evince−thumbnailer − create png thumbnails from PostScript and PDF documents
evince−thumbnailer [−s size] input output
evince−thumbnailer is a GNOME program to create thumbnails from PostScript (PS), Portable Document Format (PDF), DjVu and DVI files.
evince obeys all normal GNOME and GTK+ command line options. The only option −s size makes it possible to choose the vertical size of the created thumbnail.
evince(1), gnome−options(7), gtk−options(7).
http://www.gnome.org/projects/evince/