Three Dimensional Measurement by Epipolar Plane Image Analysis
The epipolar-image analysis is used for grasping of an object by the manipulator robot. The time-sequence images are captured by the CCD camera fixed on the hand of the manipulator. The CCD camera is moved straight by the small steps, and the image is captured at each position. The motion trajectories of the objects are appeared on the epipolar-image as follows.

CCD camera on the hand of the manipulator.
Scene (target indicator was superimposed).


Image stream with occlusion
(vertical direction).
Edge detection result.
(one dimensional simple edge operator).

Image stream with occlusion
(horizontal direction).
Edge detection result.
(one dimensional simple edge operator).

The slant of the motion trajectory varies inversely as the depth of the object. That is, the three dimensional information are represented by the slant of the motion trajectory. Thus the three dimensional position of the object can be calculated by extracting the its motion trajectory. The extraction of the motion trajectory corresponds to the matching in the binocular stereo. An experimental result of the object grasping is shown below.


Image stream.
Object grasping based on vision.