Scanning is not just a simple physical process. Unless you are scanning a standard document that is crisp and clearly printed (preferably in black ink on white paper), you might need to make some adjustments to get just the result you want. The result you want can be:

• A scanned image that is more legible than the original document in a poor condition or with poor contrast (say, blue ink on a dark colored paper)
• Scanned images to be used for subsequent printing, or for Web pages or in emails
• Scanned images that reveal greater detail than what the human eye could see on the original

Let us look at the kind of adjustments that can produce desired results.

Adjustments to Improve Document Quality

Adjusting brightness and contrast can often produce results that are better than the original. Adjustments are also possible for color, exposure etc that too can produce better results.

You can also work with the original document to get better scanned images. For example, you can iron out the folds in a much folded document so that it lies really flat on the scanner bed. This can avoid distorted characters.

Other precautions include scanning with the correct orientation appropriate for the document. Scanning a landscape oriented document with a portrait orientation and then rotating the image for correcting the orientation can lose some detail.

Details can also be preserved better if you scan only those portions of the original document that you need for your purpose.

Selecting the Output Type

You can set the scanning software to produce scanned images in different formats. A TIFF format reproduces details and is suitable if you want to print the scanned image. The price for this kind of detail is larger file size.

If you are planning to upload the scanned image to a Web page or use it in an email, you can do with much less detail. A compressed file format such as JPEG is adequate in these cases.

Selecting the Resolution

Resolution is measured in dots per inch (DPI). The more the number of dots, the greater the detail you get. The following is a rough guide to help you select the right resolution.

• Select a 1200×1200 dpi (or 1.44 million dots per square inch) resolution if your intention is to use the image in emails and or Web pages. Some loss of detail is okay in these cases.
• A 1600×3200 dpi (or 5.12 million dots per square inch) resolution shows the image in the same way that the human eye sees the original.
• If you want to enlarge and study fine detail, select a 2400×4800 dpi (or 11.52 million dots per square inch) resolution.

Web Pages and Emails

Actually, it is ppi – pixels per inch – that matters when you work with Web pages. Divide the screen width in pixels by the picture’s length in inches to get the ppi. Then save the picture with that ppi.

For emails, very small size files are important, and it is best to save any pictures at 72 or 100 dpi.