Image-pair-based deblurring with spatially varying norms and noisy image updating

Chang-Hwan Son, Hyunseung Choo, and Hyung-Min Park

Journal of Visual Communication and Image Representation, vol. 24, no. 8, pp. 1303-1315, Nov. 2013 (SCI, IF: 1.361)

Abstract

This paper presents a deblurring method that effectively restores fine textures and details, such as a tree’s leaves or regular patterns, and suppresses noises in flat regions using consecutively captured blurry and noisy images. To accomplish this, we used a method that combines noisy image updating with one iteration and fast deconvolution with spatially varying norms in a modified alternating minimization scheme. The captured noisy image is first denoised with a nonlocal means (NL-means) denoising method, and then fused with a deconvolved version of the captured blurred image on the frequency domain, to provide an initially restored image with less noise. Through a feedback loop, the captured noisy image is directly substituted with the initially restored image for one more NL-means denoising, which results in an upgraded noisy image with clearer outlines and less noise. Next, an alpha map that stores spatially varying norm values, which indicate local gradient priors in a maximum-a-posterior (MAP) estimation, is created based on texture likelihoods found by applying a texture detector to the initially restored image. The alpha map is used in a modified alternating minimization scheme with the pair of upgraded noisy images and a corresponding point spread function (PSF) to improve texture representation and suppress noises and ringing artifacts. Our results show that the proposed method effectively restores details and textures and alleviates noises in flat regions.

 

Keyword

Image stabilization, Multi-exposure imaging, Spatially varying norm, Alternating minimization, Noise-level estimation, Point sprea, function, Image fusion, Maximum-a-posterior

 

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