干涉条纹周期是干涉精密测量中的一个较为重要的参数。为了可以简单快速而不失准确性地测量条纹周期，采用了图像处理实现干涉条纹周期测量的较为简单实用的算法。通过MATLAB平台设计相应的图像数据处理软件，分析影响条纹周期测量精度的因素，给出处理过程对条纹倾斜度的要求，并应用于相板的位相的定量检测，获得了相板的位相大小。结果表明，测量相位精度达λ／20～λ／50或π／10～π／25。这一结果对位相物体的厚度和折射率的测量有很大的帮助。

The period of interference fringes is an important parameter in precision measurement. In order to detect the period of interference fringes simply and fast but not inaccurately,a simpler and practical digital image processing algorithm was adopted to detect the period of interference fringes. The image data processing software was designed on the MATLAB platform and the factors affecting the measurement accuracy of the period of fringes were analyzed. The demand of the fringes inclination was given. The algorithm was used in the detection of phase-plate,and the phase of the phase-plate was acquired. The precision of phase detection reached λ/20 ～λ/50 orπ/10 ～π/25.This result is largely helpful to the thickness and refractive index detection of the phase object.