Vergence control of a parallel-axis stereo camera using signal processing

The vergence control method is presented for a parallel-axls stereo camera (PASC) using a signal processing technique such as shift, (rotation), and scaling. The PASC is considered as the simplest one of binocular stereo cameras. However, its major limitation lies in the controllability of vergence since its left and right imaging sensors of CCDs are fixed. On the other hand, a horizontal-moving-axis stereo camera (HMASC) with movable imaging sensors is able to control the vergence by moving its CCDs horizontally. In spite of its vergence controllability, there is a major drawback in the implementation because of complicated mechanical structure and the additional cost. To overcome the vergence control problem of the PASC, an operational principle of the HMASC is applied to the PASC. To be specific, without any additional hardware the vergence control problem of the PASC is solved with the signal processing technique. Assuming the virtual displacement between CCD`s, a disappearing part of acquired images is removed and the original image site is recovered via interpolation. Experimental results show that the vergence control between stereo images captured by the PASC it possible with an acceptable degradation of the image quality defending on the virtual displacement of CCDs.