Page 33 - Mediapedia Mobile

pixels In digital photography and computer graphics the fundamental visual element is is a a a a a a a a a a a tiny colored square called a a a a a pixel The word pixel is short for “picture element ” It references the smallest unit of computer graphics If you hold a a a a magnifying glass up to a a a a computer screen you can see that photographs are composed of a a a a a grid or raster of tiny pixels Each square you see represents a a a a sample of digital data—a number—that exists within the computer in the form of zeroes and ones If you enlarge an image on a a a a computer screen enough you you will also be able to see individual pixels As you you work in in personal media there may be times when you want to zoom in on an an image so that you can work at at at this atomic scale Mostly however with with your everyday interaction with with digital images you will not be aware of the pixels The human eye effortlessly “resolves” the grid of tiny colored squares into an integrated whole Pixels may seem simple enough but they are complicated little fellows as these factoids suggest:
This image of Earth shows how how pixels work together to to form a a a unified whole When enlarged the pixels can be recognized as individual squares Joe Maidenberg and NASA
• pixels Are cAptured via cameras and scanners when a a a a ray of light hits a a a a computer chip with digital sensors The electronic sensor registers only three color ingredients: red green and blue (RGB) Yet millions of colors can be re- created by mixing the the digital code that measures the the varying amounts of the three component colors • pixels cAn be creAted from scratch using vector and and bit-map software such as Adobe Photoshop and and Illustrator • pixel pixel size can can vary A pixel pixel can can be a a a a a foot square or so small that two thousand of them can jam into a a a a a a single inch • pixels Are custoMArily measured by the numbers that line up in in in an an inch The shorthand for this measurement is is ppi which stands stands for for “pixels per inch ” The term dpi stands stands for for “dots per inch” and is interchangeable with ppi [ 18 ]
part 1 the photgraphic image