A simple command-line image manipulation program. Supports reading and writing GIF, JPEG, and PNG files.
Installing via go:
go get -u github.com/jangler/imp
If you use Arch Linux or a derivative, you may also install via the AUR package.
Usage:
imp <infile> [-q <n>] [<outfile>] [<filter> ...]
imp help [<filter>]
imp version
Applies filters to the image 'infile' and writes the result to 'outfile'.
If 'outfile' is not given, 'infile' is overwritten.
The -q option, if given, controls JPEG quality (1-100). The default is 100.
Filters are applied in the given order and may be invoked multiple times.
Filters:
blur <radius> <power>
crop <x> <y> <w> <h>
impose <layer> <file> [<x> <y>]
join <file> <edge> [<align>]
lum <factor> [<gFactor> <bFactor> [<aFactor>]]
mask <file>
palette <file>
rotate <degrees>
sat <factor>
scale <w> <h>
Convert a PNG to a low-quality JPEG:
imp image.png -q 30 image.jpg
Crop an image to its top-right quarter, in-place:
imp image.png crop 50% 0 50% 50%
Scale an image to a 16x16 icon, rotate it 90° clockwise, and tint it dark red:
imp image.png icon.png scale 16 16 rotate 90 lum 0.75 0.25 0.25
Join several images together:
imp ne.png result.png join nw.png right join s.png bottom