Scanning is the process by which an image is converted into digital information. Unlike photocopying, scanning does not simply make a reproduction of an image, but must convert the image into a different kind of information as well.
The first scanning technology was developed back in the 1930’s, and the first picture was scanned in 1957. The earliest scanners were drum scanners, which were followed by hand-held scanners, flatbed scanners, and finally, 3D scanners. Although drum scanners are still used today, flatbed scanning is the most common scanning technique used today.
Drum Scanners
Drum scanning was the earliest type of scanning, and the technology is still used today to scan images that need to be of extremely high quality. Drum scanners use photomultiplier tubes, which are very expensive, but allow for high quality images. Photomultiplier tubes are tubes that use a vacuum in order to allow electrons in light to be multiplied, and so develop a higher quality reproduction of an image.
Hand-held Monochrome Scanners
Although more popular in the 1980s and 90s, hand held scanners are also still used today. Though their popularity has fallen in favor of flat-bed scanners (because hand-held scanners are often monochrome and produce a lower-quality image) and because they require a steady hand.
Flatbed Scanners
Flatbed scanners were developed after hand-held scanners and became popular because they allow for better image control. Instead of forcing the user to hold the scanner, they allow whatever is being scanned to be set down and remain stationary while scanned. Obviously flatbed scanners are not as portable or versatile as hand-held scanners, so the earlier technology remains popular for some uses.
Planetary Scanners
Planetary scanners are basically scanners that use a digital camera in order to scan an object from a distance and not damage it with direct contact – they are often used to scan rare or delicate objects such as old books.
3-D Scanners
3-D scanner technology seems similar to planetary scanning technology but is slightly different. A 3-D scanner will analyze an object, an analysis which is sometimes based on taking many different images from different sides of an object, and then reconstructing a 3-D computer image of the object. Where as Planetary scanners often take images from one perspective, 3-D scanners may use different methods (such as triangulation) and different perspectives in order to determine the shape of an object.
3-D scanning is becoming more and more important in the modern world. It is not only used for 3-D modeling, it is also used heavily in computer graphic design, as well as in engineering, where it is often used as a tool for reverse engineering. Besides those uses, 3-D scanning is an important part of 3-D printing, or additive engineering, which is a technology that is poised to take the world by storm.
Being able to turn an image into digital information is clearly a revolutionary technology that may take us far beyond simply scanning our personal photos. Because of technology like this and the inventors and scientists that developed it, the future is an exciting place.
As a writer and computer enthusiast, David Rocke was helping his friends program their computers and protect their documents for years before he became the resident blogger for Vanguard Archives of Chicago.
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