Example for the Whirl and Pinch filter
“Whirl and Pinch” distorts your image in a concentric way.
“Whirl and Pinch” distorts the image much like the little
whirlpool that appears when you empty your bath.
“Pinch” can be compared to applying your image to a soft
rubber surface and squeezing the edges or corners. If the Pinch amount
slider is set to a negative value, it will look as if someone
tried to push a round object up toward you from behind the
rubber skin. If the Pinch amount is set to a positive value, it
looks like someone is dragging or sucking on the surface from
behind, and away from you.
The “pinch” effect can sometimes be used to compensate
for image distortion produced by telephoto or fish-eye lenses