White/grey outlines on PNG sprites

When I display a png sprite I get a grey/white outline around it. This outline appears to be semi transparent. I'm 100% it is being added by Blitz and not with the PNGs because when scaling the sprites the line stays the same thickness. So small sprites it is very obvious but barely noticable on larger ones.

Is there any fix or way around this?

Run your PNG through this.

Brilliant worked perfectly!

Thanks a ton =)

The way to avoid this when drawing your sprites is to make sure that the alpha edges (where alpha goes from >0 to 0) are not coloured white but coloured the same as the pixels next to them.

Normally you wouldn't see these white/grey pixels but because of bi-linear filtering they bleed very slightly into the edges of the sprites.