The GP4 file extension is related to the CCITT Group 4 image file format used by the Comité Consultatif International Téléphonique et Télégraphique.
There are 2 other file types using
the GP4 file extension!
.gp4 - Guitar Pro 4 project [common]
.gp4 - GTX Group IV format CALS picture
GP4 file extension - CCITT Group 4 image file
What is gp4 file? How to open gp4 files?
File type specification:
The GP4 file extension is also used for some sort of image file used by Comité Consultatif International Téléphonique et Télégraphique, an organization that sets international communications standards. CCITT, now known as ITU (the parent organization) has defined many important standards for data communications.
A protocol for sending fax documents over ISDN networks, the Group 400 protocol supports images of up to 400 dpi resolution.