Convert gfb to pnm Online: gfb2pnm
You can use Tom's Editor to easily convert images from
.GFB to Portable aNy Map .PNM.
Tom's Editor is a free, online image manipulation and converter program.
Go to Tom's Editor
is an image format with extension GFB.
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.