一种基于能量和熵的自动聚焦算法  

Implementation of an Automatic Focusing Algorithm Based on Spatial High Frequency Energy and Entropy

作　　者：康宗明[1] 张利[1] 谢攀[1] 

机构地区：[1]清华大学电子工程系,北京100084

出　　处：《电子学报》2003年第4期552-555,共4页Acta Electronica Sinica

基　　金：国家自然科学基金 (No .60 1 72 0 2 7)

摘　　要：本文提出了一种基于能量和熵的自动聚焦算法 .在讨论镜头系统造成图像模糊原理的基础上 ,提出以空域高频能量和熵作为图像清晰度判据并详细分析了判据性能 ,针对传统的MCS聚焦流程所固有的局限性 ,引入了方向测试帧概念 ,通过联合使用多种清晰度判据以及步长的自适应调整策略提高了自动聚焦的可靠性、聚焦速度以及聚焦灵敏度 .本算法应用在作者开发的高清晰度图像采集系统中 ,试验结果证明所提出的判据和实际聚焦过程吻合 。A new advanced automatic focusing algorithm is proposed. After discussing the principle how image is blurred by the lens system, we presented spatial high frequency energy and entropy as the sharpness criteria and analyzed their performance. Aiming at the limitation of conventional MCS, the concept of direction-test frame is proposed. The reliability, speed and sensitivity of auto focus are enhanced by using more definition criteria together and self-adjust step. The proposed algorithm has been successfully tested to be effective on a high definition image processing system developed by the authors. Experimental results demonstrate that the new criteria work according to the fact and the proposed algorithm.

关 键 词：自动聚焦 空域高频能量判据 熵判据 MCS 方向测试帧 

分 类 号：TP274[自动化与计算机技术—检测技术与自动化装置]