Get the Big Picture30 Jun, 2001 By: Michael Lennox
Four large-format scanners support color copying
For some CAD users, a large-format scanner is as indispensable as a printer or plotter. Traditionally, large-format scanners are used for archiving paper drawingsreplacing those flat files with digital files. In GIS applications, large-format scanners are used to scan existing maps or aerial photographs. Those who use CAD for large-format design or CAM applications also use this technology. Though these industries include the heaviest users of large-format scanners, all CAD departments should consider the benefits of using them as part of a copy or scan-to-print system.
Four companies provided scanners and software for review: Contex, IDEAL, Océ, and VIDAR. With respect to hardware, IDEAL, Océ, and Contex are all nearly identical. Outside of cosmetic variations, the differences are most apparent in the softwareit is the key component to the entire scanning system.
Each scanner is an integral part of a larger system that includes the software used to capture, manipulate, and store the scanned image. These are key elements if you want to archive legacy drawings or use a scanned document in your CAD software. You can use scanned drawings in raster form, in which each element consists of small colored blocks called pixels, or you can convert them to vectors using raster-to-vector conversion software (see the CADALYST Labs review). None of the systems reviewed include raster-to-vector tools. They do provide copy software to support a scan-to-print system. If you have a large-format color printer, you already have the output end of a large-format color copier.
How we tested
We set up each scanner with its base options and tested each using the same Windows NT 4 Pentium IIIbased system with 128MB of RAM and an Adaptec 2940 UltraSCSI adapter. I scanned a D-size (22" X 34") map at 24 bits and 400dpi into each. Scanning speeds were affected by software and the amount of physical system RAM. Times don't include saving the file to disk. Some scanner manufacturers sell software or firmware-based upgrades to accelerate scanning times.
Reviewer's Report Card