Application Of Super-resolution Technique Based On Sub-pixel Scanning In X-ray Microscopy

X-ray microscope can be used as a tool for nondestructive detection of sample' internal structures.It has been widely used in advanced manufacture,material,biomedical and so on.The spatial-resolution of X-ray microscope own the accuracy of micro-scale,and furtherly improving the resolution is one of the focus problem.At present,there are two ways to improve image resolution: one way is to improve the system's hardware performance and the other way is studying new super-resolution reconstruction algorithms.As the hardware process is approaching the bottleneck,it is very difficult to improve the resolution by developing more accurate hardware,and it also brings some problems.Therefore,developing super-resolution scanning and reconstruction method on the existing hardware show great significance.In this paper,super-resolution techniques are applied to the X-ray microscope system to improve imaging performance,and the main work is as follows:1.Introduce the history and the research status of super-resolution imaging technology.Analyze and summarize the methods to improve the spatial resolution of X-ray microscopy and the existing problems.And the super-resolution technology used in X-ray microscope has been come up with.2.The mathematical and physical basis of super-resolution technology,the observation model and the basic steps of super-resolution reconstruction are introduced in detail.According to the basic requirements of reconstruction,the appropriate motion registration algorithm and super-resolution reconstruction algorithm are investigated and summarized.3.Simulation and comparison of motion registration algorithm and superresolution reconstruction algorithm.According to the mathematical theory of algorithm,simulation program is wrote,the precision and speed of Keren algorithm and phase correlation method are compared,and different window function to phase correlation method are added and the registration accuracy are compared.The influence of motion registration accuracy on super-resolution reconstruction accuracy is simulated and analyzed.Simulation and real data are used to simulate and compare different superresolution reconstruction algorithms.And the suitable algorithm for the X-ray microscope is selected.4.The super-resolution experiment of X-ray microscope has been operated.All parts of the experimental system are introduced.The stability of focal spot of X-ray source,the mechanical stability of the system are analyzed via experiments.The appropriate modulation and demodulation mode are derivated.The influence of superresolution results with different sub-pixel subdivision schemes,and the reconstruction results under different Magnification are compared.It is proved by experiments that the method of super-resolution technique is significant to improve the resolution of X-ray microscope.5.Evaluate the quality of the super-resolution image qualitatively and quantitatively,through contrast noise ratio and modulation transfer function.Finally,the instability of the system is analyzed by statistical method,which shows the reliability of the experiment.