Editing Rasters

Hi,

I have been told that within the software you can edit rasters i.e. I have a scanned drawing in a *.tif format. The image is very noisy due to the poor quality scan. I would like to remove / reduce the noise. Can this be done? If so how? Thanks. Unfortunately we don't have the original paper copy.

Large areas of the drawing should be white and it's not!

Microstation version  08.11.09.832

Thanks

Matt