Convert pj to pnm Online: pj2pnm
You can use Tom's Editor to easily convert images from
HP PaintJet file .PJ to Portable aNy Map .PNM.
Tom's Editor is a free, online image manipulation and converter program.
Go to Tom's Editor
HP PaintJet file is an image format with extension PJ.
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.