Robin Strand & Stefan Gustavson have published some source-code, binaries, and documentation on a new Distance Transform algorithm that works with anti-aliased grayscale images (similar to OpenGL’s existing depthmap) rather than the super-high resolution images required by other methods. Their abstract:
We present a modified distance transform measure for use with anti-aliased grayscale images of arbitrary contours. The modified measure can be used in any vector-propagation Euclidean distance transform, and provides a much improved distance accuracy compared to a traditional binary image transform. We also modify the fast-marching method to get a smoother distance transform.
You can visit their modest website to visit the forums and read the pre-print version of the paper as a PDF.
