The Scanner

From Picture to Digital Image

Learn about the scanner, and how this device will fade into history.

Episode #4-21 released on February 9, 2014

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The Image Scanner, the answer to the question on how do you get that text, picture, or drawing into your computer to share with the world. It is important to note that even if the digital camera has taken over most of the tasks we used a scanner for, the scanner still has it place in any place that does photo processing, image scanning, etc... While, we use scanners less, we still keep them around.

The scanner is a descendant of the early telephotography and fax input machines, which made facsimiles of the original either locally or over the wire. These images were of poor quality, but still allowed for others to receive a reasonably recognizable recreation of the initial image.

The modern scanner uses 3 rows CCD arrays, short for charge-coupled device, the sensors detect red, green and blue using filters and are combined to recreate the image. The RGB data received from the CCD array has to be processed by a proprietary algorithm to correct for different exposures. The resulting image is sent to the computer via USB, SCSI or Parallel Port.

The CCD array in your typical scanner is usually fixed, but to be able to scan photos and other documents it needs to have a movable mirror and light source which is normally a xenon, LED, or cold cathode fluorescent light which illuminates the document from underneath the platen, usually made of glass. The moveable light and mirror are usually moved with the help of a rubber flexible gear in the shape of an elongated loop. A control rod is also positioned to maintain the correct distance from the glass and to have an even, in focus, scan of the document or photo.

Now, that we understand how it works, why is this device still relevant today?

Let's start off with the scanner's principle competition, the digital camera. The digital camera is portable, the scanner isn't. We have cameras on virtually all modern cellphones, scanners would make our phones too bulky, and because we always have our cellphones, we benefit from the fact that our phones are always accessible and ready to use. Most scanners require a computer to function. However, a photo from a digital camera can be dull, lack contrast, be out of focus, be too bright or dark, etc... Most high quality print outs that we may be tempted to take a picture of, instead of scanning, will return with reflections, where scanners don't. Scanners can output to lossy or lossless formats, most digital cameras people own are in cellphones and only save to lossy formats. The scan will always be in focus, have great contrast, and won't be too bright or dark. Some scanners, can also, scan negatives, no digital camera on a cellphone can ever achieve that without help.

Will the scanner ever be made irrelevant?

Yes. The age of the photo negative is pretty much dead. And, while taking a photo of a photo is ridiculous, most of us share our photos online, so we have access to the digital original. Some digital cameras can take 3 dimensional photos of objects, something most home scanners can't dream to be able to do. We, are, also, part of the mobile revolution, so anything too bulky is usually not good for business or pleasure. In short, the scanner will give way to the digital camera, as the technology becomes better and better at capturing still images, and due to the fact that we print less and less documents to begin with. Because, the scanner is only useful from a specific set of tasks, and those tasks are becoming more and more rare, the scanner will become more of a novelty than a tool.

Host : Steve Smith | Music : Jonny Lee Hart | Editor : Steve Smith | Producer : Zed Axis Productions

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