全反射现象中半明半暗视场的分界线位置的测量  

Measurement of the Position of Boundary Between Bright and Dark Areas in the Phenomenon of Total Reflection

作　　者：华俊[1] 赵辉[1] 洪海涛[1] 陶卫[1] 

机构地区：[1]上海交通大学信息检测技术与仪器系,上海200030

出　　处：《计算机测量与控制》2004年第5期406-407,422,共3页Computer Measurement &Control

摘　　要：和平行光照射遮光物体产生的实边缘相比,全反射现象中半明半暗视场的分界线处的虚边缘情况更为复杂。使虚边缘质量有明显下降的主要因素有3个:光的色散、高频噪声和CCD光敏元处于临界状态所带来的问题。使用基于图像处理的测量方法,采用CCD作为成像器件,获取虚边缘附近的灰度图像。应用改进后的基于一阶微分期望值的亚像素边缘检测算法,可以快速、精确地检测到边缘的位置。经过实验验证,该方法的测量精度优于1个像素,并且具有良好的重复性。Compared with the real edge generated when parallel beam illuminates an object, the virtual edge between bright and dark areas in the phenomenon of total reflection is more complex. There are mainly 3 factors causing obvious decrease of the quality of virtual edge: chromatic dispersion, high-frequency noises ane problems caused by CCD pixels in critical state. A new measuring method based on image processing is proposed. We used CCD as the imaging device to obtain the gray level image of the virtual edge. Using improved sub-pixel edge detecting algorithm based on the expectation of first-order derivatives, we can fast and precisely detect the edge position. This method has been proved in a series of experiments to be effective and stable. Its measuring precision gets below one pixel.

关 键 词：全反射 CCD 边缘检测 图像测量 分界线位置 高频噪声 色散 图像处理 

分 类 号：TP274.2[自动化与计算机技术—检测技术与自动化装置]