Convert sgi to pnm Online: sgi2pnm
You can use Tom's Editor to easily convert images from
Silicon Graphics RGB .SGI to Portable aNy Map .PNM.
Tom's Editor is a free, online image manipulation and converter program.
Go to Tom's Editor
Silicon Graphics RGB is an image format with extension SGI.
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.