Creating depth map from a 2-D image?
No, it's not. The way many of the 3D sensors work is by projecting an infrared pattern onto the surface and measuring how it distorts. But with a 2D image, the pattern will simply be projected onto the flat 2D image, not onto the objects in the scene. So the 3D sensor will only sense a flat card.

Other methods work by combining 2 images taken with different cameras at different angles. This will have the same result as above. The 2D photo will be interpreted as a 2D surface by the combination of the 2 cameras.