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Blind image deblurring tries to restore a blurred image to a clear image without the blurring kernel known in advance, which is widely required in applications such as computer vision and medical image processing. With regard to this, the key issues here are to accurately estimate the blurring kernel for deconvolution of a blurred image, and avoid the ringing artifacts in the restored image, which are both related to high-quality detection of edge information in the blurred image. Though much endeavor has been made, it is still difficult to extract edge information well in blurred images and lacks investigation how edge information causes ringing artifacts. In this paper, we make a study on this and develop novel measures to optimize edge extraction and determine suitable width and weights for the extracted edges for reinforcing their use in deblurring, by which image deblurring can be improved with ringing artifacts considerably suppressed. Experimental results demonstrate our improvements over the existing methods. [ABSTRACT FROM AUTHOR]

A systematic investigation and comparison of the photoluminescence (PL) quantum yields of six erbium(III) organic complexes are reported. We demonstrated that the PL quantum yield could be significantly improved by getting rid of OH and CH groups in the complexes. Moreover, perfluooctanoic acid with neither OH nor CH groups was used as a ligand to form complex with Er3+. The quantum yield of the newly synthesized erbium(III) complex was found to be as high as 2%, 100 times higher than ever reported. [ABSTRACT FROM AUTHOR]

Monolithic Er-doped silica xerogels with erbium content of 5000 ppm were prepared by sol-gel technique. Samples were densified by thermal treatment in O2/CCl4 environment. The 1.55 μm photoluminescence lifetimes after annealing at different temperatures were measured, together with the relative content of hydroxyl groups inside the samples. It was found that hydroxyl groups can be removed by CCl4 effectively. Consequently the photoluminescence lifetime of the samples increased significantly after the removal of hydroxyl groups. For sample treated in O2/CCl4 at 900°C, fluorescence lifetime as long as 6ms was obtained and is pretty stable when the sample is kept in ambient air. [ABSTRACT FROM AUTHOR]