Scanners

Key Components
Choosing the right scanner involves a number of different criteria, none more important than bit depth, resolution, dynamic range, and color. While the reason for buying a scanner and what you intend to scan are key decisions to consider, these four components will affect the quality of a scan regardless of how it is used in the office.

Bit Depth
When a scanner reads an image, it breaks down what is read into small dots, or pixels. Based on the quality of the machine, a scanner can record varying amounts of information about each pixel. The amount of information that the scanner can remember about each pixel is commonly referred to as bit depth.

A scanner with a bit depth of one can only distinguish whether a pixel is white or black, with each increase in bit depth representing an ability to record more details about an image's color or gray scale.

For black and white scans, a 12-bit scanner will usually provide adequate reproduction of over four thousand shades of gray. Bit depth for color scans can be broken down by how many bits the scanner can process for each primary scanning color - blue, red, and green.

An eight bit scanner can identify 256 colors for each pixel; a 24-bit scanner can reproduce 16.7 million colors. For most business purposes, a 24-bit machine is sufficient.

There are also scanners on the market at 30- and 36-bit depths, which is more color than the human eye can distinguish. While most software systems today cannot accurately process the billions of colors that come with such high bit-depths, the extra information helps to clean up images that may be affected by noise or other losses in the image transfer. In turn, those seeking the highest quality of color reproduction should look into 30- or 36-bit depths instead of 24.