Simple Graphics Tutorial

This is a brief simplistic explanation of some of the types of free graphics that are available at this site. There are two major types of animation formats - animated gifs and avis. Both are useful for animations on web pages. Animations are a series of pictures (frames) which are sequential displayed as a movie would be displayed on your VCR. Animated gifs and avis are different formats for these picture sequences. Other popular formats include .mov (Apple computer - Quicktime) and .mpg (mpeg). All of these different formats have advantages and disadvantages. No one format has dominated the industry yet.

Gif animation is quite popular and is supported by Netscape as well as Internet Explorer. It has built-in compression and supports transparent backgrounds so it can blend in better with different colored backgrounds. It's disadvantages include limitation to 256 colors (not close to photo-realistic) and only can be viewed within a browser as it is not a real movie format. There is no audio component. The software to create such animations is mostly shareware, quite simple to operate, and very good. The display by the different browsers is not perfect. IE 3.0 doesn't support variable frame wait states and runs all the frames at maximum speed. Netscape doesn't support replacing any image with anything but background. IE 3.0 will let you replace an image with a previous image. An example of this can be seen here. It is the ball rotating around the barber poles. You have to view it with both Netscape and IE 3.0 to see the differences.

AVIs are a true movie format developed by Microsoft. It supports true color (millions) and audio. There are various compression formats available, some of which are quite good. Netscape and IE both support the format. Drawbacks are the file size is usually larger than Gifs but the picture quality is better. Transparency is not supported (except for new indeo interactive) which is a true drawback on web pages. Also one must have a copy of the various compressors to view the movie. The compressors are free and widely distributed but Indeo Interactive is still fairly new and some of our newer avis use that compressor. Avis are standard with PCs but not standard across all platforms.

All of these animations may be displayed on a web page at different resolutions or sizes. At Media Link the animation is displayed at the size it was created. However, these may be displayed at stretched or shrunken sizes to fit within web pages as the user desires. For example, a horizontal bar created at 500 x 20 could be placed on a web page at 800 x 20 or 800 x 30 to fill the entire width of a page. It may look distorted if the dimensions are asymmetrically changed but the animation would animate correctly. There are some peculiarities for Netscape and Internet Explorer users which can be seen here.

If there is interest, I will discuss on this page the other formats as well as some of the tools used to create some of our animations.