pamflip

Flip or rotate a PAM or PNM image. More information: https://netpbm.sourceforge.net/doc/pamflip.html.

pamflip -rotate90|180|270 path/to/input.pam > path/to/output.pam

pamflip -leftright path/to/input.pam > path/to/output.pam

pamflip -topbottom path/to/input.pam > path/to/output.pam

pamflip -transpose path/to/input.pam > path/to/output.pam