.PNM File

The pnm file extension is mainly associated with portable anymap format, which is a collective form of Netpbm formats.

PNM is a family of formats supporting portable bitmaps (PBM) , graymaps (PGM), and pixmaps (PPM).

MIME types:
application/x-portable-anymap
image/x-portable-anymap

Files with the pnm file extension can be typically found as graphics formats in any of the portable anymap bitmap graphic format.

How to open:

Use any graphic viewer/editor (XnView, Adobe Photoshop or similar) to open and edit *.pnm file.

How to convert:

Many graphics editors nowadays support PNM format and can resave it to other graphics formats.