GNOME Bugzilla – Bug 155761
Saving should update EXIF thumbnail to reflect changes
Last modified: 2004-11-17 01:06:15 UTC
From Debian bug report http://bugs.debian.org/277097 Pictures taken with a digital camera often contain EXIF information that also may include a thumbnail of the picture. When making changes to the original image, this additional data is preserved unchanged. While this is the expected behaviour for most data items, the thumbnail should be adjusted to match the changed image.
Indeed. This is related to bug #121810, but since you commented on that bug, you would probably know that.
Interesting.. re-reading one of those related bugs, it seems Photoshop doesn't change the image's thumbnail either.
I am about to commit code that allows plug-ins to register a procedure to load embedded thumbnails and GIMP is going to use that procedure (if available) in order to create a thumbnail for the Open dialog and Document History. So we better make sure that the embedded thumbnail does correctly represent the image. Raising priority on this bug.
In case anyone wants to work on this, I'd like to point at the libgimp functions gimp_drawable_get_thumbnail_data() and gimp_drawable_get_thumbnail(). One of these (probably the first one) can be used to get a thumbnail suitable for storing in the EXIF data.
The JPEG plug-in should do the following when saving a thumbnail (this is partly implemented already): Retrieve the "exif-data" parasite and in case such a parasite exists: - offer the user the choice not to save it - offer the user the choice whether to save an EXIF thumbnail or not - create or update the EXIF thumbnail if the user has choosen to save it - delete the EXIF thumbnail if the user has choosen not to save it If there isn't any EXIF data attached to the image: - offer the user the choice whether to save an EXIF thumbnail or not - create the EXIF thumbnail if the user has choosen to save one
Created attachment 33856 [details] [review] A patch for the above discussed is attached. This also reads thumbnails for the new API. This also includes an implementation for bug #158190
Created attachment 33864 [details] [review] cleaned up patch The above patch crashes instantly for me. Still, I've cleaned it up to follow the coding style. Please use the updated version for further modifications.
Fixed in CVS: 2004-11-17 Michael Natterer <mitch@gimp.org> * plug-ins/common/jpeg.c: applied (modified) patch from S. Mukund which adds EXIF thumbnail loading and saving. Fixes bugs #155761 and #158190.