This is a ripoff of futcam, probably with more bugs, but with filters written in APL!
A filter consists of an APL program that is applied to every frame. When the program starts, the following variables will be defined:
image, which is an array of rank three with dimensions height,
width, and 3, where height and width are the dimensions of
the image and the three inner values are values for the different
color channels.
h, which contains the height of the image.
w, which contains the width of the image.
degree, which is a floating-point scalar. This values indicates
how much the filter should be applied, for instance, how a
brightness filter should change the intensity. This parameter can
be changed at runtime by the user using the arrow keys.
To make a change, a filter should set the image variable to a new
value. The value of image at the end of the program constitutes the
new color data. The size and rank of image should not be changed.
Changes to degree have no effect.
To add a filter, put it in an .apl file. The Makefile should
automatically pick it up. The name of the filter must not be a
Futhark keyword.