An exhaustive criterion for estimating quality of images in electrical impedance tomography with application to clinical imaging

This study proposes a versatile criterion for estimating quality of images in electrical impedance tomography. The point spread function (PSF) is calculated throughout the domain based on the scattering of energy as responses to a small anomaly spirally moved from the centre to the boundary. The proposed PSF is a measure of weighted spatial variance (WSV) of the conductivity over the whole domain. For each element, the weighting factor is a normalized multiplication of the area of that element by its square intensity. The WSV collectively incorporates all image attributes, i.e., spatial resolution, artifact, amplitude response, positioning error and shape deformation. The location of artifacts, which significantly influences reconstructed images in reality, is taken into account as well. The results illustrate that the proposed measure is more tolerant than existing criteria in evaluating performance of EIT systems in both theory and practice.     

Optical multiresolution analysis with spatial localization

Multiresolution analysis is very useful for characterization of textures, segmentation tasks, and feature enhancement. The development of optical methods to perform such procedures is highly promissory for real-time applications. Usually, the optical implementations of multiresolution analysis consist in the decomposition of the input scene in different frequency bands, obtaining various filtered versions of the scene. However, under certain circumstances it could be useful to provide just one version of the scene where the different filters are applied in different regions. This procedure could be specially interesting for biological and medical applications in situations when the approximate localization of the scale information is known a priori. In this paper we present a fully optical method to perform multiresolution analysis with spatial localization. By means of the proposed technique, the multi-scale analysis is performed at once in a unique image. The experimental set-up consist of a double-pass convergent optical processor. The first stage of the device allows the multiple band decomposition, while the second stage confines the information of each band to different regions of the object and recombines it to achieve the desired operation. Numerical simulations and experimental results, which prove the very good performance of the method, are presented.     

Non-texture image inpainting using histogram of oriented gradients

This paper presents a novel and efficient algorithm for non-texture inpainting of images based on using the dominant orientation of local gradients. It first introduces the concept of a new matrix called orientation matrix and then uses it for faster and better inpainting. The process of propagating information is carried out by using a new formulation which leads to much more efficient computations than the previous methods. The gain is both in terms of computational complexity and visual quality. The promising results in contexts of text, scratch, and block loss inpainting demonstrate the effectiveness of the proposed method.     

人脸图像信息可用性影响因素的研究分析

传统的图像质量评估技术通常用于判断图像的整体质量,而不能有效地判断人脸图像信息的可用性.而人脸图像信息可用性评估在安防监控中具有很强的应用价值.提出了人脸图像信息可用性的概念,并提出了通过人脸识别算法来评估该可用性的度量方法.通过采用PCA人脸识别算法模拟仿真,定量地从原理上研究了影响人脸图像信息有用性的关键因素,并通过实验进行了验证.     

一种基于Arnold变换和RSA的图像加密算法

提出一种Arnold变换和RSA相结合的图像加密算法。利用Arnold变换对图像的像素位置进行链式迭代置乱。在对置乱后的图像像素值进行替代和扩散的过程中,采用基于大素数分解的RSA算法,构造一个位置置乱和灰度变换相结合的加密算法。实验仿真结果表明该算法支持变长密钥,具有敏感性强、去相关能力强及抵御统计和已知明文攻击等优点,能够取得很好的加密效果。     

引入零视差缓冲的DIBR改良方法

针对图像部分像素深度值失真,导致图像变形后物体边缘失真的问题,提出了一种引入“零视差缓冲”的方法。首先选取四幅具有不同复杂程度场景的图像,引入零视差缓冲对图像进行变形,其次采用传统图像质量评价体系（结构相似度SSIM和模糊系数K）对得到的图像进行质量评价,最后对比传统DIBR方法和引入零视差缓冲方法得到的视点图中物体边缘的表现。实验结果表明,该方法对于变形图像的SSIM平均提高了4.66%, K平均下降了1.73%。提高了视点图中物体边缘的质量,提高了3D图像的整体质量。     

Molecular Recognition of Carbonyl Compounds by Uranyl-salophen Based Neutral Receptors Driven by Van Der Waals Forces

The complexation of the salophen-uranyl metallocleft 2 and of its half-cleft analogue 3 with enones and other carbonyl compounds was assessed in chloroform by UV-Vis titration and, occasionally, by FT-IR measurements. Complexes with receptors 2 and 3 are in all cases more stable than those with the control unsubstituted uranyl-salophen 1 , showing that in addition to the primary binding force provided by coordination of the carbonyl oxygen to the uranium, a significant driving force for complexation, typically in the range of 2-3 kcal/mol, results from van der Waals interactions of the guest with the aromatic walls. Replacement of the phenyl group in 3 with larger aromatic residues to give 4 and 5 , led to enhanced complex stabilities, due to more extended contact surfaces between host and guest.     

浅海波导界面对点源振速方向的影响

采用“虚源法”分析计算了浅海波导环境中接收点处点源总振速方向与水平面夹角,侧重讨论确定性界面反射对总振速方向的影响。研究结果表明：总振速方向和接收点与声源的水平距离、两者深度,海底、海面特性以及声速剖面等有关。在等声速均匀浅海波导中,由于确定性界面反射的影响,当直达声掠射角为1°～50°时,合成总振速方向偏离直达声方向达1.5°～10.5°,声速剖面呈负梯度时,偏离程度更甚.     

某机载瞄准系统精度评估测试方法

为了评估某型机载瞄准系统的精度,根据飞行试验参数测试需要,提出了通过图像测量与DGPS融合处理方法进行瞄准精度评估的试验方案。该方案利用飞行试验获取的图像数据与其他测量数据相结合,建立精度评估的方法,该评估方法在该机载武器瞄准系统精度评估得到应用,并且可在同类试验课题中推广应用。     

Supramolecular Engineering Strategy to Construct BODIPY-Based White Light Emission Materials

Two kinds of 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY) dyads BDP-OH containing 4-hydroxystyrene groups and BDP-PY bearing pyridinyl units were prepared. In addition, a naphthalene derivative NAP-PY modified by pyridinyl moieties substituent was made. The above three dyads could be used to construct white-light emission (WLE) material by a supramolecular engineering strategy due to their three primary colors of blue, green and red. The supramolecular correlations between the hydroxyl group of BDP-OH and the pyridinyl groups of NAP-PY and BDP-PY were confirmed by ¹H NMR titration, 2D NOESY and FTIR. A fluorescence monitor application was carried out based on the realization of WLE. This work might be useful for designing other WLE supramolecular systems and image display.