image is the Torch7 distribution package for processing images. It contains a wide variety of functions divided into the following categories:

• Saving and loading images as JPEG, PNG, PPM and PGM;
• Simple transformations like translation, scaling and rotation;
• Parameterized transformations like convolutions and warping;
• Simple Drawing Routines like drawing text or a rectangle on an image;
• Graphical user interfaces like display and window;
• Color Space Conversions from and to RGB, YUV, Lab, and HSL;
• Tensor Constructors for creating Lenna, Fabio and Gaussian and Laplacian kernels;

Note that unless speficied otherwise, this package deals with images of size nChannel x height x width.

The easiest way to install this package it by following the intructions to install Torch7, which includes image. Otherwise, to update or manually re-install it:

$ luarocks install image

You can test your install with:

$ luajit -limage -e "image.test()"

> require 'image'
> l = image.lena()
> image.display(l)
> f = image.fabio()
> image.display(f)