Associate a clip mask image with the current image.
The clip mask image must have the same dimensions as the current
image or an exception is thrown. Clipping occurs wherever pixels are
transparent in the clip mask image. Clipping Pass an invalid image
to unset an existing clip mask.
Associate a clip mask image with the current image. The clip mask image must have the same dimensions as the current image or an exception is thrown. Clipping occurs wherever pixels are transparent in the clip mask image. Clipping Pass an invalid image to unset an existing clip mask.