Weighted-phase-gradient-based quality maps for two-dimensional quality-guided phase unwrapping

Abstract The two-dimensional phase unwrapping plays an important role in phase measurement applications. This paper proposes a simple but effective method to construct reliable quality maps for two-dimensional quality-guided phase unwrapping. A new group of reliable quality maps based on weighted-phase-gradient is proposed to overcome the shortcomings of traditional phase-gradient quality maps. When a quality map of a wrapped phase image is generated, the weighted gradient information of neighborhood pixels of the wrapped phase image is used to determine the quality of the current pixel. Thus the quality of the wrapped phase data can be accurately reflected in the resulting quality map. In order to evaluate the reliability, effectiveness and advantages of the proposed quality maps, a new performance evaluation model for quality maps is also proposed. Unwrapped results demonstrate that the weighted-phase-gradient-based quality maps are excellent indicators of the phase quality and can be used to retrieve a reliable phase profile in quality-guided phase unwrapping process.