There is an easy but little known way to store many kinds of UIKit objects in CoreData without writing any code. It works for UIImage, UIColor, UIBezierPath, MKPlaceMark, NSDate, and any other class that conforms to the NSCoding protocol.
What you need to do is set the attribute type to Transformable.
Now can set UIImage objects directly into your NSManagedObject objects:
person.thumbnailImage = [UIImage imageNamed:@"defaultPortrait"];
anImageView.image = person.thumbnailImage;