pnmtoddif
Convert a PNM image to a DDIF image file. More information: https://netpbm.sourceforge.net/doc/pnmtoddif.html.
- Convert a PNM image to a DDIF image file:
pnmtoddif {{path/to/image.pnm}} > {{path/to/image.ddif}}
- Explicitly specify the horizontal and vertical resolution of the output image:
pnmtoddif -resolution {{horizontal_dpi}} {{vertical_dpi}} {{path/to/image.pnm}} > {{path/to/image.ddif}}