Image Deblurring via Enhanced Low-Rank Prior.

Low-rank matrix approximation has been successfully applied to numerous vision problems in recent years. In this paper, we propose a novel low-rank prior for blind image deblurring. Our key observation is that directly applying a simple low-rank model to a blurry input image significantly reduces the blur even without using any kernel information, while preserving important edge information. The same model can be used to reduce blur in the gradient map of a blurry input. Based on these properties, we introduce an enhanced prior for image deblurring by combining the low rank prior of similar patches from both the blurry image and its gradient map. We employ a weighted nuclear norm minimization method to further enhance the effectiveness of low-rank prior for image deblurring, by retaining the dominant edges and eliminating fine texture and slight edges in intermediate images, allowing for better kernel estimation. In addition, we evaluate the proposed enhanced low-rank prior for both the uniform and the non-uniform deblurring. Quantitative and qualitative experimental evaluations demonstrate that the proposed algorithm performs favorably against the state-of-the-art deblurring methods.

Modeling of electrophysiology and simulation of ECG under ischemic condition in human ventricular tissue / 生物医学工程学杂志

In this paper, to analyze the functional influence of ischemia on cardiac cell electrical activity and subsequently on ventricular electrical wave conduction, a human ventricular ischemic model was developed, which took into account three major pathophysiological components of ischemias hyperkalaemia, acidosis, and anoxia. This model simulated the action potential (AP) propagations of endocardial, midmycardial and epicardial cells with different levels of ischemia, and the influence of each factor on cell AP was analyzed. Finally the ECG waveform under ischemia was quantified by using a 2D model of human left ventricular tissue based on the anatomical structure of human heart. The experimental results showed that under ischemia action potential durations (APD) were reduced. In most cases, the larger the size of ischemic region or the more severe the ischemic level, the more dramatic the changes in the amplitude of ST-T wave were observed. For the three components of ischemia, hyperkalaemia was the dominant contributor to ST-T wave changes, which was in agreement with the results obtained on animal models.