text: Character-by-character computer-aided phototypesetting was in turn rapidly rendered obsolete in the 1980s by fully digital systems employing a raster image processor to render an entire page to a single high-resolution digital image , now known as imagesetting .
simplified: Character-by-character computer-aided phototypesetting was , in turn , rapidly rendered obsolete in the 1980s by fully digital systems . Those systems use a raster-image processor to render an entire page to a single high-resolution digital image , now known as imagesetting .