Convert gun to pnm Online: gun2pnm
You can use Tom's Editor to easily convert images from
Gunpaint .GUN to Portable aNy Map .PNM.
Tom's Editor is a free, online image manipulation and converter program.
Go to Tom's Editor
Gunpaint is an image format with extension GUN.
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.