Progressive JPEG (.pjpeg)
The PJPEG (Progressive JPEG) is a file extension for images that enhances the standard JPEG format by displaying images in successive waves of increasing detail, improving the user experience during slow network conditions. The JPEG stands for "Joint Photographic Experts Group", the organization that developed the standard in 1992. PJPEG is particularly useful for web applications, as it allows images to appear more quickly and progressively refine in quality, rather than loading from top to bottom like baseline JPEGs.