progressive JPEG Unlike normal JPEG images, which are displayed one line at a time from top to bottom, progressive JPEGs are displayed in alternating lines, then filled in on a second pass. Depending on which graphics viewer or Web browser is being used, progressive JPEGs may produce a "venetian blind" effect or simply a blurry or blocky image that gradually sharpens. Pages using progressive JPEGs let people see at least the outline of an image sooner, and often appear to load faster than pages using normal JPEGs. Although progressive JPEGs are fairly new, most modern browsers support them. If a browser does not support progressive JPEGs, it simply displays the image as a normal JPEG. See also: interlaced GIF, JPEG