动背景下帧差分法与边缘信息融合的目标检测算法

针对动背景下运动目标的检测问题,文中提出了改进的三步搜索算法有效地提高灰度投影法检测序列帧间运动矢量搜索速度,同时保持了运动矢量的搜索精度.首先通过帧间运动矢量补偿将连续三帧图像的相同背景稳定在同一幅图像的相同位置上,其次对连续的三帧图像进行边缘信息提取,并对三帧连续的边缘图像进行差分法运算,最后结合数学形态学的闭运算...     

自适应六边形-菱形运动估计算法及其在H.264中应用

运动估计是视频图像编码中运算量很大的部分,也是影响系统实时性能的瓶颈。为了减少图像编码的运算量,文章介绍和分析了用于视频编码标准H.264的基于六边形的搜索算法(HS),在此基础上根据H.264多模式的运动估计提出自适应六边形-菱形整像素算法,它体现了粗定位和准确定位的并行处理思想,仿真结果表明在获得与HS快速算法相当的图像质量和信噪比的情况下,可提高H.264视频编码的速度和效率。     

A pre-processing based optimized edge weighting method for colour constancy

An improvement in the existing weighted grey-edge (GE) framework for colour constancy is proposed. The acquired images are denoised by vector filtering and then, a two-step colour correction process is performed. In the first step, the GE method is used for estimating the global illuminant and perform the initial level of colour correction. The computed illuminant as well as the initial corrected image are used in the second step, which employs the weighted GE method to iteratively compute the final illuminant for obtaining the final colour corrected image. One hundred sixty-five standard test images from a publicly available colour constancy dataset were used to study the efficacy of the proposed algorithm. The results obtained indicate a significant improvement in the colour correction process as compared to the state-of-the-art colour constancy methods. The proposed algorithm reduced the mean angular error by approximately 67.85% compared to the existing weighted GE method.     

Preprocessing for static and dynamic facility layout problems

Most facility layout problems have departments with unequal areas and have significant rearrangement costs. This paper describes a model and improved algorithm which simultaneously handles these parameters. An existing algorithm solves the dynamic facilities layout problem while permitting the departments to have unequal areas. One part of the algorithm solves a mixed integer programming problem to find the desired block diagram layout. This large, complex problem could only be solved optimally for small problems. Therefore a preprocessing method was developed to prespecify certain obvious department pair orientations, which had previously required binary variables. The method uses estimated location, department sizes, and flow costs to determine the probable variable values. Then, a revised branch and bound strategy solves for the less obvious department pair orientations. Test results show a significant cost reduction on a variety of previously published problems, and feasible solutions to previously unsolved problems. The algorithm found a layout solution to the standard . CRAFT problem which has 10 5% lower costs than the previously best published layout.     

Fitness adaptive deer hunting-based region growing and recurrent neural network for melanoma skin cancer detection

This proposal aims to enhance the accuracy of a dermoscopic skin cancer diagnosis with the aid of novel deep learning architecture. The proposed skin cancer detection model involves four main steps: (a) preprocessing, (b) segmentation, (c) feature extraction, and (d) classification. The dermoscopic images initially subjected to a preprocessing step that includes image enhancement and hair removal. After preprocessing, the segmentation of lesion is deployed by an optimized region growing algorithm. In the feature extraction phase, local features, color morphology features, and morphological transformation-based features are extracted. Moreover, the classification phase uses a modified deep learning algorithm by merging the optimization concept into recurrent neural network (RNN). As the main contribution, the region growing and RNN improved by the modified deer hunting optimization algorithm (DHOA) termed as Fitness Adaptive DHOA (FA-DHOA). Finally, the analysis has been performed to verify the effectiveness of the proposed method.     

VLSI design for MPEG-4 shape coding using a contour-based binary motion estimation algorithm

An efficient architecture with the fast algorithm for MPEG-4 shape coding is proposed. The authors apply the fast shape coding algorithm, with contour-based binary motion estimation (CBBME), which is based on the properties of a boundary mask. By using the block-matching motion estimation and the extended approach on centre-biased motion vector distribution with shrinking of the search range, a large number of search points in BME can be skipped. Based on this algorithm, a dedicated architecture design using the proposed CBBME algorithm is developed. With certain optimisation and design considerations, the memory access and processing cycles can be reduced. The average number of clock cycles for the processing of one binary alpha block is only 1708, which is only 56% of the previous design. In addition, a prototyping chip for shape coding is implemented and verified. The die area is 2.4 x 2.4 mm² with TSMC 0.18 μm CMOS technology and the maximum clock frequency is 53 MHz.     

Optical flow-based motion compensation algorithm for very low-bit-rate video coding

In this article, we propose an efficient compression algorithm for very low-bit-rate video applications. The algorithm is based on (a) an optical-flow motion estimation to achieve more accurate motion prediction fields; (b) discrete cosine transformation (DCT) coding of the motion vectors from the optical-flow estimation to reduce the motion overheads; and (c) an adaptive threshold technique to match optical flow motion prediction and minimize the residual errors. Unlike the classic block-matching based DCT video coding schemes in MPEG-1/2 and H.261/3, the proposed algorithm uses optical flow for motion compensation and the DCT is applied to the optical flow field instead of predictive errors. Thresholding techniques are used to treat different regions to complement optical flow technique and to efficiently code residual data. While maintaining a comparable peak signal-to-noise ratio (PSNR) and computational complexity with that of ITU-T H.263/TMN5, the reconstructed video frames of the proposed coder are free of annoying blocking artifacts, and hence visually much more pleasant. The computer simulation are conducted to show the feasibility and effectiveness of the algorithm. Results at 11 kbps are presented which can be used for videophone applications in the existing public switched telephone network (PSTN). © 1998 John Wiley & Sons, Inc. Int J Imaging Syst Technol, 9, 230–237, 1998     

Scalable and systolic Montgomery multiplier over GF(2m) generated by trinomials

A Montgomery's algorithm in GF(2^m) based on the Hankel matrix-vector representation is proposed. The hardware architecture obtained from this algorithm indicates low-complexity bit-parallel systolic multipliers with irreducible trinomials. The results reveal that the proposed multiplier saves approximately 36% of space complexity as compared to an existing systolic Montgomery multiplier for trinomials. A scalable and systolic Montgomery multiplier is also developed by applying the block-Hankel matrix-vector representation. The proposed scalable systolic architecture is demonstrated to have significantly less time-area product complexity than existing digit-serial systolic architectures. Furthermore, the proposed architectures have regularity, modularity and local interconnectability, making the.m highly appropriate for VLSI implementation.     

Adaptive Order Cross–Square–Hexagonal search and fuzzy tangential-weighted trade-off for H.264 in motion estimation

In recent years, various algorithms have been proposed to attain low computational complexity in motion estimation of the image sequence coding based on block matching. This paper presents an Adaptive Order Cross–Square–Hexagon (AOCSH) search algorithm, which employs a smaller cross-shaped pattern before the first step of a square pattern and replaces the square-shaped pattern with the hexagon search patterns in subsequent steps. The proposed search patterns aid in finding the best matching block, without much consideration of the vast number of search points. Here, fuzzy tangent-weighted function is also proposed to evaluate the matching points using the rate and the distortion parameters. The proposed methods are effectively applied to the block estimation process to handle the objectives of visual quality and distortion. The performance of the proposed AOCSH approach is compared to the existing methods, such as AOSH, H.264 and elastic models, using the structural similarity index (SSIM) and the peak signal to noise ratio (PSNR). From the analysis, it can be seen that the proposed approach attains the maximum SSIM of 0.99 and maximum PSNR of 40. 92 dB with reduced computation time of 3.28 s.     

2-D companding for noise reduction in strain imaging

Companding is a signal preprocessing technique for improving the precision of correlation-based time delay measurements. In strain imaging, companding is applied to warp 2-D or 3-D ultrasonic echo fields to improve coherence between data acquired before and after compression. It minimizes decorrelation errors, which are the dominant source of strain image noise. The word refers to a spatially variable signal scaling that compresses and expands waveforms acquired in an ultrasonic scan plane or volume. Temporal stretching by the applied strain is a single-scale (global), 1-D companding process that has been used successfully to reduce strain noise. This paper describes a two-scale (global and local), 2-D companding technique that is based on a sum-absolute-difference (SAD) algorithm for blood velocity estimation. Several experiments are presented that demonstrate improvements in target visibility for strain imaging. The results show that, if tissue motion can be confined to the scan plane of a linear array transducer, displacement variance can be reduced two orders of magnitude using 2-D local companding relative to temporal stretching.     

Reused sad for partial search area in efficient three‐step search algorithm

Abstract

In real‐time applications, three‐step search (TSS) is always preferred because it has a regular search pattern. However, it may lose its performance in coding video sequences with small motion. To overcome this drawback, some fast search algorithms are proposed, for example, new three‐step search (NTSS) and efficient three step search (ETSS). In this paper, a more effective fast search algorithm called region‐split three‐step search (RSTSS) is proposed. In addition to the feature of a regular search pattern, the RSTSS splits the search region into four sub‐regions and enters only one of the sub‐regions to search for the best motion vector. The main idea used in the RSTSS is to reuse the sum of absolute difference (SAD) values of the 9 points on a 9 ×9 grid. Experimental results show that the RSTSS performs better than the ETSS in terms of the number of checking points. It can reduce the number of checking points nearly 19% on average and sacrifices only a little mean squared error. Most of all, the RSTSS retains a regular searching pattern that is suitable for hardware implementation.     

An ant colony optimisation algorithm for scheduling in agile manufacturing

Producing customised products in a short time at low cost is one of the goals of agile manufacturing. To achieve this goal an assembly-driven differentiation strategy has been proposed in the agile manufacturing literature. In this paper, we address a manufacturing system that applies the assembly-driven differentiation strategy. The system consists of machining and assembly stages, where there is a single machine at the machining stage and multiple identical assembly stations at the assembly stage. An ant colony optimisation (ACO) algorithm is developed for solving the scheduling problem of determining the sequence of parts to be produced in the system so as to minimise the maximum completion time (or makespan). The ACO algorithm uses a new dispatching rule as the heuristic desirability and variable neighbourhood search as the local search to make it more efficient and effective. To evaluate the performance of heuristic algorithms, a branch-and-bound procedure is proposed for deriving the optimal solution to the problem. Computational results show that the proposed ACO algorithm is superior to the existing algorithm, not only improving the performance but also decreasing the computation time.     

一种用于AVS视频编码的块运动估计算法

通过对现有的视频图像编码中的帧间预测技术所用的运动估计算法的分析,提出了一种适用于AVS视频编码标准的快速而有效的块运动估计算法,该算法采用5个检测点的大菱形和9个检测点的小田字形双模板结构,通过调用大菱形模板和小田字形模板进行块运动匹配搜索,随着搜索的进行,大菱形模板可以被循环调用,但约定小田字形模板仅被调用一次.通过与全搜索算法和菱形搜索算法比较,这种新的块运动估计算法在保证编码性能几乎不变的情况下,编码复杂性能够得到有效的降低.     

Proposal for a multi-material design procedure

This paper describes a proposal for a multi-material design procedure. First, the context of the study and the requirements of the multi-material must be clearly defined in order to specify the parameters that the designer must select or optimise in order to produce the design: the components and their volume fraction, the architecture and morphology at different scales, etc. The general design procedure proposed here starts with the reasons why the designer has turned to multi-materials, from which a multi-material concept with fixed parameters can be defined. In this first stage the design problem can be made less complex by reducing the number of unknown parameters and guiding the designer towards the appropriate selection or optimisation tools: (i) subdivision of requirements, guided by applying statistical analysis tools to the materials database to search for appropriate multi-material components, (ii) tools to filter the materials database and search for multi-material components and their volume fraction, (iii) optimisation tools to search for the appropriate architecture when components are known or to search for architecture and components simultaneously. The paper demonstrates how these tools can be applied to different design concepts.     

Novel fast block motion estimation using diamond‐arc‐hexagon search patterns

Abstract

This work presents a novel block motion estimation (ME) approach, diamond‐arc‐hexagon search (DAHS), which uses diamond, arc, and hexagon search patterns to accomplish the fast searching process. According to the characteristic of the center‐based motion vector distribution for the real‐world video sequence, DAHS employs a small diamond pattern extended hexagon search to refine the central area search. Furthermore for estimation in large motion situations, the strategy of the large diamond‐to‐arc search can preserve good performance. Experimental results indicate that DAHS is suitable for both (quasi‐) stationary and large motion searches. DAHS outperforms the efficient three‐step (E3SS) and hexagon‐based search (HEXBS) in prediction quality, and improves the searching speed about 9% compared to E3SS. The proposed algorithm was tested using several sequences and delivered excellent performance in search speed and prediction of video quality. The DAHS can be applied to real‐time video processes, such as H.264/MPEG‐4 advanced video coding (AVC) and scalable video coding (SVC).     

On optimum life-testing plans under Type-II progressive censoring scheme using variable neighborhood search algorithm

In determination of optimum Type-II progressive censoring scheme, the experimenter needs to carry out an exhaustive search within the set of all admissible censoring schemes. The existing recommendations are only applicable for small sample sizes. The implementation of exhaustive search techniques for large sample sizes is not feasible in practice. In this article, a meta-heuristic algorithm based on variable neighborhood search approach is proposed for large sample sizes. It is found that the algorithm gives exactly the same solution for small sample sizes as the solution obtained in an exhaustive search; however, for large sample sizes, it gives near-optimum solution. We have proposed a cost function-based optimum criterion, which is scale invariant for location-scale and log-location-scale families of distribution. A sensitivity analysis is also considered to study the effect of misspecification of parameter values or cost coefficients on the optimum solution.     

Search for minimal paths in modified networks

The problem of searching for all minimal paths (MPs) in a network obtained by modifying the original network, e.g. for network expansion or reinforcement, is discussed and solved in this study. The existing best-known method to solve this problem was a straightforward approach. It needed extensive comparison and verification, and failed to solve some special but important cases. Therefore, a more efficient, intuitive and generalized method to search for all MPs without an extensive research procedure is proposed. In this presentation, first we develop an intuitive algorithm based upon the reformation of all MPs in the original network to search for all MPs in a modified network. Next, the computational complexity of the proposed algorithm is analyzed and compared with the existing methods. Finally, examples illustrate how all MPs are generated in a modified network based upon the reformation of all of the MPs in the corresponding original network.     

基于独立分量分析的波束空间波达方向估计算法

波束空间变换是波达方向估计算法中重要的预处理方法,该方法适合大阵列、小信号源数的场合,可以有效降低运算量。但是目前存在的波束空间类DOA估计算法大多需要预知信号的大致来向,同时对阵型有要求。为了解决上述问题,提出一种基于独立分量分析的波束空间DOA估计算法,使用独立分量分析方法获得波束形成变换矩阵。该算法对阵型无要求、无需知道信号来向并且具备较强的角度分辨能力。仿真实验验证了有效性。     

A new fast block matching algorithm based on complexity‐distortion optimization

Most fast block matching algorithms ignore the efficiency in motion compensation within each checking step. In order to achieve better‐compensated performance, the limited computational complexity should be allocated more carefully into each block. It means that the fast block matching algorithm can be viewed as a kind of rate‐distortion optimization problem. The complexity‐distortion optimal fast block matching algorithm should find the maximized quality of the compensated image under a target computational complexity. In order to approach the optimal complexity‐distortion solution, some strategies are developed. For example, a domination‐based motion vector prediction technique is developed to set the initial motion vector for each block. A predictive complexity‐distortion benefit list is established to predict the compensated benefit for each block. Also, a three‐level pattern searching is employed to check the candidate motion vector. Experimental results show that our proposed algorithm outperforms significantly the three‐step search. For example, in “Salesman,” the average checkpoints for one block is 33 by using the three‐step search. The average checkpoint is 1.75 by using our proposal algorithm under the same average PSNR condition. © 2002 Wiley Periodicals, Inc. Int J Imaging Syst Technol 12, 63–67, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ima.10012     

Superelement method for transient dynamic analysis of structural systems

A superelement algorithm for the transient dynamic analysis of structural systems is presented. The method represents a generalization of existing static and dynamic superelement (substructure) algorithms. Natural frequencies and modal shapes of a fixed boundary substructure are used to obtain equations of motion of a superelement. An implicit time-stepping algorithm is presented for the numerical solution of a resulting superelement system of equations of motion. Numerical examples are given to illustrate the presented approach. The method is believed to be effective for large-scale problems of structural analysis.