIFF reading applications also accept unaligned data (maybe with a warning), but you shouldn't write such TIFFs.

There is no such restriction for the image data pointed to by the StripOffsets field.

Gerben Vos.