Quick solving method on basis of light intensity transfer equation of discrete cosine transform

Abstract

The invention discloses a quick solving method on the basis of a light intensity transfer equation of discrete cosine transform. The method comprises the following steps of firstly, placing a diaphragm on the plane to be detected, acquiring three light intensity images, i.e. an under-focus light intensity image, a focusing light intensity image and an out-of-focus light intensity image, and performing numerical value difference on the under-focus light intensity image and the out-of-focus light intensity image to obtain an axial differential signal of light intensity; secondly, solving the inverse laplace of the axial differential signal of light intensity by using discrete cosine transform, on the basis of discrete cosine transform, solving the gradient of the inverse laplace of the axial differential signal of light intensity, dividing the gradient by the focusing light intensity image, and solving a divergence operation; finally, solving the inverse laplace on the result obtained in the step 3 by using discrete cosine transform, thus the solution, i.e. phase distribution to be solved, of the light intensity transfer equation is obtained. The precision of phase recovery is improved, the method is very simply and efficient, and the required external storage amount is also very low.

Description

technical field [0001] The invention belongs to phase recovery and quantitative phase imaging technology in optical measurement, in particular to a fast solution method of light intensity transmission equation based on discrete cosine transform. Background technique [0002] Phase recovery is an important topic in optical measurement and imaging technology, and phase imaging technology is playing an important role in both biomedical and industrial detection fields. Throughout the progress of optical measurement for nearly half a century, the most classic phase measurement method should be none other than interferometry. However, the disadvantages of interferometry are also very obvious: interferometry generally requires a highly coherent light source (such as a laser), which requires a more complex interferometric device; the introduction of an additional reference optical path leads to very harsh requirements for the measurement environment; The speckle coherent noise intr...

AI Technical Summary

Problems solved by technology

Usually, simple periodic boundary conditions or uniform Dirichlet boundary conditions and Neumann boundary conditions are used. When these simplified boundary conditions cannot be satisfied, the accuracy of the recovered phase will be greatly affected

On the other hand, the algorithm solution efficiency is low, and it is difficult to meet the occasions of high-speed and real-time applications.

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