Dani Lischinski's page: http://www.cs.huji.ac.il/~danix/
Johannes Kopf page: http://johanneskopf.de/
> This paper introduces a novel content-adaptive image downscaling method. The key idea is to optimize the shape and locations of the downsampling kernels to better align with local image features. [...] Besides natural images, our algorithm is also effective for creating pixel art images from vector graphics inputs, due to its ability to keep linear features sharp and connected.
IIRC, this is one of the major reasons that vector graphics based icons have not taken off.