what should be the size in pixels of an image to make it a wallpaper in Samsung Corby

[Taylor Alison Swift]

Colours? i have a samsung Corby Colours GT-S3653 i am a huge Taylor Swift fan so i want to make her image as a wallpaper but if i put a normal picture of hers it just focuses on a part of it and it does not look good. while another picture of hers fits right in that box all by itself.! i want good pictures of her which wold fit in the screen perfectly. or even the size which is perfect.
Thanks..!