Convert gfb to pnm Online: gfb2pnm

You can use Tom's Editor to easily convert images from
Atari GFB .GFB to Portable aNy Map .PNM.
Tom's Editor is a free, online image manipulation and converter program.

Go to Tom's Editor

GFB

Atari GFB is an image format with extension GFB.

PNM

PNM images are uncompressed 24 bit RGB images. Can cannot store Alpha channel. PNM images come in 2 types: binary and text. Especially popular on Linux.