Make images greyscale
See also
Stimulus manipulation functions
align(),
crop_tem(),
crop(),
horiz_eyes(),
image_func(),
mask_oval(),
mask(),
mirror(),
pad(),
resize(),
rotate(),
to_size()
Stimulus manipulation functions
align(),
crop_tem(),
crop(),
horiz_eyes(),
image_func(),
mask_oval(),
mask(),
mirror(),
pad(),
resize(),
rotate(),
to_size()

