Once a drawing is scanned from a raster (dot format), it can then be vectorised giving you either a DXF or DWG file, which can then be imported into your CAD package.
Vectorisation, is the process of converting a computer program from a scalar implementation, which does an operation on a pair of operands at a time, to a vectorised program where a single instruction can perform multiple operations on a pair of vector (series of adjacent values) operands.
