The Logarithmic Image Processing Model: Connections with Human Brightness Perception and Contrast Estimators

The logarithmic image processing (LIP) model is amathematical framework based on abstract linear mathematicswhich provides a set of specific algebraic and functionaloperations that can be applied to the processing of intensityimages valued in a bounded range. The LIP model has been provedto be physically justified in the setting of transmitted lightand to be consistent with several laws and characteristics ofthe human visual system. Successful application examples havealso been reported in several image processing areas, e.g.,image enhancement, image restoration, three-dimensional imagereconstruction, edge detection and image segmentation.The aim of this article is to show that the LIP model is atractable mathematical framework for image processing which isconsistent with several laws and characteristics of humanbrightness perception. This is a survey article in the sensethat it presents (almost) previously published results in arevised, refined and self-contained form. First, an introductionto the LIP model is exposed. Emphasis will be especially placedon the initial motivation and goal, and on the scope of themodel. Then, an introductory summary of mathematicalfundamentals of the LIP model is detailed. Next, the articleaims at surveying the connections of the LIP model with severallaws and characteristics of human brightness perception, namelythe brightness scale inversion, saturation characteristic, Weber'sand Fechner's laws, and the psychophysical contrast notion. Finally,it is shown that the LIP model is a powerful and tractable framework for handling the contrast notion. This is done througha survey of several LIP-model-based contrast estimators associated with special subparts (point, pair of points,boundary, region) of intensity images, that are justified bothfrom a physical and mathematical point of view.     

超越离合器内星轮对数螺旋楔合面的设计

通过对采用平面楔合面内星轮的超越离合器的受力及磨损对其使用可靠性影响的分析，从而提出了用对数螺旋楔合而代替平面楔合面的设计方案，并对两种方案进行了比较。     

Prediction of the twisting moment and axial force in a circular rubber cylinder for combined extension and torsion based on the logarithmic strain approach

The scope of the present work is the application of a particular class of strain energy function, based on the logarithmic strain, for the prediction of the twisting moment and axial force of a rubber circular cylinder under combined extension and torsion. The strain energy function involves four material parameters three of which are determined by fitting published experimental data from simple tensile and compression tests of natural rubber. One of the parameters of the proposed model has physical meaning, and it is equal to one ninth of the initial modulus of elasticity of the material. Hence, the number of unknown parameters is reduced to three. The logarithmic strain energy function is then applied to a combined extension and torsion problem of a rubber circular cylinder to check its performance for more complicated deformations. The results are compared with corresponding experimental and theoretical solutions available in the literature to validate the proposed model. It is found that the proposed strain energy function apart from predicting the common modes of deformations is also capable to determine more complicated types of deformation. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

测量值量化的时滞系统的输出反馈控制

为了解决无线网络带宽限制的问题,信号在传输之前需要进行量化,但是量化器的引入会给信号带来一定的误差.针对时滞系统,研究测量值量化的基于观测器的输出反馈控制问题.考虑对数量化器,为了研究量化器对系统的影响,引入上行界的方法,将对数量化问题转化成鲁棒不确定问题.为了讨论系统的收敛速度,采用带有衰减系数的Lyapunov函数,得到了闭环系统的指数衰减率.采用线性矩阵不等式(LMI)的方法给出了系统满足指数稳定的充分条件以及控制器和观测器增益的表达式.应用数值仿真证明了本文算法的有效性.     

基于变差函数全局纹理增强的结构相似度图像质量评价

为解决结构相似度算法的图像质量评价缺陷,提出了一种基于变差函数全局纹理增强的结构相似度图像质量评价。该方法首先利用改进的对数变差函数模型提取原图像和失真图像在水平0°、垂直90°和对角45°、135°四个方向的纹理信息特征,然后分别求出对应的纹理增强图像,最后改进SSIM中的结构信息来确定纹理区域的明显失真,计算得到整幅图像的VSSIM值。目前大多数的全参考评价方法不能对数据库中的所有失真类型进行评价,只能对某一类固定的失真类型来评价。本方法对LIVE数据库中的五种失真类型都适用,仿真实验表明,该算法对五种不同失真类型的评价结果具有一定的合理性,并且与主观评价数据库较为一致,其性能也优于其他质量评价模型。     

基于椭圆曲线的盲数字签名及其身份识别

椭圆曲线密码体制以其特有的优越性被广泛用于进行数据加密和构建数字签名方案。同样,它也可以用来构建盲数字签名方案。介绍了椭圆曲线密码体制的相关知识,基于求解椭圆曲线离散对数问题的困难性,设计了一种基于椭圆曲线离散对数问题的盲数字签名方案,并在此基础上设计了一种身份识别协议,该方案可以同时满足盲数字签名的正确性、匿名性、不可伪造性和不可追踪性等特性要求。从理论上分析该方案是安全的,并具有一定的实用价值。     

Web Page Recommendation Using Distributional Recurrent Neural Network

In the data retrieval process of the Data recommendation system, the matching prediction and similarity identification take place a major role in the ontology. In that, there are several methods to improve the retrieving process with improved accuracy and to reduce the searching time. Since, in the data recommendation system, this type of data searching becomes complex to search for the best matching for given query data and fails in the accuracy of the query recommendation process. To improve the performance of data validation, this paper proposed a novel model of data similarity estimation and clustering method to retrieve the relevant data with the best matching in the big data processing. In this paper advanced model of the Logarithmic Directionality Texture Pattern (LDTP) method with a Metaheuristic Pattern Searching (MPS) system was used to estimate the similarity between the query data in the entire database. The overall work was implemented for the application of the data recommendation process. These are all indexed and grouped as a cluster to form a paged format of database structure which can reduce the computation time while at the searching period. Also, with the help of a neural network, the relevancies of feature attributes in the database are predicted, and the matching index was sorted to provide the recommended data for given query data. This was achieved by using the Distributional Recurrent Neural Network (DRNN). This is an enhanced model of Neural Network technology to find the relevancy based on the correlation factor of the feature set. The training process of the DRNN classifier was carried out by estimating the correlation factor of the attributes of the dataset. These are formed as clusters and paged with proper indexing based on the MPS parameter of similarity metric. The overall performance of the proposed work can be evaluated by varying the size of the training database by 60%, 70%, and 80%. The parameters that are considered for performance analysis are Precision, Recall, F1-score and the accuracy of data retrieval, the query recommendation output, and comparison with other state-of-art methods.     

Automatic luminance control summarized

Automotive automatic luminance control concepts are summarized for displays where the ambient illumination is measured and the display luminance is modified to maintain legibility. The most important aspects are reviewed to provide a high‐level overview and insight.     

基于优化Prewitt的高速夜间车道检测算法

针对夜间高速公路,提出识别车道标志线的新型检测算法.该算法采用改进的中值法滤波,基于光密度差的4方向模板对数Prewitt边缘检测预处理图像,得到二值化阈值T. ROI和左右车道线的确定大大减少运算量,结合车道线宽度去除伪车道,采用临时轨迹策略排除光线变化和前方车辆的干扰,最后得到完整清晰的车道线.实验证明该车道检测方法具有快速性、稳定性、准确性.