Convert pcs to pnm Online: pcs2pnm
You can use Tom's Editor to easily convert images from
PhotoChrome .PCS to Portable aNy Map .PNM.
Tom's Editor is a free, online image manipulation and converter program.
Go to Tom's Editor
PCS
PhotoChrome is an image format with extension PCS.
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.