ตัวแปลงไฟล์ออนไลน์ฟรี G4 เป็น RB

G4 is a method to compress black and white images without losing quality. It is used for fax machines and as a one of the compression types for the TIFF format. G4 treats a picture as black dots and lines on a white page (less file size will be achieved if there are less black dots and lines).

Was developed for the first mass-produced e-book reader – Rocket eBook. The format is written in Ruby. RB files are containers holding the entire content for a Rocket eBook device. It has DRM protection capability which is not used in the books published at present due to the format’s lack of popularity.