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.