Pixel perfect sprite rendering

Hey guys. Has anyone else encountered issues with getting sprites to render pixel perfect on the canvas? I've made an image to show what I mean:


On the left is the source image. On the right is a screenshot of the same icon, rendered through uGUI. So I've been going through the checklist - yes the sprite is exactly the native resolution, at an integer coordinate, and the canvas is pixel perfect. Any idea what could be causing this blurriness?

 

http://forum.unity3d.com/threads/blurry-graphics.265395/#post-1754009

This post has put the problem much better than me, and also provided evidence that switching to point sampling (while improving things) creates a pretty untenable number of artifacts.