Research Of Phase Unwrapping Based On Improved Minimum Cost Flow

Digital holographic microscopy has become one of the research hotspots in the field of optical measurement in recent years with its good three-dimensional dynamic measurement capability.The quality of two-dimensional phase unwrapping is directly related to the accuracy of digital holographic microscopic measurement results.It is also the main source of error.Therefore,achieving accurate and efficient phase unwrapping is a prerequisite for obtaining high-precision digital holographic microscopic measurements.This dissertation focuses on phase reconstruction in digital holographic microscopy.The main contents include:(1)The reasons for the formation of the package phase and the basic principle of the phase unwrapping are studied,as well as the preconditions for obtaining the correct unwrapping phase.The roots of the phase unwrapping error are clarified,and the two ideas of reducing the error and improving the phase unwrapping accuracy are summarized.The method of detecting the residual point in the phase map and generating the mass map from the phase map is introduced.(2)By analyzing the error source and operation efficiency of phase unwrapping,an improved cost function is proposed,which is the weighting matrix obtained by combining the phase quality map and the residual point map.The residual point and the phase data quality of the different regions are fully considered.The effect of unwrapping the results.(3)The simulation and experiment are combined to analyze the anti-noise performance of the minimum cost flow phase unwrapping algorithm based on the improved cost matrix.The superiority of the minimum cost flow phase unwrapping algorithm based on the improved cost matrix in digital holographic microscopy is verified.And the scope of application of the algorithm is clarified.The work of the thesis provides support for real-time and accurate measurement of offaxis image digital holographic micro-measurement system.The algorithm will be further optimized to realize the development of measurement platform to industrialization and commercialization.