Quality-guided phase unwrapping implementation: an improved indexed interwoven linked list.

Abstract

Quality-guided phase unwrapping (QGPU) is a widely used technique, and an adjoin list plays a very important role in the QGPU process. Indexed interwoven linked list (I2L2) is a data structure for implementing the adjoin list. In this paper, we propose three improvements on the I2L2. The first improvement is resumed searching, which records the highest nonempty level in the I2L2 and reduces the computational redundancy; the second is an adaptive mapping between the quality values and the I2L2 levels, which reduces the effect of concentrated quality value distribution. Last, I2L2-H, a new variant of the I2L2 combining the advantages of both the I2L2 and heap, is developed. With these three improvements, the improved I2L2 is over 6 times faster than the original one in the best cases, and it can process large phase maps in almost real time.