Allows you to configure settings for saving a PNM (Portable aNy Map) image.
PNM isn't actually a format in itself, but encompasses PBM (Portable BitMap) for monochrome images, PGM (Portable Grayscale Map) for grayscale images and PPM (Portable PixMap) for color images.
The only configurable parameter for PNM images is the way that data is formatted either in ASCII (American Standard Code for Information Interchange) or raw (plain bytes). The raw format will produce significantly smaller filesizes and is faster to read and write.