Here's an example:
Joint image. We want the previous image to be smoothed but we also want the smoothing to maintain the edges between the colored blocks.
Smoothed (filtered) image using spatial standard deviation = 60, range spatial deviation = 0.4, and number of iterations = 3. As can be seen, the noise was smoothed and the edges have been preserved, exactly what we wanted.
For an example that shows edge preserving smoothing applied to an actual depth map, you are invited to check 3D Photos - Hard at work.
The windows executable (guaranteed to be virus free) is available for free via the 3D Software Page.