>>15790688JPEG (/ˈdʒeJpɛɡ/ JAY-peg)[2] is a commonly used method of lossy compression for digital images, particularly for those images produced by digital photography. The degree of compression can be adjusted, allowing a selectable tradeoff between storage size and image quality. JPEG typically achieves 10:1 compression with little perceptible loss in image quality.[3] Since its introduction in 1992, JPEG has been the most widely used image compression standard in the world,[4][5] and the most widely used digital image format, with several billion JPEG images produced every day as of 2015.[6]
The term "JPEG" is an initialism/acronym for the Joint Photographic Experts Group, which created the standard in 1992. The basis for JPEG is the discrete cosine transform (DCT),[1] a lossy image compression technique that was first proposed by Nasir Ahmed in 1972.[7] JPEG was largely responsible for the proliferation of digital images and digital photos across the Internet, and later social media.[8]
JPEG compression is used in a number of image file formats. JPEG/Exif is the most common image format used by digital cameras and other photographic image capture devices; along with JPEG/JFIF, it is the most common format for storing and transmitting photographic images on the World Wide Web.[9] These format variations are often not distinguished, and are simply called JPEG.
The MIME media type for JPEG is image/jpeg, except in older Internet Explorer versions, which provides a MIME type of image/pjpeg when uploading JPEG images.[10] JPEG files usually have a filename extension of .jpg or .jpeg. JPEG/JFIF supports a maximum image size of 65,535×65,535 pixels,[11] hence up to 4 gigapixels for an aspect ratio of 1:1. In 2000, the JPEG group introduced a format intended to be a successor, JPEG 2000, but it was unable to replace the original JPEG as the dominant image standard.[12]