I'm looking at and for libraries that can update image metadata in situ.
-StCroixSkipper
A quick look around CodeProject has at least a few such libraries.
ExifLibrary for .NET: ...You can save the Exif metadata with the image using the Save method of the class. The writer will replace the APP1 section of the original image with the modified metadata.
EXIF tag Editor for JPG images: ...First of all, I must say that there are very good articles (here on codeProject) dealing with EXIF tag reading:
* EXIFextractor library to extract EXIF information by Asim Goheer
* Cexif by Davide Pizzolato
and some others explaining EXIF tag writing:
* The ExifWorks class by Michal Altair Valasek
But as it happens most of the time, I needed a small app that would allow me to update a specific EXIF tag, and I wanted it done in C# (for learning purposes). After reading the previous articles and some other references carefully, I decided to go ahead and write a binary to solve my problems.