I quote, from the product brochure, which can *EASILY* be found on the Toshiba website...took all of about 60 seconds to find it.
"Video Upconversion - 720p/1080i - HDMI can support uncompressed digital video up to HDTV level resolution. Thus, the player makes use of this conduit by up-converting the standard DVD picture resolution to nearly HDTV-quality with output resolutions of 720p or 1080i. This makes a DVD player with an HDMI™ connection the perfect match for today's digital televisions. And because this conversion is performed in the player, the signal remains free from excessive digital-to-analog conversion artifacts."