Sensor-Based Auto-Focusing System

Robust extraction of features in a severely defocused image is the fundamental problem of a phase-difference autofocusing system. In order to solve this problem a multi-resolution feature extraction algorithm is proposed. Given the extracted features the proposed auto-focusing system can provide the ideal focusing position using phase correlation matching. Since the proposed system accurately estimates the phase difference in the out-of-focus blurred image under low illumination it can provide fast robust auto focusing.