Graphics Interchange Format
Graphics Interchange Format (often shortened to GIF) is a file format for images.[1]
.gif) A rotating globe in GIF format. Posterization is noticeable in the blue gradient areas due to the restricted palette. | |
| Filename extension | .gif |
|---|---|
| Internet media type | image/gif |
| Type code | GIF GIFf |
| Uniform Type Identifier (UTI) | com.compuserve.gif |
| Magic number | GIF87a/GIF89a |
| Developed by | CompuServe |
| Type of format | Raster graphics image format |
It is a raster graphics format; that is the image has a fixed size. CompuServe developed and introduced the format in 1987. Today, it is widely used on the World Wide Web.The format supports up to 8 bits per pixel, or 256 colors. It also supports animations. Each frame of an animation can have its own set of 256 colors.[2] GIF is not used to show photographs very much, because having only 256 colors is limiting for such a task.
To reduce their size, images are compressed using Lempel–Ziv–Welch compression. Lempel-Ziv-Welch, or LZW, is a lossless compression. No information is lost when compressing or uncompressing. There were some problems with the patent of the LZW compression. That patent was not held by CompuServe, but by Unisys. These issues led to the development of another format, called PNG. This is no longer a problem, because the patents have expired.
A GIF may often represent a small clip of a favorite scene from a show or video.
Pronunciation of GIF
The creators of the format pronounced the word as "jif" with a soft "G" /dʒɪf/ as in "gin". Steve Wilhite says that the intended pronunciation deliberately echoes the American peanut butter brand Jif, and CompuServe employees would often say "Choosy developers choose GIF", spoofing this brand's television commercials.[3]
The disagreement over the pronunciation led to heated Internet debate. On the occasion of receiving a lifetime achievement award at the 2013 Webby Award ceremony, Wilhite rejected the hard-"G" pronunciation, and his speech led to 17,000 posts on Twitter and 50 news articles.[4]
Graphics Interchange Format Media
A humorous image announcing the launch of a Tumblr account for the White House suggests pronouncing GIF with a hard g.
An example of a GIF image saved with a web-safe palette and dithered using the Floyd–Steinberg method. Due to the reduced number of colors in the image, there are display issues.
A small black and white sample image
Bytes Dh to 30Ch in the example define a palette of 256 colors.
Quilt design as 46x46 uncompressed GIF
GIF can be used to display animation, as in this image of Newton's cradle.
References
- ↑ "GIF" is pronounced with a hard G.
- ↑ "GIF (Graphics Interchange Format) Definition". techterms.com. Retrieved 2021-05-17.
- ↑ "The GIF Pronunciation Page". www.olsenhome.com. Retrieved 2019-03-04.
- ↑ (in en-GB) Gif inventor says pronounce it 'Jif'. 2013-05-22. https://www.bbc.com/news/technology-22620473. Retrieved 2019-03-04.