error with Tiff files due to libTiff?

[Hubert Figuiere]

On Wed, 2008-06-25 at 17:27 +0200, Augur wrote:
> First, I generate a foo.tif file (eg. with gimp), with no meta data.
> Then I execute my little application, Xmp meta data are added in the
> tiff header. The problem comes when I try to execute my application
> again (or try to use any external application using LibTiff), when
> reading foo.tif, I've got the message: "TIFFReadDirectory: Warning,
> foo.tif: wrong data type 7 for "Photoshop"; tag ignored.". It is just
> a warning, the image is still correct.
> 
> Do you know this issue? Is it a bug from libTiff, or a problem when
> Exempi write Xmp meta data to Tiff file?

IMHO it is safe. It is just that the XMP code (from Adobe) seems to
write this "Photoshop" tag with and "UNDEFINED" type while libtiff
expect it to be "BYTE". I guess there is a bug in there, but I'd not
worry unless you really need this field. Actually, here, I also get a
warning for "RichTIFFIPTC"

If you find that's important, feel free to file a bug. It shouldn't be
too hard to fix.

Hub