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Bug 158192 - add thumbnail loader for TIFF images
add thumbnail loader for TIFF images
Product: GIMP
Classification: Other
Component: Plugins
Other All
: High enhancement
: 3.0
Assigned To: GIMP Bugs
Depends on:
Reported: 2004-11-13 17:35 UTC by Sven Neumann
Modified: 2018-05-24 11:16 UTC
See Also:
GNOME target: ---
GNOME version: ---

Description Sven Neumann 2004-11-13 17:35:34 UTC
A recent addition to the GIMP 2.2 API allows plug-ins to register an additional
procedure to give access to a thumbnail embedded in an image file. The TIFF
format allows for such thumbnails so it would be nice if the TIFF plug-in would
provide this functionality.
Comment 1 Sven Neumann 2005-05-13 13:40:41 UTC
I had a closer look at the TIFF spec and unless I missed something, the TIFF 6.0
spec doesn't define thumbnails in TIFF files. I have come across two other links

- describes a tool that
  creates thumbnails using a SubIFD tag (#330). This is described in more detail

- describes an
  extension to the TIFF format that is used by Photoshop. The data seems to be
  in the same format as used in the PSD format (see bug #158234).

Comment 2 weskaggs 2005-05-13 15:18:34 UTC
I recently had occasion to use PS on a Mac (not sure what version, but recent),
and found that when I saved an image in TIFF format and then opened it later in
GIMP, the thumbnail showed up as a separate tiny layer.
Comment 3 Sven Neumann 2005-10-24 16:36:07 UTC
The thumbnail is most probably stored as a separate image in a TIFF image
directory then. That isn't really what image directories were designed for
though and I would prefer that we use the SubIFD tag as described above.
Comment 4 weskaggs 2006-05-20 21:55:28 UTC
Bumping to Future because this is not a blocker for 2.4.
Comment 5 theonlychurch 2009-05-19 12:23:21 UTC
Gimp-2.6 still reads TIFF thumbnail layers as if they were corrupt. I extracted the thumbnails using other software like exiftool and they are fine, so its a Gimp bug. The TIFF/EP spec describes them.

It would also be good if Gimp didn't automaticall suffix the filename with "-1-of-2-pages". It's a pain having to remove this from the filename of every thumbnailed TIFF image I edit.

showFoto (from digiKam) is an example of a program that saves these thumbnails.
Comment 6 Michael Schumacher 2009-05-19 19:54:52 UTC
Please do not mix different issues in one bug report.
Comment 7 Michael Natterer 2013-10-29 23:14:20 UTC
This should now be easy to implement using
gimp_image_metadata_load_thumbnail(), setting milestone
to perhaps attract some attention.
Comment 8 michal 2013-11-18 19:46:30 UTC
I would love to take this quest. Im new to open source and "how all this works". I've  subscribed to for more information.
If there is anything else I should know please email me michal.g.buras at
I want to get started as soon as possible.
Comment 9 Michael Natterer 2013-11-19 11:24:14 UTC
In plug-ins/common, grep for gimp_register_thumbnail_loader() and deduce
what needs to be done in the tiff plug-in.
Comment 10 michal 2013-11-19 17:21:15 UTC
i ran i little problem while compiling gimp sources on fedora 19 KDE, some of the dependencies form native fedora repos are outdated, ill probably figure that out in few days (due to beeing a student in the middle of semester) , and give you some serious feedback in the end of the week.
Comment 11 michal 2013-11-21 23:25:46 UTC
kk copiled, found the method you mentioned above, wroking on it.
could anyone supply me with a valid tiff image with embedded SubIFD thumbnail?
the only one I could produce on my linux was the one from gimp, and had to make it from jpg with thumb and then export to tiff.
Comment 12 michal 2013-11-22 17:10:36 UTC
tried to use thumbnail from tifflibrary to create one but it writes only 8byte header without any data, so i im kind of stuck without a good example of a tiff file with a thumb.

i could create one from scratch,but i need some things explained.

Do the  2 first bytes of IFD contain number of entires (tags with values) without the last entry which is the next IFD offset?

Do entries need to be in ascending order, with next IFD  OFFSET at the end?

So Im supposed to put a subifd tag in the IFD pointing to IFD containing thumb and that will be a proper tiff image ?
Comment 13 Michael Natterer 2013-11-22 18:47:42 UTC
From your comments it looks like you are the most competent guy in this
area now, don't expect  much explanation :)

Also, I noticed that we seem to write EXIF-only thumbnails with the new
metadata code, perhaps that needs to be changed too...
Comment 14 Jehan 2016-06-11 12:27:49 UTC
michal > this has been nearly 3 years, so is there a chance you are still around and that you finished (or nearly finished) a patch for this? :-)
Comment 15 Jehan 2017-03-24 02:33:55 UTC
No patch came in and that doesn't count as blocker. Let's just bump to 3.0 milestone.

As usual: if someone wants to push the feature, patches are welcome and would be integrated for 2.10 if they come on time.
Comment 16 GNOME Infrastructure Team 2018-05-24 11:16:41 UTC
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