Thanks for the pm
I'll have a look over the source code more closely tomorrow coz i'm interested in how its done...perhaps I can make a pixel shader use the same algorithm
I also found a nice article about it on wikipedia
http://en.wikipedia.org/wiki/Pixel_art_ ... algorithms
However, it seems like a weird filter to apply to a game. I mean I can understand it being used on old gameboy games where the resolution is a lot less, but I dont see why people would make a modern game and draw low resolution pictures and rely on a filter to increase the detail...I mean why not just draw a high resolution picture in the first place or use the filter on the image before loading it into the picture editor.
And the 2xSai algorithm seems to add antialising to the image...so doesn't that mean it loses its retro pixel art look?