|Uniform Type Identifier (UTI)||com.compuserve.gif|
GIF (Graphics Interchange Format) is a bitmap image format that was developed by US-based software writer Steve Wilhite while working at the internet service provider CompuServe in 1987 and has since come into widespread usage on the World Wide Web due to its wide support and portability.
The original GIF format, also known as "GIF 87a," was published by CompuServe in 1987. In 1989, CompuServe released an updated version of the format called "GIF 89a." The 89a format is similar to the 87a specification, but includes support for transparent backgrounds and image metadata. Both formats support animations by allowing a stream of images to be stored in a single file. However, the 89a format also includes support for animation delays.
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 the GIF format less suitable for reproducing color photographs and other images with continuous color, but it is 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.
How to pronounce "GIF"
According to Steve Wilhite, the creator of the original GIF format, it is pronounced "jiff" (like the peanut butter brand). However, most people still pronounce it "gif" (with a hard G). Therefore, either pronunciation is acceptable.