How to get / set jpeg exif data with objective c - mac os

Currently trying to extract and manipulate the exif (or whatever meta data a Canon camera produces on an image)

Is there any specific library that I can use to process this data?

Note: Am not developing an ios app, mac os to be specific.

Thanks!

Solution

http://libexif.sourceforge.net/ appears to be a common C library for exif data. (First result on Google search for 'exif c')

There seems to be a few C++ libraries, but no pure Objective-C that I could find easily