Nicola,
Well, you've accomplished something that wasn't so easy according to him!

Apparently forming the words "Happy Birthday" isn't easy for him either! My father is a strange one. He'll go out of his way to help someone in a major way but he won't say "Happy Birthday" either. Quite honestly, I don't say it to him either. Not to get even or anything like that. It would just seem awkward since he's never verbally expressed any positive emotion to us himself.
Oh, I did shrink the original photo for you and re-attached it but I have a large monitor with a high resolution so I suppose I didn't shrink it enough to be noticed at a more "normal" resolution.
You did a good job! Next thing you know, you'll be doing graphic art. The world is your oyster and you are the pearl.
Craig