Digital raster graphic(DRG) and digital line graphic(DLG) are two digital maps that can be taken cheaply, and DLG is a commonest data format now, it is the main data source of GIS.

The algorithm foresees the pixels which will be activated in a raster line and implements parallel filling pixels.

The different information is implemented to clear and steadily display by using of time-shared display with line by line scanning and interlaced scanning in a raster picture.