pnmrotate — Rotate a PNM image. More information: <https://netpbm.sourceforge.net/doc/pnmrotate.html>.

Rotate a PNM image by some angle (measured in degrees, counter-clockwise)

pnmrotate {{angle}} {{path/to/input.pnm}} > {{path/to/output.pnm}}

Specify the background color exposed by rotating the input image

pnmrotate {{[-b|-background]}} {{color}} {{angle}} {{path/to/input.pnm}} > {{path/to/output.pnm}}

Disable anti-aliasing, improving performance but decreasing quality

pnmrotate {{[-n|-noantialias]}} {{angle}} {{path/to/input.pnm}} > {{path/to/output.pnm}}