Bitmap fonts are simply collections of raster images of glyphs. Raster or bitmap files store images as a group of pixels. Vector graphics formats are complementary to raster graphics. Inkscape supports image tracing, the process of extracting vector graphics from raster sources. Canvas provides tools for creating and editing vector and raster graphics. Graphical terminals are divided into vector-mode terminals, and raster mode. Laser engravers using this technology can work in either raster or vector mode. It is capable of describing the rendering of vector and raster data. The most significant bit of a line of raster data represents the leftmost pixel. XPS supports HD Photo images natively for raster images. OpenRaster is an XML file format used for saving raster graphics. Computer printers create their images basically by raster scanning. See also digital raster graphic and History of web mapping. Level 3 PostScript adds further transparency option for any raster image. Inkscape uses a (built-in) potrace to import raster image formats.