Can someone give me a definition of the term, "pixel?"

THANK YOU!

-- Martie Sample (MSample@bamaed.ua.edu), September 21, 1999

Answers

Pixel = 'Picture element'. There is no standard deeper definition.

It is the smallest dot that the camera, or printer, or computer knows about. It might be represented by a single bit (black/white), or 8 bits (shades of grey, or a few colours), 24 bits, 36 bits, or anything else really. More bits are better. One pixel of 24 bits has the same information as 3 each of 8 bits.

-- Alan Gibson (Alan.Gibson@technologist.com), September 21, 1999.

Just for S&G's, there is, I think, one smaller unit, sometimes referred to as the sub-pixel or pel. Each of the 3 or 4 bytes that actually form a full color pixel are pels. Keeping this information separated is necessary to preserving the amount of each of the three primary colors present in a pixel. Anybody else have a name for these thingamabobs?

-- Gerald Payne (gmp@francorp.francomm.com), September 21, 1999.

Martie,

A good source for this and other info about digicams is Dennis Durtin's digicams short courses that are on the web and can be printed out--free except for the cost of ink and paper. They are at: http://www.shortcourses.com/ .A second good source of web info is the Kodak courses found at: http://webs.kodak.com/US/en/digital/dlc/. Read those two tutorials and you will know more about digicams than most people.

To quote from Dennis Curtin concerning pixels, "Unlike traditional cameras that use film to store an image, digital cameras use a solid- state device called an image sensor. These fingernail-sized silicon chips contain hundreds of thousands or millions of photosensitive diodes called photosites. Each of these photosites records the intensity or brightness of the light that fall on it. Each photosite reacts to the light that fall on it by accumulating a charge; the mmre light, the higher the charge. The brightness recorded by each photosite is then stored as a set of numbers that can be used to set the color brightness of dots on the screen or ink on the printed page to reconstruct the image."

Dennis also explains how color is captured and just about everything else you might want to know about how digicams operate. Whatever Dennis doesn't cover can probabably be found at the Kodak site.

Rodger

-- Rodger Carter (rodger.carter@wpafb.af.mil), September 22, 1999.