Convert dgc to pnm Online: dgc2pnm
You can use Tom's Editor to easily convert images from
DuneGraph (compressed) .DGC to Portable aNy Map .PNM.
Tom's Editor is a free, online image manipulation and converter program.
Go to Tom's Editor
DuneGraph (compressed) is an image format with extension DGC.
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.