Graphical Search for Images by <Emphasis Type="Italic">PictureFinder</Emphasis>

The text searching paradigm still prevails even when users are looking for image data for example in the Internet. Searching for images mostly means searching on basis of annotations that have been made manually. When annotations are left empty, which is usually the case, searches on image file names are performed. This may lead to surprising retrieval results. The graphical search paradigm, searching image data by querying graphically, either with an image or with a sketch, currently seems not to be the preferred method partly because of the complexity in designing the query.In this paper we present our PictureFinder system, which currently supports “full image retrieval” in analogy to full text retrieval. PictureFinder allows graphical queries for the image the user has in his mind by sketching colored and/or textured regions or by whole images (query by example). By adjusting the search tolerances for each region and image feature (i.e. hue, saturation, lightness, texture pattern and coverage) the user can tune his query either to find images matching his sketch or images which differing from the specified colors and/or textures to a certain degree. To compare colors we propose a color distance measure that takes into account the fact that different colors spread differently in the color space, and which take into account that the position of a region in an image may be important.Furthermore, we show our query by example approach. Based on the example image chosen by the user, a graphical query is generated automatically and presented to the user. One major advantage of this approach is the possibility to change and adjust a query by example in the same way as a query which was sketched by the user. By deleting unimportant regions and by adjusting the tolerances of the remaining regions the user may focus on image details which are important to him.     

Frequency analysis of a bumblebee (<Emphasis Type="Italic">Bombus impatiens</Emphasis>) wingbeat

The wingbeat of an insect relates directly to energy consumption, is a strong indicator of its rate of metabolism and physical structure, and inversely relates to the length of its wing and to the mass of its body. It is also a principal component in understanding the aerodynamic properties of its flight. In this paper, we introduce a method based on the use of high-speed cameras and computer vision techniques to analyze a bumblebee (Bombus impatiens) wingbeat. We start capturing images with a virtual stereo system when a bumblebee crosses two intersecting laser beams. Then, we detect moving objects using background subtraction. Next, via Fourier analysis of the observed optical flow contraction/expansion, and marginalization of prior knowledge, we estimate the wingbeat frequency. Finally, the information from the two virtual cameras is fused using a robust state estimation. Our system is well prepared to handle occlusions; it works with untethered insects; and it does not require the synchronization of a multi-camera system.     

The Number of Independent Kruppa Constraints from <Emphasis Type="Italic">N</Emphasis> Images

It is well known that without any priori knowledge on the scene, camera motion and camera intrinsic parameters, the only constraint between a pair of images is the so-called epipolar constraint, or equivalently its fundamental matrix. For each fundamental matrix, at most two independent constraints on the cameras＇ intrinsic parameters are available via the Kruppa equations. Given N images, N（N- 1）/2 fundamental matrices appear, and N（N- 1） Kruppa constraints are available. However, to our knowledge, a formal proof of how many independent Kruppa constraints exist out of these N（N - 1） ones is unavailable in the literature. In this paper, we prove that given N images captured by a pinhole camera with varying parameters and under general motion, the number of independent Kruppa constraints is （5N - 9） （N 〉 2）, and it is less than that of independent constraints from the absolute quadric by only one. This one-constraint-less property of the Kruppa equations is their inherent deficiency and is independent of camera motion. This deficiency is due to their failure of automatic enforcement of the rank-three-ness on the absolute quadric.     

Robust/H∞ filtering for nonlinear systems

A robust (or H_∞) approach to filtering for nonlinear systems is considered. A bound on the estimate error as a function of the disturbance energy is obtained. The corresponding dynamic programming equation is a first-order PDE. This has computational ramifications. The case where the measurements are discrete time is considered also. A numerical method is discussed.     

A snake for model-based segmentation of biomedical images

In this work we present a snake based approach for the segmentation of images of computerized tomography (CT) scans. We introduce a new term for the internal energy and another one for external energy which solve common problems associated with classical snakes in this type of images. A simplified minimizing method is also presented.     

M<Emphasis Type="SmallCaps">osaic</Emphasis>: A Scalable Coherence Protocol

The coherence protocol presented in this work, denoted Mosaic, introduces a new approach to face the challenges of complex multilevel cache hierarchies in future many-core systems. The essential aspect of the proposal is to eliminate the condition of inclusiveness through the different levels of the memory hierarchy while maintaining the complexity of the protocol limited. Cost reduction decisions taken to reduce this complexity may introduce artificial inefficiencies in the on-chip cache hierarchy, especially when the number of cores and private cache size is large. Our approach trades area and complexity for on-chip bandwidth, employing an integrated broadcast mechanism in a directory structure. In energy terms, the protocol scales like a conventional directory coherence protocol, but relaxes the shared information inclusiveness. This allows the performance implications of directory size and associativity reduction to be overcome. As it is even simpler than a conventional directory, the results of our evaluation show that the approach is quite insensitive, in terms of performance and energy expenditure, to the size and associativity of the directory.     

Supervised vessel delineation in retinal fundus images with the automatic selection of <Emphasis Type="Italic">B</Emphasis>-COSFIRE filters

The inspection of retinal fundus images allows medical doctors to diagnose various pathologies. Computer-aided diagnosis systems can be used to assist in this process. As a first step, such systems delineate the vessel tree from the background. We propose a method for the delineation of blood vessels in retinal images that is effective for vessels of different thickness. In the proposed method, we employ a set of B-COSFIRE filters selective for vessels and vessel-endings. Such a set is determined in an automatic selection process and can adapt to different applications. We compare the performance of different selection methods based upon machine learning and information theory. The results that we achieve by performing experiments on two public benchmark data sets, namely DRIVE and STARE, demonstrate the effectiveness of the proposed approach.     

The N-soliton solution and localized wave interaction solutions of the (2+1)-dimensional generalized Hirota-Satsuma-Ito equation

In this paper, the $N$-soliton solution is constructed for the ($2+1$)-dimensional generalized Hirota–Satsuma–Ito equation, from which some localized waves such as line solitons, lumps, periodic solitons and their interactions are obtained by choosing special parameters. Especially, by selecting appropriate parameters on the multi-soliton solutions, the two soliton can reduce to a periodic soliton or a lump soliton, the three soliton can reduce to the elastic interaction solution between a line soliton and a periodic soliton or the elastic interaction between a line soliton and a lump soliton, while the four soliton can reduce to elastic interaction solutions among two line solitons and a periodic soliton or the elastic interaction ones between two periodic solitons. Detailed behaviours of such solutions are illustrated analytically and graphically by analysing the influence of parameters. Finally, an inelastic interaction solution between a lump soliton and a line soliton is constructed via the ansatz method, and the relevant interaction and propagation characteristics are discussed graphically. The results obtained in this paper may be helpful for understanding the interaction phenomena of localized nonlinear waves in two-dimensional nonlinear wave equations.     

基于小波模糊聚类的均质纹理和非均质纹理图象检索

基于内容的图象检索是近年来的研究热点 ,为此提出了一种自动区分均质纹理和非均质纹理图象 ,并对这两类图象分别进行检索的算法 .算法首先从图象离散小波变换的低频子带提取一定的颜色和纹理特征用于模糊聚类 ,将图象的低频子带分割为一定的区域 ;然后根据分割的结果将图象自动语义分类为均质纹理或者非均质纹理图象 ;最后对均质纹理和非均质纹理图象分别提取不同的特征矢量 ,并按照一定的相似度准则检索图象 .实验结果表明 ,该算法具有良好的均质纹理和非均质纹理图象分类和检索性能 .     

An iteration method for solving the linear system Ax=b

In this paper, based on a convergence splitting of the matrix $A$, we present an inner–outer iteration method for solving the linear system $Ax=b$. We analyze the overall convergence of this method without any other restriction on its parameters. Moreover, we give the accelerated inner–outer iteration method, and discuss how to apply the inner–outer iterations as a preconditioner for the Krylov subspace methods. The inner–outer iteration method can also be used for the solution of $AXB=C$. Finally, several numerical examples are given to validate the performance of our proposed algorithms.     

A variable exponent nonlocal p(x)-Laplacian equation for image restoration

In this paper, we focus on the mathematical and numerical study of a variable exponent nonlocal $p\left(X\right)$-Laplacian equation for image denoising. Based on the Semigroup Theory, we prove the existence and uniqueness of solution for the proposed model. To illustrate the efficiency and effectiveness of our model, we provide the denoising experimental results as well we compare it with some existing models in the literature.     

基于LGDF模型的医学图像分割及有偏场校正

为实现对灰度不均匀医学图像分割的同时进行有偏场估计并校正,改进了基于局部高斯分布拟合(Local Gaussian Distribution Fitting,LGDF)能量的活动轮廓模型。通过分析图像有偏场模型的局部特性,将有偏场乘性因子引入图像局部灰度均值的表达中,从而使有偏场乘性因子成为新的能量函数的变量。能量函数的迭代最小化既实现了目标组织分割,又有效估计了有偏场。合成图像和真实医学图像实验表明该方法比现有多种方法分割性能更好,且利用估计的有偏场校正后的图像具有更好的视觉效果。     

SQR: a simple quantum representation of infrared images

A simple quantum representation (SQR) of infrared images is proposed based on the characteristic that infrared images reflect infrared radiation energy of objects. The proposed SQR model is inspired from the Qubit Lattice representation for color images. Instead of the angle parameter of a qubit to store a color as in Qubit Lattice representation, probability of projection measurement is used to store the radiation energy value of each pixel for the first time in this model. Since the relationship between radiation energy values and probability values can be quantified for the limited radiation energy values, it makes the proposed model more clear. In the process of image preparation, only simple quantum gates are used, and the performance comparison with the latest flexible representation of quantum images reveals that SQR can achieve a quadratic speedup in quantum image preparation. Meanwhile, quantum infrared image operations can be performed conveniently based on SQR, including both the global operations and local operations. This paper provides a basic way to express infrared images in quantum computer.     

CPMC-Lab: A Matlab package for Constrained Path Monte Carlo calculations

We describe CPMC-Lab, a Matlab program for the constrained-path and phaseless auxiliary-field Monte Carlo methods. These methods have allowed applications ranging from the study of strongly correlated models, such as the Hubbard model, to ab initio calculations in molecules and solids. The present package implements the full ground-state constrained-path Monte Carlo (CPMC) method in Matlab with a graphical interface, using the Hubbard model as an example. The package can perform calculations in finite supercells in any dimensions, under periodic or twist boundary conditions. Importance sampling and all other algorithmic details of a total energy calculation are included and illustrated. This open-source tool allows users to experiment with various model and run parameters and visualize the results. It provides a direct and interactive environment to learn the method and study the code with minimal overhead for setup. Furthermore, the package can be easily generalized for auxiliary-field quantum Monte Carlo (AFQMC) calculations in many other models for correlated electron systems, and can serve as a template for developing a production code for AFQMC total energy calculations in real materials. Several illustrative studies are carried out in one- and two-dimensional lattices on total energy, kinetic energy, potential energy, and charge- and spin-gaps.     

Image Stabilization for In Vivo Microscopy by High-Speed Visual Feedback Control

This paper presents image stabilization for microscopy using horizontal visual feedback control of the objective lens through a five-bar linkage and piezoelectric actuators, and its application to in vivo imaging. Even very small in vivo motion due to heartbeat and breathing makes microscopic observation difficult by blurring the microscope image or impossible by sending a region of interest out of view. In order to remove those unwanted effects of the motion, we have introduced motion-canceling robotic technologies into microscopy. Our image stabilization system through motion-canceling provides users with stabilized image sequences with respect to trembling of in vivo subjects. The developed image stabilization system, in term of robotics, corresponds to a visual feedback control system that consists of a robotic mechanism and a high-speed vision. A high-speed camera installed in the microscope detects the motion of the in vivo subject having topically applied fiducials. To virtually cancel this motion, we move the objective lens, synchronizing the motions of the subject and the lens to remove the relative motion between the two. As a result, we observe motion-free images to m. This technology is one of the very demanding technologies in biological research for in vivo observation with high resolution. In this paper, we verify the effectiveness of the developed system through in vivo experiments.     

Equivalent a posteriori error estimates for elliptic optimal control problems with L1-control cost

An elliptic optimal control problem involving the $L^1$ norm of the control in the cost functional is considered in this paper. We use the full discretization and the variational discretization to approximate the control problem and the efficient and reliable a posteriori error estimates are obtained for the two cases. For the variational discretization, we also analyze the convergence of adaptive finite element methods. In the end, some examples are provided to validate our analysis.     

Order statistics and probabilistic robust control

Order statistics theory is applied in this paper to probabilistic robust control theory to compute the minimum sample size needed to come up with a reliable estimate of an uncertain quantity under continuity assumption of the related probability distribution. Also, the concept of distribution-free tolerance intervals is applied to estimate the range of an uncertain quantity and extract the information about its distribution. To overcome the limitations imposed by the continuity assumption in the existing order statistics theory, we have derived a cumulative distribution function of the order statistics without the continuity assumption and developed an inequality showing that this distribution has an upper bound which equals to the corresponding distribution when the continuity assumption is satisfied. By applying this inequality, we investigate the minimum computational effort needed to come up with an reliable estimate for the upper bound (or the lower bound) and the range of a quantity. We also give conditions, which are much weaker than the absolute continuity assumption, for the existence of such minimum sample size. Furthermore, the issue of making tradeoff between performance level and risk is addressed and a guideline for making this kind of tradeoff is established. This guideline can be applied in general without continuity assumption.