Low Resolution

I just uploaded your plugin and set some high res png images in the gallery and they are pixelly. Is there a way to fix this? Here is the link so you see what I mean. I tried using 850×600 and 1771×1250 image size and neither made a difference. Here is the link for you to see what I mean:

http://threesummerscreative.com/happy-holidays/

Thanks for your help!

http://wordpress.org/extend/plugins/image-parallax/