Automatic focusing system of micro-vision based on image analysis
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摘要: 开发了用于显微视觉对准装配的自动聚焦系统.系统采用基于图像空域分析的聚焦方式.首先通过对比,选择计算量最小的y向一阶差分算子作为系统的聚焦测度;然后通过合理选择聚焦窗口,优化了聚焦效果;最后提出一种不同于通常爬山法的自动聚焦策略,实现该方法的核心是建立聚焦函数与离焦量之间的函数关系,本系统采用3次样条插值估算未测聚焦函数值的办法构建了这种函数关系.应用结果表明该系统自动聚焦的准确性与实时性满足要求.Abstract: An automatic focusing system of micro-vision for micro alignment assembly was developed. The system was based on spatial domain analysis. First-order differential operator in y direction was choosed as focusing evaluation function to realize autofocus quickly and accurately. Processing the image in a choosed focusing window was presented to optimize focusing effect. A new focusing algorithm was put forward, which is different from hill climbing searching algorithm(HCSA). The key factor of the algorithm is establishing the relation between defocus values and focusing evaluation. Cubic spline interpolation was adopted to establish focusing relation function to realize the algorithm effectively. It proves the system can realize autofocus accurately and quickly.
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Key words:
- vision /
- image analysis /
- auto-focus /
- focusing evaluation /
- focusing algorithm
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