TWAIN and WIA are standards for communicating between imaging devices (e.g. scanners) and software applications.
TWAIN
If you have a scanner and it is “TWAIN compliant”, you can use it to scan directly into any software application that supports TWAIN, like our Scan2CAD raster to vector conversion software. This means that after you scan, the scanned image will appear in the application already open.
When you scan using an application that supports TWAIN, the scanning dialog and the options it contains are specified by your scanner’s manufacturer (Canon, Epson, HP, Contex, Graphtec etc.) and will therefore vary depending on the type of scanner you have.
TWAIN scanning dialogs can be extremely comprehensive. For example, the TWAIN interface supplied with Contex SD and HD large format scanners is an exact replica of Contex’s NextImage scanning software minus the print, copy and color management components. If you have a Contex scanner and all you want to do is scan technical drawings, Contex’s free TWAIN interface will do everything you need.
“The word ‘twain’ is an archaic form meaning ‘two’. It appears in Kipling’s ‘The Ballad of East and West’ – ‘… and never the twain shall meet …’, reflecting the difficulty, at the time, of connecting scanners and personal computers. It was up-cased to TWAIN to make it more distinctive. This led people to believe it was an acronym, and then to a contest to come up with an expansion. None were selected, but the entry ‘Technology Without An Interesting Name’ continues to haunt the standard.” (From the Free On-line Dictionary of Computing.)
WIA
WIA (Windows Image Acquisition) is a Microsoft utility that is supplied as part of Windows. Like TWAIN, WIA allows you to scan directly with a “WIA compliant” scanner into any application that supports WIA or TWAIN – all TWAIN compliant applications like Scan2CAD raster to vector conversion software support WIA as well.
Unlike TWAIN, however, the scanning dialog that appears when you scan and the controls on it are variations on a basic Microsoft design. This means that the level of functionality and scanning control that are available in a WIA interface are less comprehensive than in a well-written TWAIN interface.
Colortrac large format scanners support WIA rather than TWAIN. If you have a Colortrac scanner we suggest you purchase Colortrac’s (excellent) ScanWorks scanning software rather than attempt to use the WIA scanning interface.
Which scanners support TWAIN and WIA?
To the best of our knowledge all desktop scanners support TWAIN and WIA, as do most modern large format scanners. For example, modern Contex and Graphtec large format scanners support TWAIN, and modern Colortrac scanners support WIA.
However, if you have an older large format scanner, it is unlikely to support TWAIN or WIA. In this case you will not be able to scan directly into TWAIN/WIA compliant applications such as Scan2CAD raster to vector conversion software.
If your scanner doesn’t support TWAIN/WIA and you want to get scanned images into a TWAIN/WIA compliant application you need to use the software supplied with your scanner to scan your drawings, save them as TIFF, BMP or similar, then load the saved scan into your application.
Alternatively, there is a German software program from SCP called EasyTWAIN that makes non-TWAIN compliant scanners TWAIN compliant so you can use them to scan images directly into your TWAIN compliant software applications. EasyTWAIN supports a wide range of older large format scanners.
