Multichannel blind CT image restoration via variable splitting and alternating direction method

Sun, Yu; Zhang, Liyi; Zhang, Haiyan; Zhang, Jingyu

doi:10.1007/s12209-015-2667-6

Cited by 3 publications

(1 citation statement)

References 36 publications

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“…Multiple sets of bone interfaces and the iterative strategy [4][5][6] were utilized to estimate the point spread function. Blind equalization algorithm was applied to the two-dimensional CT blind image restoration [7][8][9]. Combining with the dimension reduction theory and orthogonal transform, without any information of degradation, only the features of degraded images were utilized to estimate the clear image.…”

Section: Introductionmentioning

confidence: 99%

Double regularization medical CT image blind restoration reconstruction based on proximal alternating direction method of multipliers

Zhang

Sun

Zhang

et al. 2017

J Image Video Proc.

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To solve the problem of CT image degradation, a double regularization CT image blind restoration reconstruction method was proposed. The objective function including both a clear image and point spread function was established. To avoid the over-smoothing phenomenon and protect the detail, the objective function includes two constraint regularization terms. They are total variation (TV) and wavelet sparsity respectively. The objective function was solved by the alternating direction multiplier method (ADMM), and the optimal solution was obtained. Firstly, the CT image blind restoration reconstruction was decomposed into two sub-problems: reconstructed image estimation and point spread function estimation. Furthermore, each sub-problem can be solved by the proximal alternating direction method of multipliers. Finally, the CT image blind restoration reconstruction was realized. The experimental results show that the proposed algorithm takes into account the degradation effect of projection data, and the proposed algorithm is superior to other existing algorithms in the subjective visual effect. At the same time, in the aspect of objective evaluation, the proposed algorithm improves the objective image quality metrics such as peak signal-to-noise ratio (PSNR), structural similarity index metric (SSIM), and universal image quality index (UIQI).

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Section: Introductionmentioning

confidence: 99%

Double regularization medical CT image blind restoration reconstruction based on proximal alternating direction method of multipliers

Zhang

Sun

Zhang

et al. 2017

J Image Video Proc.

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Improving Sparse Compressed Sensing Medical CT Image Reconstruction

Zhang

Teng

Bai

2019

Aut. Control Comp. Sci.

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Evolutions of Oil Generation and Expulsion of Marine-Terrestrial Transitional Shales: Implications From a Pyrolysis Experiment on Water-Saturated Shale Plunger Samples

et al. 2021

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Shale reservoirs are characterized by self-generation and self-accumulation, and the oil generation and expulsion evolution model of organic-rich shales is one of important factors that obviously influence the enrichment and accumulation of shale oil and gas resources. At present, however, relevant studies on marine-terrestrial transitional shales are inadequate. In this study, a pyrolysis experiment was performed on water-saturated marine-terrestrial transitional shale plunger samples with type Ⅱb kerogen to simulate the evolutions of oil generation and expulsion. The results indicate that marine-terrestrial transitional shales have wider maturity ranges of oil generation and expulsion than marine and lacustrine shales, and the main stages of oil expulsion are later than those of oil generation, with corresponding Ro values of 0.85%–1.15% and 0.70%–0.95%, respectively. Although the oil generation and expulsion process induced a fractionation in compositions between the expelled and retained oils, both the expelled and retained oils of marine-terrestrial transitional shales are dominated by heavy compositions (resins and asphaltenes), which significantly differs from those of marine and lacustrine shales. The kerogen of marine-terrestrial transitional shales initially depolymerized to transitional asphaltenes, which further cracked into hydrocarbons, and the weak swelling effects of the kerogen promoted oil expulsions. The oil generation and expulsion evolutions of these shales are largely determined by their organic sources of terrigenous higher organisms. This study provides a preliminary theoretical basis to reveal the enrichment mechanism of marine-terrestrial transitional shale oil and gas resources.

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Multichannel blind CT image restoration via variable splitting and alternating direction method

Cited by 3 publications

References 36 publications

Double regularization medical CT image blind restoration reconstruction based on proximal alternating direction method of multipliers

Double regularization medical CT image blind restoration reconstruction based on proximal alternating direction method of multipliers

Improving Sparse Compressed Sensing Medical CT Image Reconstruction

Evolutions of Oil Generation and Expulsion of Marine-Terrestrial Transitional Shales: Implications From a Pyrolysis Experiment on Water-Saturated Shale Plunger Samples

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