This is an abstract base class that adds the ability to specify the
Color Space that the operation should take place in (linear sRGB or
gamma corrected sRBG).
This filter primitive lights an image using the alpha channel as a bump map.
The resulting image is an RGBA opaque image based on the light color
with alpha = 1.0 everywhere.
This is an extension of our Filter interface that adds support for
a color-interpolation specification which indicates what colorspace the
operation should take place in.