Pixels, Resolution and File Types Using Digital Media in the Classroom START

What is a Pixel Two graphic types: Raster or Vector We will only be working with Raster images Raster or bitmap images are made up of pixelsbitmap –A pixel can be thought of as a dot of colorpixel The smallest part of an image that can be displayed Picture size of 640X480 –640 pixels wide by 480 pixels deep –307,200 pixels make up the picture Pixel Example

Screen Resolution Monitor screens display pixels Depending on the size of the monitor they will display between 72 and 96 pixels per inch Most common resolution 800 pixels X 600 pixels Can view at most a picture that is 800 pixels wide by 600 pixels deep Anything larger will have to be cut down to be viewed on the screen

Printing Resolution Printers print pixels Rule of thumb for printing digital images on a color inkjet printerprinting digital images –Divide the number of pixels in each dimension of the image by 300 and you will get the largest image size you should print successfully 800/300 X 600/300=2.67” X 2.0” print size But my printer can print 600dpi

File Size The more pixels in an image the larger the file sizefile size Large files take a long time to download if you put them on web pages or send them in an web pages Some companies limit the size of files you can put in an attachment A PowerPoint presentation using images that have a large file size will take a longer time to load and won’t look better on the screenPowerPoint presentation A printed picture will look better with more pixels and a large file size

Image Types Pictures can be different file typesfile types –You can tell by their file extensionfile extension Most common file types for images –.jpgjpg –.gifgif –.bmp or.wmf - ClipArt.bmp or.wmf

Take the Quiz Now that you have learned something about Pixels, Resolution, File Size and File Types it is time to take the Quiz in Oncourse. If you have difficulty with the quiz repeat this PowerPoint presentation and take it again. END SHOW

.jpg Internet Best for photographs Millions of colors Allows for a greater degree of compression compression –Therefore a smaller file size At a reduced quality –You can choose how much compression

.gif Internet Best for images with flat areas of color 256 colors Background can be made transparent Can be animated Read More

.bmp or.wmf Screen viewing in Windows Clipart in presentation software such as PowerPoint Cannot be used on the Internet