Automatic vergence and focus control of a microstereoscopic camera

This work introduces a microstereoscopic camera that employs two microvideo sensors and a micromotion stage for automatic vergence and focus control. The parallel-axis stereo configuration using two video sensors enables the stereo camera to converge and focus simultaneously on a real object. To calibrate both vergence and focus with respect to object distance, we derive a nonlinear equation relating image disparity to object distance. Distance measurement using the equation yields very accurate results at near distances. To verify focus control, image focus of different object distances with and without automatic focusing is measured and compared. 3-D reconstruction results of real objects are also presented.