1. Scanning speed
2. Document size (max & min)
One of the main factors that decide the price of a scanner is the maximum size of a document that can be scanned. Generally there are scanners which can scan either up to
A4 / legal
larger than A3
3. Feeder : Flat bed / ADF
4. Simplex / Duplex
5. Scanning Mode – Colour / B&W
There are 3 main output formats in document scanning,
- B&W / bitonal,
- gray scale
Most of today’s scanners can scan in all 3 formats. However there could be models that do not support colour scanning. (one such model is Kodak file master, a book scanner that cannot scan in colour; I think this has been discontinued now)
Also there are some scanners (Kodak – i150 and most of others) that supports dual stream outputs. That is it can scan a colour document and save 2 images in two formats at the same time. eg : B&W and colour.
(This article, “To Scan In Color Or Not?” – by Scott Blau, CEO of Datacap, provides an overview of colour and grayscale scanning.)
6. Resolutions (optical & output)
When it comes to selecting a scanner, (especially for high quality scanning) resolution is a main factor. There are two resolutions to consider.
1. Optical resolution : This represents the actual scanning resolution the scanner is capable of scanning. So this is the important measurement.
2. Output resolution : This is the enhanced or the maximum resolution that the scanner can produce using interpolation. Output resolution is always greater than the optical resolution. But It does not add more resolution but just enlarge the image by adding extra pixels artificially. So this is not an important measurement as the optical resolution.
(This article on scantips.com gives a detailed explanation on image interpolation)
7 . Drivers and capture software
Any of today’s scanner comes bundled with one or several scanning applications and drivers. There are few things to consider here.
- drivers : there are two main sets of drivers. Twain and ISIS. Twain is an open and freely available set of drivers intended for consumer level scanners. ISIS is a proprietary standard recommended for high speed production scanners. Most of the scanners support both drivers. However if you intend to use a separate specialised capture application instead of the one that comes with the scanner, you need to check on the driver compatibility. As an example the recently introduced capture tool Kofax Desktop works with Twain drivers only. Also the famous scan snap series by Fujitsu does not support both these drivers and works on a scan snap specific driver only.
- Output formats : The combination of the scanner and the capture application will decide what are the file types (TIFF, PDF, PDF/A, etc…) that can be produced.
- Image enhancements : There are interesting and very useful image enhancement features associated with different scanners. A good example is the “perfect page” features in Kodak scanners. (pdf – perfect page matrix)
- File saving options : Different scanners have different features on saving the scanned image such as the ability to directly scan in to SharePoint.
8. Specialised scanners and accessories
The last area to consider is whether you need specialised scanners such as;
- large format / high precision scanners – : kartoscan, B&H infinity
- specialised book scanners – kirtas, i2s digibook
- mobile scanners – Xerox travel scanner
- networked scanners Fujitsu fi-6010N, Kodak Scan Station 100 Plus
- Check scanners /MICR readers – MagTek
- High speed – high capacity : IBML ImageTrac, B&H ngenuity