干涉图去包裹位相的二次校正

相位去包裹是移相干涉技术中关键的组成部分。一些去包裹算法在处理具有较多无效成像点的干涉图时，会在处理结果中引入较大的算法误差。提出了通过对去包裹位相进行二次校正的方法，实现去包裹位相算法误差的有效消除。文中通过基于DCT变换的最小二乘去包裹算法为例进行了说明，并通过一光学平晶表面的处理结果对方法进行了验证。

Double Revising after Phase Unwrapping of Interference Patterns

Phase unwrapping is a key segment in phase-stepping technique. A big error will occur when using some phase unwrapping algorithms to process the interference patterns with many invalid imaging points. The paper presents a double revising method to process unwrapping phase to remove its algorithm error. The paper uses the least-squares algorithm by the discrete cosine transform (DCT) as an example to explain this method. The test results of an optical flat testify its correctness.