研究了图像处理的自动调焦方法在机载光电成像设备中的应用。提出了基于图像斜边、水平和垂直边缘检测的调焦评价算子——Bevel算子和Mix算子。选取边缘检测算子和卷积算子分别作为调焦粗搜索和精搜索阶段的清晰度评价算子,设计了适合自动调焦的隔行隔列调焦区域选择方法。采用了变步长爬山搜索法、局部全局搜索法和综合搜索法3种调焦控制策略，使用调焦行程为131步，焦深为2步的变焦镜头，其调焦时间分别从全局搜索法的37 s缩短至3~4 s、4~6 s和3~5 s。实验结果表明，该方法能够满足机载光电成像设备的调焦实时性和精确性要求。

Two new focus measure methods (Bevel and Mix operators) derived from gradient edge detection were proposed. The Bevel and Mix operators and correlation operator were respectively chosen as the focus measure method of coarse search and fine search. A new method of selecting suitable focusing region was presented. Then, mountain climbing search strategy with variable step (MCS), local-global search strategy (LGS) and general search strategy (GES) were proposed. Using a lens with focus length of 130 steps and focus depth of 2 steps, the three search strategies can shorten the focusing time from the full searchs 37 s to 3~4 s ,4~6 s and 3~5 s respectively. The experimental results show that, the method can meet the real-time and accurate requirements of airborne electro-optical imaging device.