Scanned drawings are in a raster to format. Raster drawings need to be converted to vector format in order to import them into a CAD system. There are several different methods that can be used to convert scanned drawings into CAD.
One method is heading up digitizing. Heads up digitizing is probably the simplest form of raster to vector conversion, although not necessarily the best or the most accurate. In heads-up digitizing, scanned images are traced by creating design file elements on top of a scanned image. This allows scanned images to be converted into a CAD file. Often, you may be able to selectively trace only the portion of the image that interests you, or you can redraw the entire image. Another method is to use commercial raster to vector software, which often enables the user to do “automatic raster to vector conversion.” Software such as this traces lines automatically from the scanned raster image using image processing and pattern recognition techniques. The idea behind automated raster to vector conversion algorithm is to let the computer do the actual line tracing and eliminate tedious manual tracing the human operator has to do. Some companies use custom written CAD conversion scripts and software, designed to solve particular problems that they regularly encounter with their raster to vector conversion. The important thing to realize is that “best” method is the one that provides the best end result. And, that may be any one of the methods mentioned above, or a combination thereof. This is one place where a professional raster to vector conversion service has the benefit of experience to determine the best raster to vector conversion process for any particular drawing or set of drawings.
CAD Perfect TM files are guaranteed to provide perfect CAD drawings with real lines, arcs, circles, and text as text, produced at a minimum of 3-7 layers (levels) and colors.