The shadow x offset.
The shadow y offset.
The standard deviation of the Gaussian operator used to produce the shadow. The higher the number, the "blurrier" the shadow, but the longer it takes to produce the shadow.
The percent opacity of the shadow. A number between 0.1 and 1.0
The shadows for this image.
Simulates a shadow from the specified image and returns it. This method only works when the image has opaque parts and transparent parts. Note that the resulting image is just the shadow.