【摘要】 聚焦评价函数和极点搜索策略是自动聚焦的重要模块,直接影响聚焦的效果。为同时满足自动聚焦速度和精度上的要求,提出了一种新的自动聚焦算法。该算法综合了快速改进的灰度差分法和高精度小波变换法的优点,根据各阶段聚焦评价函数的梯度选择合适的评价函数和镜头移动步长,并且实现了从大步长快速粗扫到小步长精确细调的过渡。实验表明,与传统的应用单一的聚焦评价函数和单一的步长算法相比,该算法在满足自动聚焦精度要求的基础上提高了自动聚焦的速度,可获得良好的聚焦效果。更多还原

【Abstract】 Focusing evaluation function and method of searching apices are important parts in auto-focusing,which directly influences the effect of auto-focus.In order to satisfy the auto-focusing speed and accuracy requirement,a new automatic algorithm is proposed.The algorithm,which combines improved gray scale difference method and high-accuracy wavelet function method,is able to properly select the focusing evaluation function and step length according to the gradients of the focusing evaluation function in each period of the focusing process.It realizes the transition from fast rough adjustment to accurate one.The results of experiment show that compared with the traditional algorithm,the algorithm proposed shortens the focusing time while ensuring the accuracy of focusing.It can achieve favorable effect.更多还原