I have written quite a few automatic depth map generators. I do not think that in all cases is better than everyone else. It all depends on the stereo pair you start with. I personally think that a depth map generator based on a local method (based on a window or block) with smoother edge preservation is probably the best universal depth map generator.
Anyway, on this page:
depth map software
you can find depth map generator software based on optical flow based on weight windows, graphs and many other things that are related to creating a depth map and creating a lenticular shape. The best part is that all this is free.
To convert 2d-3d (which is more than what you are asking for), there is a piece of software called DMAG4 that uses a sparsely populated depth map (usually made in Gimp with a brush) to indicate the main depths and then fill in the blank areas. using interpolation, keeping edges of objects (keeping edges).
DMAG4 can be found here (it's free to use):
Software to convert 2d to 3d DMAG4
Another way to convert 2d to 3d is to use a program like Gimpel3d or Blender as a free one. Clearly, this is beyond the scope of the depth map, since you are essentially creating a 3D scene in which you can move around (using camera movement in Blender). This is often called "camera mapping."