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Image Blind Deblurring Using an Adaptive Patch Prior
Tsinghua Science and Technology 2019, 24 (2): 238-248
Published: 31 December 2018
Downloads:27

Image blind deblurring uses an estimated blur kernel to obtain an optimal restored original image with sharp features from a degraded image with blur and noise artifacts. This method, however, functions on the premise that the kernel is estimated accurately. In this work, we propose an adaptive patch prior for improving the accuracy of kernel estimation. Our proposed prior is based on local patch statistics and can rebuild low-level features, such as edges, corners, and junctions, to guide edge and texture sharpening for blur estimation. Our prior is a nonparametric model, and its adaptive computation relies on internal patch information. Moreover, heuristic filters and external image knowledge are not used in our prior. Our method for the reconstruction of salient step edges in a blurry patch can reduce noise and over-sharpening artifacts. Experiments on two popular datasets and natural images demonstrate that the kernel estimation performance of our method is superior to that of other state-of-the-art methods.

Open Access Issue
Sparse Representation over Shared Coefficients in Multispectral Pansharpening
Tsinghua Science and Technology 2018, 23 (3): 315-322
Published: 02 July 2018
Downloads:22

The pansharpening process is for obtaining an enhanced image with both high spatial and high spectral resolutions by fusing a panchromatic (PAN) image and a low spatial resolution multispectral (MS) image. Sparse Principal Component Analysis (SPCA) method has been proposed as a pansharpening method, which utilizes sparse coefficients and over-complete dictionaries to represent the remote sensing data. However, this method still has some drawbacks, such as the existence of the block effect. In this paper, based on SPCA, we propose the Sparse over Shared Coefficients (SSC), in which patches are extracted with a sliding distance of 1 pixel from a PAN image, and the MS image shares the sparse representation coefficients trained from the PAN image independently. The fused high-resolution MS image is reconstructed by K-SVD algorithm and iterations, and residual compensation is applied when the down-sampling constraint is not satisfied. The simulated experiment results demonstrate that the proposed SSC method outperforms SPCA and improves the overall effectiveness.

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