POCS-based algorithm for restoring colour-quantised images

The paper studies the restoration of colour-quantised images. Restoration of colour-quantised images is rarely addressed in the literature, and direct applications of existing restoration techniques are generally inadequate to deal with this problem. The authors propose a POCS-based restoration algorithm specific to colour-quantised images, which makes a good use of the available colour palette to derive useful a priori information for restoration. The proposed restoration algorithm is shown to be capable of improving the quality of a colour-quantised image to a certain extent.     

面向事件相关电位成分的稀疏字典构建方法

利用稀疏分解来研究EEG信号是一种新兴的可靠的方法。常见的稀疏字典学习算法中,K-SVD算法得到了比较广泛的应用。但是利用K-SVD算法获得的字典原子很难完整的包含EEG信号中的事件相关电位（ERP）成分,通常样本中的ERP成分都会分布在大量原子中。本文提出把常用的K-SVD算法基础结合稀疏性能指标作为约束条件,解决稀疏字典难以与ERP成分对应的问题,并给出利用该算法进行ERP分析的步骤。通过在一个基于听觉刺激的公开数据集上使用本文的方法,成功地获得了包含完整目标ERP成分的字典原子,证明了方法的可行性。      

Architecture of an all-optical circuit-switched multistageinterconnection network

An architecture of an all-optical multistage interconnection network is proposed. The network supports a circuit-switching model of communication and can provide parallel optical paths among input and output ports. It uses an address-based routing algorithm for path setup which, due to its decentralized nature, makes this network suitable for designing high-speed switching systems. These switches are commonly used in telephony and multiprocessor systems. The proposed architecture uses bistable optical devices, such as interference filters, as essential components of its switching modules. Since these devices can be easily fabricated, the implementation of this architecture is feasible. Various design issues related to optical clock generation, its distribution, data synchronization, and intensity restoration are also discussed     

Regularised restoration of vector quantisation compressed images

The authors study the application of image restoration technology in improving the coding performance of a vector quantisation (VQ) image compression codec. Restoration of VQ-compressed images is rarely addressed in the literature, and direct applications of existing restoration techniques are generally inadequate to deal with this problem. A restoration algorithm is proposed, specific to VQ-compressed images, that makes good use of the codebook to derive useful a priori information for restoration. The proposed restoration algorithm is shown to be capable of improving the quality of a VQ-compressed image to a much greater extent, compared with other existing restoration approaches. As no extra information, other than the codebook, is required to carry out the restoration with the proposed algorithm, no transmission overhead is necessary and hence, it can be fully compatible with any VQ codec when used to improve coding performance     

A passive protected self-healing mesh network architecture andapplications

The self-healing mesh network architecture using digital cross-connect systems (DCSs) is a crucial part of an integrated network restoration system. The conventional DCS self-healing networks using logical channel protection may require a large amount of spare capacity for network components (such as DCSs) and may not restore services fast enough (e.g., within 2 s). The authors propose a passive protected DCS self-healing network (PPDSHN) architecture using a passive protection cross-connect network for network protection. For the PPDSHN architecture, network restoration is performed in the optical domain and is controlled by electronic working DCS systems. Some case studies have suggested that the proposed PPDSHN architecture may restore services within a two-second objective with less equipment cost than the conventional DCS self-healing network architecture in high-demand metropolitan areas for local exchange carrier networks. The proposed PPDSHN architecture may apply to not only the centralized and distributed control DCS network architectures, but also asynchronous, SONET and ATM DCS networks. Transparency of line rates and transmission formats makes the PPDSHN network even more attractive when network evolution is a key concern of network planning     

A POCS-based restoration algorithm for restoring halftoned color-quantized images.

This paper studies the restoration of images which are color-quantized with error diffusion. Though there are many reported algorithms proposed for restoring noisy blurred color images and inverse halftoning, restoration of color-quantized images is rarely addressed in the literature especially when the images are color-quantized with halftoning. Direct application of existing restoration techniques are generally inadequate to deal with this problem. In this paper, a restoration algorithm based on projection onto convex sets is proposed. This algorithm makes use of the available color palette and the mechanism of a halftoning process to derive useful a priori information for restoration. Simulation results showed that it could improve the quality of a halftoned color-quantized image remarkably in terms of both SNR and CIELAB color difference metric.     

Digital restoration of scintigraphic images by a two-step procedure

A two-step procedure for restoring scintigraphic images is described. The first step uses a local-statistics algorithm for improvement in signal-to-noise ratio by smoothing the Poisson noise. The second step aims at improvement in spatial resolution by removing the linear blur using the iterative restoration algorithm. We present some results of computer simulations and restoration of scintigraphic images that demonstrate the effectiveness of the proposed procedure.     

Automatic Artefact Removal from Event-related Potentials via Clustering

This paper outlines a method for automatic artefact removal from multichannel recordings of event-related potentials (ERPs). The proposed method is based on, firstly, separation of the ERP recordings into independent components using the method of temporal decorrelation source separation (TDSEP). Secondly, the novel lagged auto-mutual information clustering (LAMIC) algorithm is used to cluster the estimated components, together with ocular reference signals, into clusters corresponding to cerebral and non-cerebral activity. Thirdly, the components in the cluster which contains the ocular reference signals are discarded. The remaining components are then recombined to reconstruct the clean ERPs.     

A simulated annealing restoration algorithm for restoring halftoned color-quantized images

Restoration of color-quantized images is rarely addressed in the literature especially when the images are color-quantized with halftoning. Most existing restoration algorithms are generally inadequate to deal with this problem as they were proposed for restoring noisy blurred images. In this paper, a restoration algorithm based on simulated annealing is proposed to solve the problem. This algorithm makes a good use of the available color palette and the mechanism of a halftoning process to derive useful a priori information for restoration. Simulation results show that it can improve the quality of a halftoned color-quantized image remarkably in terms of both SNR and CIELAB color difference metric. The subjective quality of the restored images can also be improved.     

Image restoration method based on fractional variable order differential

In this paper, we study image restoration problem by using fractional variable order differential technique. Our idea is to make use of fractional order differential diffusion equation of evolution procedure into the image restoration problem. An image often exists different low-frequency and high-frequency components, such as flat, texture and edge, etc. Because fractional order differential can enhance the high-frequency components of a signal, meanwhile, nonlinearly preserve the low-frequency components of the signal, we can adapt suitable fractional differential orders to restore their components. In particular, different differential orders can be used in an image at the same time. In order to obtain the restored image automatically, we choose the fractional differential orders by the value of gradient modulus of the image and use the discrete Fourier transform to implement the numerical algorithm. We also provide an iterative scheme in the frequency domain. Experimental results are reported to demonstrate that the visual effects, the combined image similarity index and the peak signal to noise ratio of restored images by using the proposed method are very good, and are competitive with the other testing methods.     

Restoration method of skin scattering blurred vein image for finger vein recognition

In general, the vein pattern in a finger vein image is not distinctive owing to light scattering through the skin layer, which makes detection of the finger vein region difficult. To solve this problem, a new finger vein image restoration method is proposed. Experimental results show that the equal error rate of finger vein recognition with the proposed restoration method is 0.76% and that without it is 1.35%.     

BCI Competition 2003--Data sets Ib and IIb: feature extraction from event-related brain potentials with the continuous wavelet transform and the t-value scalogram

The t-CWT, a novel method for feature extraction from biological signals, is introduced. It is based on the continuous wavelet transform (CWT) and Student's t-statistic. Applied to event-related brain potential (ERP) data in brain-computer interface (BCI) paradigms, the method provides fully automated detection and quantification of the ERP components that best discriminate between two samples of EEG signals and are, therefore, particularly suitable for classification of single-trial ERPs. A simple and fast CWT computation algorithm is proposed for the transformation of large data sets and single trials. The method was validated in the BCI Competition 2003, where it was a winner (provided best classification) on two data sets acquired in two different BCI paradigms, P300 speller and slow cortical potential (SCP) self-regulation. These results are presented here.     

Admittance matrix formulation of waveguide discontinuity problems:computer-aided design of branch guide directional couplers

A computational scheme is proposed that can be applied to the analysis of cascaded waveguide discontinuities of alternating boundary-enlargement and boundary-reduction type. Based on the mode-matching technique, the proposed procedure makes use of the admittance matrix characterization of waveguide stubs. With respect to the conventional S-matrix formulation, it leads to a notable reduction of the computational effort, particularly for lossless structures. At the same time, the criterion for avoiding relative convergence problems can be satisfied. The procedure has been used to set up a very accurate and efficiency computer-aided design tool of branch guide couplers (BGCs). These are key elements of beam-forming networks for multicontoured beam satellite antennas and have to be designed with very high accuracy so as to eliminate the necessity for tuning the components realized. Design accuracies better than 0.1 dB in Ka-band are demonstrated by experimental results     

Multispectral image restoration with multisensors

A procedure is advanced to restore a single color image, which has been degraded by a linear shift-invariant blur in the presence of additive stationary noise. Four sensors are needed, followed by the application of the RGB-to-YIQ transformation. Subsequently, one three-dimensional (3D) Wiener filter on a sequence of two luminance component images and two two-dimensional (2D) Wiener filters on each of the two chrominance component images are needed. For the procedure to be successful, the imposition of a strongly coprime condition on the wavenumber response of two distinct sensor blur functions is necessary. The resulting well-conditioned problem is shown to provide improved restoration over the decorrelated component and the independent channel restoration methods, each of which uses one sensor for each of the three primary color components     

Modelling LED lamps in SPICE with thermal phenomena taken into account

In this paper the improved version of the electrothermal model of LED lamps dedicated for SPICE software is proposed. The electrothermal models of components of such lamps: the LED module and the power supply are described. The elaborated model of the lamp makes it possible to calculate optical and electrical quantities characterising properties of the lamp and additionally, the internal temperatures of components of such lamps. The procedure of model parameters estimation is worked out, too. The correctness of the elaborated model was verified experimentally for the selected types of LED lamps. A good agreement between the results of calculations and measurements was obtained.     

ERP系统IAM的网络安全设计

ERP系统的安全应用一直是企业面临的信息安全问题,为了保障ERP应用与信息访问的安全性,我们为ERP系统搭建了一套IAM（Identity and Access Management）网络安全方案.该方案为ERP应用提供了可靠、高效的指纹认证以及安全可靠的包过滤防火墙模块、实时的数据库进程监控模块;从而确保ERP系统信息的安全可靠.本文叙述了IAM系统;分析了IAM系统内部与ERP系统的交互过程;然后详述了基于Windows API包过滤技术的防火墙模块的设计以及相关的其它网络安全设计,使系统可根据IAM身份验证信息进行动态过滤的目的,弥补了一般防火墙规则难以与应用软件灵活互动的不足,为企业应用的信息安全访问提供了可靠的保障.     

ERP与ISO9000质量管理体系

本文介绍了ERP的起源和一些基本概念,从管理思想角度入手,比较了ERP和ISO9000质量管理体系的异同,分析了两者的联系以及结合的可能性.认为以ISO9000的理论为基础,结合ERP生产管理思想,再利用ERP软件这一先进的工具,可为企业创造更高的效益.     

A statistical model of FM-TV spectra for satellite interference and distortion prediction

The requirement for a model of FM-TV spectra in the planning procedure of satellite communication systems is introduced. Based on long-term measurements of live TV channels, statistical properties of video spectra are examined and probability distributions for the luminance and chrominance components are proposed. The spectrum of the frequency-modulated signal is then derived, and signal distortion due to bandlimiting is calculated. Adjacent and cochannel interference effects are also investigated, with example cases illustrating influences of subcarrier loading and energy dispersion. The proposed model, which describes FM-TV spectra in terms of random variables, makes it possible to examine relative effects of system parameters, and will, therefore, be of benefit in the planning of new satellite services.     

交替使用小波去噪和全变差正则化的盲图像恢复算法

盲图像恢复就是在点扩散函数未知情况下从降质观测图像恢复出原图像.该文提出了一种交替使用小波去噪和全变差正则化的盲图像恢复算法.观测模型首先被分解成两个相互关联的子模型,这种分解转化盲恢复问题成为图像去噪和图像恢复两个问题,可以交替采用图像去噪和图像恢复算法求解.模糊辨识阶段,使用全变差正则化算法估计点扩散函数;图像恢复阶段,使用小波去噪和全变差正则化相结合的算法恢复图像.实验结果和与其它方法的比较表明该文算法能够获得更好的恢复效果.