Digital Imaging Explained

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.

About The Author

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.

[email protected]

In The News:

2021 Ocean Photography Awards  Popular Photography Magazine
The Captive Photograph  Boston Review

Digital Image Files ? Megapixels, Megabytes, or DPI?

When I promised readers that I was going to do... Read More

Safari Wildlife Photography Top Four Tips

I've been practising wildlife photography on safari for over twenty... Read More

Photography Success Without School

What I learned from a mentor that enabled me to... Read More

Bracketing and How To Use Tt Correctly...

What Is... Exposure BracketingExposure bracketing is a simple technique professional... Read More

Canon-Powershot-A80 Review

Last month we bought the Canon Powershot A80 online for... Read More

Imperfect Photos And How You Can Fix Them

So your picture came out less then perfect. Blemishes or... Read More

The Paradigm: Going Digital

As you might imagine the paradigm shift from traditional film-based... Read More

The Primer on Digital Camera Printers

Once you have clicked photos through your digital camera, then... Read More

Picture Framing for Photographers - Part 2

There are two sources for obtaining the moulding for making... Read More

Kodak Digital Cameras - The Giant Comes To Digital

George Eastman, founder of Kodak is world renowned today. Digital... Read More

Light Meter Readings for Film and Digital

Reflected Light Readings for Film and Digital ImagesIn order to... Read More

Crooked Horizons in Your Photos? ? Here is a Five Minute Digital Fix

Remember the good old photography days?Film camera in hand, you... Read More

Review of the Photek Product Shooting Tent

Here's the challenge. You have to photograph small items for... Read More

Tips for Better Vacation Photos

Photos are a great way to share your travel experiences... Read More

Making Money With Digital Photography And Live Events

A few years ago I became interested in digital photography,... Read More

The Benefits of Disposable Cameras

Disposable cameras are cheap and easy to use. If you... Read More

The Best Wildlife Camera To Take On Safari

Good wildlife camera equipment on safari can make the difference... Read More

Selecting Good Stock Photography in the Age of Digital

The business of stock photography has drastically changed over the... Read More

Tiny Cameras, Big Pictures and Make Your Photos Great!

The path to picking a digital camera usually leads to... Read More

How To Make A Time-Lapse Video With Your Digital Video Camera

Getting the most out of your digital video camera can... Read More

Is Film Better than Digital for Weddings?

As a professional wedding photographer I get this question asked... Read More

HP Digital Cameras - History and Beyond

HP has started making digital cameras only recently. However, the... Read More

The Photography Portfolio: Building Your Reputation

If you have hopes of becoming a professional photographer, or... Read More

How to Create a Family History Video Memoir with Photos and Interviews of Your Loved Ones

Here are examples of two basic videos you can create... Read More

Help! My Old Colour Photo has Turned Pink ? 5 Minute Digital Fix

Almost all of us will have seen this particular photographic... Read More