Motion in Depth
As in other aspects of vision, the observer's visual input is generally insufficient to determine the true nature of stimulus sources, in this case their velocity in the real world. In monocular vision for example, the visual input will be a 2D projection of a 3D scene. The motion cues present in the 2D projection will by default be insufficient to reconstruct the motion present in the 3D scene. Put differently, many 3D scenes will be compatible with a single 2D projection. The problem of motion estimation generalizes to binocular vision when we consider occlusion or motion perception at relatively large distances, where binocular disparity is a poor cue to depth. This fundamental difficulty is referred to as the inverse problem.
Read more about this topic: Motion Perception
Famous quotes containing the words motion and/or depth:
“The motion picture is like a picture of a lady in a half- piece bathing suit. If she wore a few more clothes, you might be intrigued. If she wore no clothes at all, you might be shocked. But the way it is, you are occupied with noticing that her knees are too bony and that her toenails are too large. The modern film tries too hard to be real. Its techniques of illusion are so perfect that it requires no contribution from the audience but a mouthful of popcorn.”
—Raymond Chandler (1888–1959)
“Primarily I am a passionately religious man, and my novels must be written from the depth of my religious experience.”
—D.H. (David Herbert)