Document Imaging Scanning
Adjusting the color and resolution
Document imaging scanning is probably the most common use for a scanner. There are two basic settings that you need to adjust. The first is the color setting. There are typically four choices. These are:
Choosing the color setting• 1-bit black and white
• 8-bit grey scale (in other words, 256 shades of grey
• 8-bit color (256 colors).
• 24-bit color (16.8 million colors)
Obviously, the increasing color ranges result in increasing file sizes too, but for large file especially, it is worth using JPEG as means of compression. 24 bit coloring gives a more photorealistic look, but the vast increase in file size between that and the 8 bit alternative may mean you settle for the simpler option. If you are planning on uploading the scanned image to the internet, the 8 bit option is probably the best option – even with broadband, large 24 bit images are painstakingly slow to load. However, if the file is not to be used over the internet, a 24 bit scan saved as a JPEG will provide a better result than an 8 bit scan.
Choosing the resolution
The second setting that you need to adjust is the resolution. By choice, we would all probably hope to scan all our images at the highest resolution and with the best color choice, but this will lead to a file size that is so large that the scanning software will struggle to cope with the demands. Therefore, the resolution of the picture is often compromised purely as a practical measure. The only way to work out what resolution to use is to experiment with the various options until you find a resolution in which you can get the most out of the image without the size of the image preventing you from working with it. It should be stated that for small images, a high resolution will gain you very little as there is not much to zoom in to in the first place. In this situation, it is better to choose a lower resolution with a higher color scale.
Most flatbed scanners are designed for A4 images and documents. If the image you are hoping to scan is larger than A4, you should ask at your local copy shop to see if they offer scanning facilities. Domestic flatbed A4 scanners can be purchased for less than $70, but large format scanners cost thousands of dollars. If you are looking to buy a large format scanner for your company, you should carefully consider every aspect of your decision and make sure you get professional advice and sample scans from potential retailers.