A Space-Variant Deblur Method for Focal-Plane Microwave Imaging

Abstract

In the research of passive millimetre wave (PMMW) imaging, the focal plane array (FPA) can realize fast, wide-range imaging and detection. However, it has suffered from a limited aperture and off-axis aberration. Thus, the result of FPA is usually blurred by space-variant point spread function (SVPSF) and is hard to restore. In this paper, a polar-coordinate point spread function (PCPSF) model is presented to describe the circle symmetric characteristic of space-variant blur, and a log-polar-coordinate transformation (LPCT) method is propagated as the pre-processing step before the Lucy–Richardson algorithm to eliminate the space variance of blur. Compared with the traditional image deblur method, LPCT solves the problem by analyzing the physical model instead of the approximating it, which has proved to be a feasible way to deblur the FPA imaging system.

Linear Revolution-Invariance: Modeling and Deblurring Spatially-Varying Imaging Systems

“…However, a significant portion of optical theory is developed under the assumption of rotational symmetry; for example, the analysis of an optical system while considering only a single plane is only possible assuming rotational symmetry. The use of rotational symmetry and polar transformations for deblurring arises in modeling motion blur [26,27], suppressing radial variance [28], and segmenting the FoV into shift-invariant radial segments [29][30][31][32]. Additionally, ray models have been developed using Seidel coefficients [33].…”

Blind Image Deconvolution Algorithm Based on Sparse Optimization with an Adaptive Blur Kernel Estimation

“…Therefore, recovering an approximated latent image from a blurred observation is essential for improving the performance of an imaging system, in addition to having several applications [4][5][6]. One approach to handle this problem is to build parameterized models for specific blur types, i.e., employ motion length and angle to describe a motion blur, the radius of a disk to model the defocus blur, and a Gaussian model to simulate the atmospheric turbulence blur.…”