usage: grating width spatial_period phase orientation filename.bw
grating fills a square image of the given width with a sine-wave grating. The grating has the given spatial period (in pixels), phase (in degrees from mean grey at the centre of the image), and orientation (in degrees from vertical). All numeric parameters are floating-point numbers.
A grating can be multiplied with a mask using multimg. The program gabor is useful for creating such masks.
Author: Matthew Belmonte