pamscale

Scale a Netpbm image. More information: https://netpbm.sourceforge.net/doc/pamscale.html.

• 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