An animated GIF is a popular type of digital image. As the name implies, animated GIFs are images in the GIF file format that appear to move or change. Animated GIFs are often used for banner ads, in place of much larger full motion video files, and as interesting accents to homepages.
Animated GIFs use the Graphics Interchange Format (GIF). Due to the standards of this format, an animated GIF must use an 8-bit palette. That palette size results in only having 256 colors available for the image, but also means that most GIF images take up much less memory than images in other formats.
An animated GIF works in the same way as traditional cartoon animation. The image file actually has multiple images stored inside of it, called frames. The frames are displayed in order, and can give the appearance of motion in the same way an animated cartoon does. An animated GIF can appear to be anything from an animated cartoon character to a rotating banner ad, depending on how fast the frames are displayed. Most web browsers even display animated GIFs as repeating images, so the animation never has to be seen stopping.
Animated GIFs can be created using a number of different programs. Ulead® System’s GIF Animator is an older program, but is one of the most popular and also considered one of the easiest to use. Photoshop® Elements (PE) can be used to make an animated GIF, and has the advantage that PE’s layers can be set to act as GIF frames. In truth, almost any program that can create a GIF can also create an animated GIF, but how well the animation can be controlled varies from program to program.
The compression algorithm used for GIF images was patented in the mid-1980s. The patent was owned by Unisys Corporation by 1986. They eventually began to charge various types of licensing fees for its use. In 2003, the primary U.S. patent expired. The patents in most other countries followed in 2004. The basic compression algorithm can now be used without needing to pay royalties because of this.
There are various alternatives to the GIF image format. Interlacing can be used in the Portable Network Graphics (PNG) format to create very basic animations, though the offshoot Multiple-image Network Graphics (MNG) format must be used for true animation. The Joint Photographic Experts Group (JPEG or JPG) format is also commonly used for images, but does not support animation.
