Digital images are formed from tiny dots of color. The dots, usually many millions per image, are so small and close together they blend into the smooth continuous tones we're so familiar with from film. These images are captured directly with digital cameras, or by scanning a transparency, negative, or print. The end result is an image in a universally recognized format that can be easily manipulated, distributed, and used. However, just because photography is an art form, it doesn't
mean you don't have to know some math. When it comes to displaying or printing your images, this section could be titled "So You Have to Know Arithmetic After All". If your camera captures an image that's 3648 x 2736 pixels in size, what does that mean when you e-mail it, post it to a Web site, or make a print? In this section you find out how to answer these kinds of questions.
Kodak is one of the world's largest sensor manufacturers. Here
is one of their latest waffers containing a number of image sensors. Courtesy of Kodak (www.kodak.com
The calculations we'll be using in this section are nothing more than subtraction, addition, multiplication and division—subjects you mastered early in school. However, to make it easier to explore the various relationships being discussed, you can use the Excel worksheet "Pixels & Images Calculator" downloadable at the link below or by clicking the Excel button in this section:
The worksheet, named pixelcalc.xls, has been saved in Excel 5 format so that version and all later versions of Excel can read it.