Convert bm to pnm Online: bm2pnm

You can use Tom's Editor to easily convert images from
VBM/VDC BitMap .BM to Portable aNy Map .PNM.
Tom's Editor is a free, online image manipulation and converter program.

Go to Tom's Editor

BM

VBM/VDC BitMap is an image format with extension BM.

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.