What is a Scanned Raster Image Drawing?
A scanned raster image is a digitized image of a drawing taken either from a paper copy or microfilm copy of the drawing. A scanned raster image places small black dots, called pixels, where it recognizes a contrast between the normally white paper background and the pencil or ink markings. A typical drawing can have millions of small black dots, or pixels, representing these markings. This technology is similar to making a Xerox photocopy on paper using an office copy machine, a process that most of us are familiar with. The main differences are that drawings can be much larger than the 8-1/2″x11″ paper and instead of placing the image immediately on a blank piece of paper, a digitized image is placed in a computer file that can later be viewed, edited and printed by a computer program. Normally each of these dots is one color (black) and raster files can get very large if uncompressed. If color is added to each dot, these raster files can become exceedingly large even when compressed
