pamscale
Scale a Netpbm image.
TLDR
Scale an image such that the result has the specified dimensions
$ pamscale -width [width] -height [height] [path/to/input.pam] > [path/to/output.pam]
Scale an image such that the result has the specified width, keeping the aspect ratio
$ pamscale -width [width] [path/to/input.pam] > [path/to/output.pam]
Scale an image such that its width and height is changed by the specified factors
$ pamscale -xscale [x_factor] -yscale [y_factor] [path/to/input.pam] > [path/to/output.pam]
Scale an image such that it fits into the specified bounding box while preserving its aspect ratio
$ pamscale -xyfit [bbox_width] [bbox_height] [path/to/input.pam] > [path/to/output.pam]
Scale an image such that it completely fills the specified box while preserving its aspect ratio
$ pamscale -xyfill [box_width] [box_height] [path/to/input.pam] > [path/to/output.pam]
