Connections between transport of intensity equation and two-dimensional phase unwrapping

TL;DR

This paper explores the relationship between the transport of intensity equation-based phase unwrapping method and the standard least squares algorithm, highlighting similarities and additional numerical errors involved.

Contribution

It reveals the connection between TIE-based phase unwrapping and the least squares method, clarifying the source of numerical errors in the process.

Findings

TIE-based unwrapping is related to least squares unwrapping.

Numerical errors are present in the TIE approach.

The study clarifies the connection between different phase unwrapping methods.

Abstract

In a recent publication [Appl. Opt. 55, 2418 (2016)], a method for two-dimensional phase unwrapping based on the transport of intensity equation (TIE) was studied. We wish to show that this approach is associated with the standard least squares phase unwrapping algorithm, but with additional numerical errors.