Using ALAssetsLibrary and ALAsset take out Image as NSData

Question

I wish to extract the image using ALAssetsLibrary and ALAsset directly in the form of a NSData object.

Using a NSURL I take out the image in the following manner.

Answer 1

UIImage * selImage = [UIImage imageWithCGImage:[asset thumbnail]];       
NSData *baseImage=UIImagePNGRepresentation(selImage);