Convert tru to pnm Online: tru2pnm
You can use Tom's Editor to easily convert images from
IndyPaint .TRU to Portable aNy Map .PNM.
Tom's Editor is a free, online image manipulation and converter program.
Go to Tom's Editor
IndyPaint is an image format with extension TRU.
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.