Computes an arbitrary rectangular region of the RenderedImage
and copies it into a caller-supplied WritableRaster. The region
to be computed is determined from the bounds of the supplied
WritableRaster. The supplied WritableRaster must have a
SampleModel that is compatible with this image. If raster is null,
an appropriate WritableRaster is created.
Returns:
a reference to the supplied or created WritableRaster.
Parameters:
-
raster - a WritableRaster to hold the returned portion of the
image, or null.