imagecopyresampled() is same quality of imagecopyresized()

Everyone is saying that imagecopyresampled() greatly improves resizing quality due to resampling. However, I noticed that my thumbnails were very jagged and pixelated, not smooth as thumbnails should be. Even the slightly smaller images had a lot of jagged edges. The $src image is a resource of an imagecreatefromjpeg() while $dst is a resource of an imagecreatetruecolor(). Then I just imagecopyresampled() the $src to $dst. I don't think I'm doing anything wrong. Your thoughts? Thanks. -- Christopher Mobarek