I've created a hillshade raster (ArcGIS 9.3) and I have 16-Bit tiff image (please see attached). I need to submit 1 band/8-Bit with grey level (0-255) and set NoData for all pixels outside of the survey limit. My problem is while I'm changing to 8-bits, my NoData pixel changes to 0 value, which is wrong. How can I change this correctly and don't change NoData to 0?
For simple operation I can also use ArcGIS 10, I don't have any extensions for this version.