2004.06.09 14:41 "[Tiff] TIFF validation", by Fernando Loygorri

I have some questions regarding validation of TIFF files.

Page 21 of the 6.0 specification indicates that the type of the ImageWidth field is "SHORT or LONG". To me, this seems to indicate that if I'm validating a TIFF file and I find that the ImageWidth field is of type BYTE I must flag the file as not valid.

On the other hand, page 16 of the same document says: "TIFF readers should accept BYTE, SHORT, or LONG values for any unsigned integer field." To me, this seems to indicate that in the example above I must consider the file valid.

But, then, why does the document explicitly exclude BYTE as a legal option in the definition of the ImageWidth field (and many others)?

I'm aware that "should" implies a recommendation (page 12); does this mean that the note on page 16 has no bearing on the validity of a TIFF file and it just exhorts writers of viewing software to try to do the best they can when faced with a malformed TIFF file?

Comments?

FGL