Term:Animated GIF

An animated GIF is file format that contains a sequence of individual images in a single GIF file that are intended to be displayed in sequence over time. The result is that an animated GIF can be used to contain short videos and animations.

Animated GIFs are often used in place of traditional video file formats when the animation is short and sound is not required, as GIFs have no sound capability.

The video sequence is often played automatically by most GIF-displaying software, which can also be instructed to loop the video a specified number of times, or infinitely.

See also: GIF.

Animated GIF (Wikipedia)

GIF
Rotating earth (large).gif
Filename extension
.gif
Internet media type
image/gif
Type codeGIFf
Uniform Type Identifier (UTI)com.compuserve.gif
Magic numberGIF87a/GIF89a
Developed byCompuServe
Initial release15 June 1987; 34 years ago (1987-06-15)
Latest release
89a
(1989; 32 years ago (1989))
Type of formatlossless bitmap image format
Websitewww.w3.org/Graphics/GIF/spec-gif89a.txt

The Graphics Interchange Format (GIF; /ɡɪf/ GHIF or /ɪf/ JIF) is a bitmap image format that was developed by a team at the online services provider CompuServe led by American computer scientist Steve Wilhite and released on 15 June 1987. It has since come into widespread usage on the World Wide Web due to its wide support and portability between applications and operating systems.

The format supports up to 8 bits per pixel for each image, allowing a single image to reference its own palette of up to 256 different colors chosen from the 24-bit RGB color space. It also supports animations and allows a separate palette of up to 256 colors for each frame. These palette limitations make GIF less suitable for reproducing color photographs and other images with color gradients, but well-suited for simpler images such as graphics or logos with solid areas of color.

GIF images are compressed using the Lempel–Ziv–Welch (LZW) lossless data compression technique to reduce the file size without degrading the visual quality. This compression technique was patented in 1985. Controversy over the licensing agreement between the software patent holder, Unisys, and CompuServe in 1994 spurred the development of the Portable Network Graphics (PNG) standard. By 2004 all the relevant patents had expired.

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