Geotagging JPEG with Core Foundation

I was searching a way to edit or add GPS metadata of JPEG files without using an external library inside a Mac Application. After looking on internet and reading the ImageIOKit documentation, I found an interesting post on the Apple Mailing List talking about this topic and an old bug related to it. It includes a code sample that is apparently working now (Mac Os X 10.8).  I just wanted to add some details about it :

• The values corresponding to the kCGImagePropertyGPSLatitudeRef/kCGImagePropertyGPSLongitudedRef keys are expected to be of type NSString.
• The values corresponding to the kCGImagePropertyGPSLatitude/kCGImagePropertyGPSLongitude keys are expected to be of type NSNumber.