Each color channel is changed by
its own expression. The input values H,S and V
are based on the texture's old pixels. X and Y
reflect the pixels' coordinates, ranging from 0 to 1.
Image 4 for instance was created by setting H=Y,
which means that the vertical coordinates are translated to the
hue of the new colors. The saturation S was set to 1
for the entire texture (S=1). The brightness remained
unchanged (V=V or an empty field for V).