Both writeModifiedImageDataToSavedPhotosAlbum and setImageData methods in ALAsset take both image data (in the form of an NSData object) and metadata (in the form of an NSDictionary object). I've got everything working to inject additional metadata into an ALAsset that's already in the camera roll (obviously written by our app, therefore editable by it), but what I would love to do is to not have to first read the entire image data for the original just to pass it completely unmodified to either of these calls.
Is there any way to modify only the metadata of an ALAsset without paying the memory penalty of reading the entire image data? I've tried passing nil to imageData (despite this not being a documented option) and it did not work.
Berend
