When a digital photograph or piece of graphic art on a computer screen is magnified many times, you can see that it is made up of many small squares. These small squares are called pixels, a short name for picture elements. Thousands of pixels together show us an image the same way that putting a jigsaw puzzle together shows us a picture.To determine if an image will fit on a specific size computer screen, multimedia specialists need to know two things: the screen's resolution and the screen's pixels per inch (PPI).
Resolution: The number of pixels on a computer screen is called the resolution.
If a screen displays 800 pixels across and 600 pixels up and down, the resolution is 800 pixels wide by 600 pixels high or800 x 600
Pixels Per Inch: PPI measures how many pixels are in a square inch of an image on a computer screen. Multimedia specialists use the following formula to determine the PPI of a computer screen.
If the screen resolution is 800 X 600 pixels and the computer screen is 12.5 inches wide, the PPI is 64. 800 / 12.5 = 64 Pixels wide / Inches wide = PPI
Calculate the PPI of the computer screens indicated below. Round pixels-wide to a whole number.