Apply the effect to an image specified as a PixMap.
Effects normally involve wholesale changes and so it may well be
necessary to change the color space and depth in order to apply the
effect. If the AutoRestore property is set
then the PixMap will be restored to a similar color space after
processing and it will be recompressed at an appropriate quality.
This default is generally what is required.
If the AutoRestore property is not set then the final output may
well have different characteristics such as color space and depth.
In general the final image will be uncompressed eight bit RGB no
matter what type of PixMap was supplied.
If you are relying on particular characteristics present in the
original PixMap then you should set the AutoRestore property to
false and then convert or recolor it after the effect has been
applied. Since the final image will be left uncompressed you will
likely want to recompress it using an appropriate schema.