Diffuse is very similar to Adobe Photoshop’s own diffuse filter with a key difference – it supports sub-pixel (fractional) diffusion. This key feature takes the diffusion effect to a whole new level and now makes it useful for production where antialiasing effects are necessary.
Adobe Photoshop’s integer-based diffusion algorithm produces harsh aliasing seldom useful for any kind of professional work. By using sub-pixel diffusion, the results are subtle and fully integrated within the image. Applying several iterations of the effects at one time produces even more pleasing results. Sub-pixel diffusion means you can apply diffusion values less that 1.0 pixel.