With Filestar you get 202 different skills for working productively with Group 4 FAX .(g4) files.
Group 4 FAX
Computer Fax Systems (CFS)
Group 4 (G4) used for black and white lossless compression to maintain high-quality images, commonly used in TIFF format compression by fax machines. A picture is seen as black dots and lines on a blank page; the fewer the dots and lines are, the lesser the file size.