A new algorithm for the Deterrace plug-in is under development. When completed it should be both faster and more accurate.
Screenshot: http://www.daylongraphics.com/products/leveller/gallery/deterrace2.pngThe above sample (1000 pixels square) shows the preexisting contour lines, which are handy as a reference but technically should not be present.
Unlike the old algorithm, large terrain resolution and/or large plateaus do not leave flat unprocessed areas; every pixel gets fully evaulated.
Ray