(0:00) In this video clip we will compare the two dominant image types used on web pages. These file formats are GIFs and JPEGs. It's important to choose the right file format for the right job.

(0:17) In general, GIFs are used when the image requires few colors (GIFs are capable of dislaying a maximum of 256 colors). For instance, the Georgia Southern logo uses three colors; navy, gold, and white. This image saved as a GIF with only three colors will be a very small file (4 kilobytes). However, limiting colors in this manner can result in "jaggies" or an appearance of rough edges where lines are not straight. Let's zoom in here to see the eagle's eye up close. As you can now see -- it is a little jagged. But, as a gif this image look pretty good... and it is very small in file size (4k).

(1:16) If it was a JPEG would it look any better? Let's see. Here it is as a JPEG image. Let me flip back a forth between these a few times... and now let's have a split screen. The edges of the JPEG are a little smoother... but can you see are the "pixel garbage" in this image? Let's zoom in again. JPEGs are great for images where thousands of colors are required- like a closeup of a persons face. But in this case the eagle logo (as a jpeg) looks pretty bad. So as a rule of thumb, logos or simple cartoon type images should be saved as GIFs with as few colors as required.

(2:10) So then- why do we need JPEGs? Well, most digital cameras and image scanners save images as JPEGs. Why? Because JPEGs may contain thousands, even millions of colors-- and so images from nature CAN be displayed on a computer monitor. When realism is required JPEGs are often far superior to GIFs. Take a look at this image. This is a photo of Kent Rittschof-- saved as a JPEG- it's a bit large -- 66k. Let's compare it to Kent saved as a GIF. Woah! The GIF was saved using 216 colors and is only 14k. But what do you think of the quality? It's far inferior to the JPEG.

(3:08)Another place where it is important to use JPEGs is when you have and image of a landscape where the sky is visible. The sky has a gradual transition from light to darker shades of blue. A JPEG can display this, but a GIF will render the sky as bands of blue shades.

(3:30) There ARE other reasons for using GIFs! GIFs can have one color transparent. This is useful if you want an image to appear atop a web page background. Here is a GIF image of Gus. Gus is our mascot here at Georgia Southern. Note the lime green color surrounding him. Here is what this image looks like atop a webpage with the lime green color transparent. JPEGs cannot have a transparent area when placed on a web page.

(4:09) Another reason that GIFs are used is for animations. Here is a sample of how GIF animation might be used for instruction. JPEGs only have one layer and so are static images. GIFs however, can have many layers-- and these layers can be revealed in a desired sequence to create simulated movement.