I had the moderator comment that the screenshot was a low quality/blurry image.
and I want to say the following:
-the image was taken from the h264 encode and noise was removed completely and sharpened.
-the image was then "double layered" and applied various lighting effects since it looked dead, and dark.
-the "blending" of images also included a type of "glow" on the second layer, which could be the "blur", but then again if you look at the background image its just windows, stairs and a couple of silhouettes.
-If you zoom in on the silhouettes they dont look blurry at all, you can easily find the edges on senjougahara's body and araragi's silhouette is as good as I could get from the h264 encodes in HD
-I took enough time to consider details and I believe the wallpaper is good as it is.
quickie:
http://i21.photobucket.com/albums/b256/David606/Bakemonogatari.jpg
full size:
http://i21.photobucket.com/albums/b256/David606/Bakemonogatari-1.jpg