基于CCD采集的Mach-Zehnder干涉条纹图的处理算法

Mach-Zehnder干涉仪适用于研究气体密度迅速变化的状态。由于气体折射率的变化与其密度的变化成正比,而折射率的变化将使通过气体的光线有不同的光程,因此可通过干涉臂变化对干涉条纹图像效果的影响得到气体密度。实测中,采用图像采集卡和CCD来接收Mach-Zehnder干涉仪产生的条纹图像,再通过计算机对条纹图像的条纹间距进行处理,从而得到气体密度的变化状态。从光干涉理论出发,对Mach-Zehnder干涉条纹图像特征进行了分析,建立了Mach-Zehnder干涉条纹的数学模型,并根据此模型设计了处理Mach-Zehnder干涉条纹图像的算法。算法包括图像的预处理(即图像的噪声提取)、图像的二值化及图像的细化。

Arithmetic to Process the Mach-Zehnder Inter ference Fringe Patterns Collected by CCD

Mach-Zehnder interferometer is suitable for studing the density change of gas. The variation of refractive index makes the beams getting through gas have different optical paths. Therefore, the density of gas can been acquired by changing the interference arm to affect interference fringe patterns. In real measurement,the fringe patterns generated by Mach-Zehnder interferometer are collected by frame frabber and CCD, then the fringe spaces are processed by a computer to get the gas density change. This paper is base on light interference theory, analyses the property of Mach-Zehnder fringe patterns and establish a math model. According to the math model, an arithmetic was designed to deal with Mach-Zehnder interference fringe patterns. The arithmetic includes image preprocess(i.e. noise extraction of image),gray image binarization and fringe pattern sharpening.