Before the early 1990s, the Internet was primarily a text-based medium as bitmap (binary data) images were too large to easily download or distribute. This all changed with the introduction in 1992 of the JPEG—a new standard for compressing the size of images.
These days the term JPEG is well known, but surprisingly it was not meant to be the name of a picture format. The term comes from the Joint Photographic Experts Group, the international organization set up in 1986 that came up with the standard compression algorithm responsible for reducing the amount of memory JPEG pictures take up. Technically, the JPEG format is called JFIF, for JPEG Pile Interchange Format, but the name never stuck.
JPEG works by converting the pixels of a color image into blocks of pixels, and then taking an average of the values of the brightness and color of these blocks so that less data needs to be saved. Further compression is done by quantization (a mechanism that removes high-frequency noise) and a complicated process called Discrete Cosine Transformation, The compression is done intelligently, so, depending on the level of compression, the loss of detail is not obvious to the human eye. Despite the fact that each time an image is resaved more data is thrown away and the quality is reduced, this has not prevented its ubiquitous use on the Internet.
The JPEG organization has also come up with a new format called the JPEG 2000, a new improved lossless form of the JPEG. It will have to do well to replace the original, which, due to its widespread adoption on the Web and on digital cameras, is likely to be the image format of choice in standardized digital archives, meaning its future is assured.
