No Experience Necessary - Part 5
This week's article takes a look at scanners, how they work and the kind of things you can do with them, including OCR - Optical Character Recognition.
What is a Scanner?
A scanner comes in three basic forms - a flatbed, handheld or as part of a printer/fax machine. They are used for getting information that is on paper (usually pictures), into your computer. Once there, you can edit and change the scanned image to heart's content. Scanners can be black and white only or - more usually these days - in colour.
As mentioned, most scans are graphics (pictures) and commonly these are photographs or drawings made on paper. This means that a scanner can be used for:
· Scanning photographs
· Scanning drawings
· Scanning your signature so that standard letters can be printed to include your signature (great for producing mailing lists where you do not want to personally sign every letter)
· Creating personal menus, invitations or letterheads where logos are scanned into the computer. The whole item can then be printed (works great on colour printers!)
· Scanning in text which can then be turned into text within your word processor. (This is OCR - more on this later)
In fact, the more you use a scanner, the more ways you will find to use one!
How does a Scanner work?
All scanners work in much the same way. A strong light is passed over the image. Light is reflected back from the surface which is picked up by sensors which measure the intensity and colour reflected back which is then converted into a "strip" of colours (a bit like a line of text only in this case - a line of colour). The colour black reflects no colour so the scanner will register this and "print black."
The scanner head is then moved down so that the next "line of colour" can be scanned. This process is repeated until the whole image is scanned. Once complete, the scanner software will then translate the information into a graphic (picture) which is transferred from the scanner to your screen.
This is where the different types of scanner become important. With a flatbed or "printer" scanner, the scanner itself moves the scanning head down. This ensures a smooth, seamless movement and produces the best results.
A hand held scanner relies on YOU to move the scanner head. Although good scans are possible, it does require a bit of skill and practice to do this. Move too fast and the scanner cannot keep up resulting in smudged or blurred images to be created. Unless you are into weird art forms, this is not usually wanted. Hand scanners are cheaper as they don't have a motor to move the scanning head.
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