Digital Imaging is a process where an electronic photograph, scanned document, or image is converted into a series of electronic dots called pixels. Pixels is an acronym for "picture elements".
After the image is converted, or digitized, it is stored on a memory storage device which may be a hard drive or some sort of electronic storage device such as a memory stick. The pixels are stored in a compressed format to save storage space.
As each pixel is being created it is assigned a color value, called a tonal value, of black, white, shades of grey, or an actual color. These pixels must be processed by a piece of software in order for them to be called up and viewed as an actual image later.
Traditional cameras capture images onto film while digital cameras use an electronic chip known as a Charged Coupling Device (CCD). The CCD is actually a grid of miniature light-sensitive diodes. These diodes convert photons (light) that strikes them into electrons (electrical impulses). The technical name for these diodes is 'photosite'. The brighter the light is that hits the photosite the stronger the electrical charge is that's produced.
After converting the photons into electrons, a mini-computer, located inside of the camera, reads the stored electrical value in each photograph. Then a built-in analog-to-digital converter turns the stored electrical value into a digital value. These digital values are then stored on the cameras memory storage device. When these digital values are recalled by software, and displayed on a screen, they reproduce the image that was originally captured by the camera or digital input device.
The digital image that is created by the CCD is huge. It's far too big to be easily stored in the relatively little amount of storage space that's available to a digital camera. Accordingly, the camera's computer compresses the image to make it smaller.
There are two basic methods for achieving this compression. The first method takes advantage of repetitive patterns in the image. For example, if you are taking a picture of an airplane that is flying in the sky, a lot of the picture will be a chunk of blue sky. The camera recognizes that there are multiple parts of the image containing the same digital information, so it only records a small piece of the sky. Then it simply creates a map to tell it where the rest of the sky belongs. When the picture is ultimately displayed the sky appears exactly the same as it did in the original image when it was first captured. The only difference is that the overall storage requirements were reduced thanks to the camera's clever mapping techniques.
The other method uses a procedure called irrelevancy. This methodology automatically removes digital information that is not visible to the human eye such an infra red light.
Digital imaging is amazing yet we have only started witnessing the revolutionary changes that are yet to come.
Digital Imaging Explained
September 24, 2005
|
Warren Lynch has been shooting commercial photography since 1979. Clients include Several Regional and National accounts. Sign up for"The Digital Dose" and receive his tips every other week for FREE! http://www.photopheed.com.
contact@photopheed.com
Lastest Headlines for "Internet"
- American launches in-flight Internet on 3 routes (AP via Yahoo! News)
American Airlines expanded the availability of in-flight Internet access Wednesday, launching airborne e-mail, Web and other online services on some of its longer, nonstop flights. - American expands inflight Internet service (USA Today)
American Airlines said Tuesday it's expanding its inflight Internet service to the rest of its 767-200 fleet, or the 15 planes that fly primarily transcontinental flights. - Games attract record viewers and Internet a hit (Reuters via Yahoo! News)
The Beijing Olympics will become the most viewed Games in their 112-year history, boosted by a hugely popular Internet platform, the IOC said on Wednesday. - American Air kicks off in-flight Internet service (Reuters via Yahoo! News)
AMR Corp's American Airlines began offering Internet access on long-haul domestic flights on Wednesday, making American the first U.S. airline to offer full in-flight broadband. - American Airlines Launches Internet on 3 Routes (Fox News)
One of the few remaining Internet-free havens vanished Wednesday as American Airlines launched airborne e-mail, Web and other online services on some of its longer, nonstop flights. - Nokia to Cut 200 Jobs in Internet Services (PC Magazine)
The world's top cellphone maker Nokia Oyj said on Wednesday it was looking to cut 200 jobs at its new Internet services unit. - FCC chief proposes free Internet (UPI)
WASHINGTON, Aug. 20 (UPI) -- A U.S. government official says high-speed Internet access should be available to all residents even if that means providing it free of charge. - American launches in-flight Internet on 3 routes (San Francisco Chronicle)
One of the few remaining Internet-free havens vanished Wednesday as American Airlines launched airborne e-mail, Web and other online services on some of its longer, nonstop flights. The move could create a new stream of revenue for an aviation industry facing... - Why can't Firefox print as well as Internet Explorer? (CNET)
Printing seems to be at the bottom of Mozilla's priority list. It's time to make Firefox the equal of Internet Explorer in terms of printing Web pages. - Acquisition Helps Ready Internet Security Software Firm For Web 2.0 (Investor's Business Daily via Yahoo! News)
Most people know Websense as the forbidding white page that pops up when you try to visit a Web site your employer doesn't care for. But that business isn't enough in the ever more complex world of Internet security.