As the name suggests, the blurring at the edges of the fractal objects in this image was intentional. It was part of the original render, in Bryce 3D. No post-rendering was done, except for minor contrast adjustment and addition of copyright.
For anyone wanting the technical info: This image is comprised of several symetrical lattices. A black and white version of the fractal was used to create them. A color version of the same fractal was then mapped onto them. I distorted the shape of the lattices slightly. This is what caused the blurring at the edges. Anti-aliasing was set at fine art. All objects and textures are dwarvenkind originals.