Who would want to do this LOL???
Usually resolution is converted upward from standard-definition to 720p or 1080p high-definition resolution. In the case of Atlona's AT-HD530, the down-converter changes high-def video content to standard-def. The unit accepts high-def sources over HDMI or DVI inputs, converts it, and then sends it to a standard-def display over composite or S-video outputs including any accompanying audio.
The AT-HD530 not only accepts 1080p video content from HDTVs but also UXGA (1600 x 1200 pixels at 60 Hz) content from a Mac or PC. Also, both NTSC and PAL signals are supported so the AT-HD530 is good to go in North America or Europe.