The Photo JPEG codec implements the Joint Photographic Experts Group (JPEG ISO version 9R9) algorithm for image compression.It is generally used for storage of still images. It can also be used for editing and storage of high-quality video files.
There are three JPEG-based codecs built into QuickTime. They are Photo JPEG, MJPEG-A, and MJPEG-B. MJPEG stands for 'Motion JPEG', and is indentical to Photo-JPEG except that the MJPEG codecs have translators built-in to support the different capture cards. We will only discuss the Photo-JPEG codec here; MJPEG-A and MJPEG-B have their own section.