JNG (JPEG Network Graphics) is a sub-format of the MNG (Multiple-image
Network Graphics) format. As with MNG it extends on the features of the
popular PNG (Portable Network Graphics) image-format.
This sub-format was designed to support a lossy compression-method.
It is based completely on the JPEG specification. It adds the high-compression
ratios of JPEG for photographic images.
As a member of the Network Graphics family, JNG was deemed adequate as a
stand-alone format as it extends the JPEG format with color-correction and
transparency features.