Research on auto-focusing technology for micro vision system

The paper presents a passive auto-focusing technology by combining the discrete cosine transform(DCT) algorithm and small univalve segment assimilating nucleus(SUSAN) algorithm with evaluation function. The new method has the advantage of unimodal, local extremum and sensitivity of the focus curve. For the focusing search algorithm, the improved mountain climbing method which combined the large step and small step has been proposed, it makes the micro-vision system could find the focal plane more quickly and accurately.