Convert htm to pnm Online: htm2pnm

You can use Tom's Editor to easily convert images from
HTML Table Image .HTM to Portable aNy Map .PNM.
Tom's Editor is a free, online image manipulation and converter program.

Go to Tom's Editor

HTM

This is a very simple format where every pixel is saved as a cell in HTML table. You can view such files in every web browser, for eg. Firefox or Chrome.

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.