Convert ptif to pnm Online: ptif2pnm
You can use Tom's Editor to easily convert images from
Pyramid encoded TIFF .PTIF to Portable aNy Map .PNM.
Tom's Editor is a free, online image manipulation and converter program.
Go to Tom's Editor
PTIF
Pyramid encoded TIFF is an image format with extension PTIF.
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.