Does ExifTool limit the size of return for a given tag

[carlseibert]

Hi,

I have been given some Tiff files with bloated xmp-photoshop:documentancestors tags. When I read these files, I get a few screenfulls of returns for that tag - about 1,000 hex values, or about 40KB of text.

When I blank that tag (-xmp-photoshop:documentancestors= ), the file size shrinks by about 30 MB!  And I receive a warning that says "Warning: [minor] Excessive number of items for photoshop:DocumentAncestors. Processing may be slow -"

I wonder if ExifTool is just limiting the amount of type it returns for the tag to something reasonable and there really is 30 MB of nonsense in the tag, or if something really odd is going on.

Apparently, some circumstances are causing Adobe Photoshop to occasionally write files with this tag corrupted. A number of people have reported experiencing the problem, but AFAIK, nobody has been able to replicate it yet.

Thanks,

-Carl

[Phil Harvey]

Hi Carl,

I wonder if ExifTool is just limiting the amount of type it returns for the tag to something reasonable and there really is 30 MB of nonsense in the tag,

You should see a warning like this when extracting:

   "Extracted only 1000 photoshop:DocumentAncestors items.  Ignore minor errors to extract all"

- Phil

[carlseibert]

Doh! Thanks! You're absolutely right. The warning is right there. I guess I was just dazzled by the 1,000 Document Ancestors. :-)

[Phil Harvey]

I guess I was just dazzled by the 1,000 Document Ancestors. :-)

Understandable.

- Phil

[Stephen Marsh]

This topic is related and may also be of interest:

https://exiftool.org/forum/index.php/topic,8247.msg42292.html#msg42292