pnmflip
Flip and rotate PNM images
TLDR
Flip horizontally
$ pnmflip -lr [input.pnm] > [output.pnm]
Flip vertically$ pnmflip -tb [input.pnm] > [output.pnm]
Rotate 90 clockwise$ pnmflip -cw [input.pnm] > [output.pnm]
Rotate 90 counter-clockwise$ pnmflip -ccw [input.pnm] > [output.pnm]
Rotate 180$ pnmflip -r180 [input.pnm] > [output.pnm]
SYNOPSIS
pnmflip [options] [file]
DESCRIPTION
pnmflip flips and rotates PNM images. Part of Netpbm toolkit for image manipulation. Supports all basic geometric transformations.
PARAMETERS
-lr
Flip left-right.-tb
Flip top-bottom.-cw
Rotate 90 degrees clockwise.-ccw
Rotate 90 degrees counter-clockwise.-r180
Rotate 180 degrees.-transpose
Transpose rows and columns.
INSTALL
sudo apt install netpbm
sudo dnf install netpbm
sudo pacman -S netpbm
sudo apk add netpbm-extras
sudo zypper install netpbm
brew install netpbm
nix profile install nixpkgs#netpbm