This is the display format associated with the broadcast of slow-scan television. This legacy format was used to transmit a static image given limited bandwidth through the use of specialized software.
The G3 format is used to compress image files in TIFF format when sending faxes. The compression algorithm allows for the use of a standard 10-times compression, which can be increased. It is used to remove excess image data, which makes it possible to reduce the size of the image and speed up delivery.