A Novel Image Restoration Approach Based on Model for Fresnel Zone Plate Imaging System

Fresnel zone plate (FZP) is predominant diffraction optics element for space-based telescope with large diameter. However, the imaging quality of FZP is insufficient to meet the requirement of space imaging owing to the multiple orders diffraction characteristics of FZP, and wavefront aberrations. In this paper an approach based-on imaging model and cuckoo searching is given to acquire the optimum point spread function (PSF), and to improve image quality. The initial values of PSF and diffraction efficiency in cuckoo searching are obtained, when the lab system of FZP imaging is set up. The image restoration experiments are completed according to imaging model with the optimum parameters. The result shows that the values of four kind metrics, standard error, image gradient, image contrast, and natural quality evaluator are improved. The imaging quality of FZP imaging system is evidently prompt, especially in image details and gray contrast. Therefore, the image restoration method is applicable in FZP imaging system with low complexity and real time, especially for the prepossessing for on-line imaging system with wavefront sensor-less adaptive optics.