Convert tn3 to pnm Online: tn32pnm
You can use Tom's Editor to easily convert images from
Tiny Stuff .TN3 to Portable aNy Map .PNM.
Tom's Editor is a free, online image manipulation and converter program.
Go to Tom's Editor
Tiny Stuff is an image format with extension TN3.
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.