Questions about the JPEG file format. JPEG is a commonly used method of lossy compression for digital photography.

In digital images, JPEG is a commonly used lossy compression image file format, usually seen with the .jpg or .jpeg extensions. JPEG takes its name from its creator - the Joint Photographic Expert Group.

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, and is the file type most often produced in digital photography.

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. These format variations are often not distinguished, and are simply called JPEG.

The MIME media type for JPEG is image/jpeg (defined in RFC 1341), except in Internet Explorer, which provides a MIME type of image/pjpeg when uploading JPEG images.

JPEG supports a maximum image size of 65535×65535.

history | excerpt history