I  use a lot of apps, so I don't believe in being a "purist" in any particular 3d software. Whatever is the easiest tool to use for a task. In Bryce (I still use it) it would be dead-simple to import your B&W pic into the terrain lab, apply it as a heightmap in the picture section, drag the clipping-plane tool upward to clip off any black parts, and then export the terrain as an object. I have done this for logos quite a few times for use in other 3D apps, including Poser.  Bryce5 is still a free D/L if you don't have it. I still find it useful for shaping terrains and making greyscale animations to import into Carrara. Good luck,  Dan