最新刊期
卷 11 ， 期 12 ， 2006
- 摘要：Topological relationship is one of the most important theoretical topics related to GIS modeling, and it plays a key role in many geo-technical fields such as spatial data modeling, spatial query, spatial analysis, spatial reasoning, and cartographic generalization. To motivate further research and applications of the theory, this paper reviews the formalisms and formal models of topological relations. First, the approaches that describe topological relations under certainty are briefly examined. Then the developing progress toward topological relations with uncertainties is explored in terms of research methodologies, including broad boundary approach, fuzzy set approach, random set approach, and rough set approach. Moreover, some applications of the theory in spatial query, spatial analysis and spatial reasoning, are basically introduced. Finally, several issues are highlighted for future investigations.关键词：geographic information system;topological relations;uncertainty;formalism3260|187|0更新时间：2024-05-07
- 摘要：The Gradient is important information which is frequently used in image processing, while there is hardly any accurate mathematics model to describe the relationship between image gradient and image module at present. Therefore, after analyzing the character of image gradient histogram, a mathematics model based on Gamma distribution is proposed, and then a solution to the model found on EM algorithm is presented. At last, accuracy and validity of the model are verified by an application example and result analysis.关键词：gradient field;mixed gamma distribution;EM algorithm;parameter estimation2912|231|0更新时间：2024-05-07
- 摘要：PSNR(peak signal noise ratio) is the common criterion used to assess the distortion of signal.But big error maybe generated with PSNR which does not involve the content of signal when used to assess image quality.SSIM(structural similarity) is used to evaluate the similarity between the source signal and the processed signal.SSIM is simple and well correlated with subject evaluation.This paper,PSNR and SSIM are combined to set up the image quality assessing model.Cluster analysis is used to make the samples data cluster into different kinds.Support Vector Machines Classifier is used to class any image into different kinds according to PSNR and SSIM.The quality of the image with different kinds is assessed with different strategy.The results from our test show the model output can reflect the image subjective quality effectively.关键词：cluster analysis;quality assessing;support vector machines;SSIM(structural similarity);PSNR(peak signal noise ratio)7605|339|0更新时间：2024-05-07
- 摘要：A novel approach for color image segmentation is studied,which is based on segmentation of subsets of bands using mathematical morphology followed by the fusion of the resulted segmentation "channels".For color images the band subsets are chosen as the RG,RB and GB pairs,whose 2D histograms are processed as projections of a 3D histogram.The segmentation in 2D color spaces is obtained using the watershed algorithm.The final color image segmentations are combined by a region splitting-merging process.CIE(L*a*b*) color space is employed to measure the color distance.The proposed approach results in improved performance and running time.关键词：color image segmentation;mathematical morphology;image fusion2901|235|0更新时间：2024-05-07
- 摘要：By means of self-organizing clustering,a new color-based image retrieval method is proposed in the paper.According to the colors' distributing information in the image,every pixel is assigned a weighing value and thus the initial number of clustering can be confirmed.Therefore,those weighed pixels are clustered and the dominant colors' statistical features are acquired.Based on the dominant colors spread in the image,the colors' moment features are extracted to present their special features simultaneously.Therefore,the whole image's content can be expressed from general statistic to partial distributing by these two kinds of features.The experiments verify the method mentioned above is more efficiently than those ways based on color histogram.关键词：content based image retrieval;color features;cluster;moments features3069|232|0更新时间：2024-05-07
- 摘要：Comparing with the traditional image retrieval based on features matching,the method based on the contents of high-level semantic in image has distinguished advance in accuracy,content-relativity and anti-interference.An effective image retrieval method should make fully use of the high-level semantics contents of images.Based on the deep researching on the low-level features' description of image's high-level semantics,in this paper a new model on image's semantic levels is presented,and the extraction and retrieval algorithm for every level of image's semantic is established.The experimental results show that the algorithms can make effective extraction on image's high-level semantic information,and they can be used as a model on novel and effective image retrieval systems.关键词：content based image retrieval;stratified semantic model;high-level semantic information in image;information extraction;image mining4141|252|0更新时间：2024-05-07
- 摘要：In order to realize automatic and fast analysis ofmicroscopic image, in this paper, the binarized image was first transformed to distance format. Fast grayscale reconstruction algorithm was then employed to reconstruct the transformed image. Finally Watershed algorithm was used to segment the result image. In thisway, the defectof the watershed algorithm that the watershed marker extracting often depends on prior knowledge of the image is avoid and the algorithm to be suitable for real clinic practice and the auto segmentation of conglutination cells is realized. At last the algorithm was programmed with C++ and was used to segment the real clinical fall off cell and pathology cell images. After being applied tomany different disease and different background cell image, result shows that the algorithm can pick up destination cells in a given image and automatically segment overlap cells accurately and rapidly under the condition of even illumination. For a given 768×576 image, the algorithm can finish the segmentation within 2 seconds in a AMD 1600+ CPU. And the segmentation result is certificated by director doctor. Thus it is feasible to apply the algorithm to the segmentation of clinical cell image.关键词：watershed;over-segmentation;grayscale reconstruction;overlapping cell image3675|262|0更新时间：2024-05-07
- 摘要：The singular value vector of face image is analyzed and its nature is revealed,i.e.,the singular values of face image are obtained by decomposing the face in the special basis space that is determined by the face image.Based on this result,the intrinsic reasons that singular value vector-based recognition methods have the low recognition accauracy are follows: singular value vectors of arbitrary two face images have not the equivalent basis space in general;there is no one-to-one correspondence between singular value vector and face image;singular value vectors are not separated.Finally,a novel face recognition method coined class estimated basis space method is presented.ORL,ORL-NWPU1 and ORL-NWPU2 database are used to test,and the experimental results show the correctness of analysis and the proposed method.关键词：singular value vector;face recognition3653|245|0更新时间：2024-05-07
- 摘要：In this paper,bionics is applied to non-photorealistic rendering(NPR).A NPR method based on ant colony algorithm(ACS) with equilibrium of distribution is proposed.In this method,rendering ant is defined as an agent with attributes of pheromone,mark,lifecycle and so on and with behaviors of single-walking,rendering marks,updating pheromone,jumping and dying.The algorithm can direct rendering ants to select the most optimal rendering trail and adjust their behaviors such as single-walking,rendering marks,jumping and dying by updating pheromone continually.The marks that all rendering ants lay on the trails are just the rendering result.Because rendering ants select trails purely according to the selected probability,the tracks will converge by degree-which will lead to local rendering.To avoid this phenomenon,information weight is brought in to dynamically adjust the equilibrium of selected probability.And this brings more natural rendering results.Experimental results show that this method can simulate the painting process effectively and can get pleasant rendering effects.关键词：non-photorealistic rendering;bionics;ant colony algorithm;equilibrium of distribution2828|220|0更新时间：2024-05-07
- 摘要：Spread Transform Dither Modulation(STDM) is a watermarking algorithm having good performance.In this algorithm,the Project-vector used for spread transform is an important factor that affects its performance.This paper studies on the project-vector of STDM.Random project vector,uniform project vector,parallel project vector,project vector chosen according frequency and project vector chosen according HVS are introduced,the robustness under different project vectors is compared and analyzed,the way of choosing project-vectors that makes the robustness of STDM best under different attacks is obtained.Further,in order to make full use of the HVS's characteristics,choosing project-vector combined with HVS is introduced,and the experiment results show that by using this method,the visual quality and robustness of the STDM algorithm can be improved further.3200|172|0更新时间：2024-05-07
- 摘要：Given lifter's video acquired with an ordinary camera in lateral view,the trajectory of the barbell's center can be tracked automatically through an improved template matching algorithm.Key technical parameters are computed by the position of barbell's center and a technique analysis report consisting of parameters and graphs is created.Experiments show that tracking and analysis results are exact and reliable.This system has been applied to the practical training in weight lifting,to help analysis and improve the lifter's technique.关键词：video;barbell;tracking;template matching;analysis3065|195|0更新时间：2024-05-07
- 摘要：Key-frame animation is the common mode for making 3D animation, and twecn-frame interpolation is the most important part. This paper presents a non-linear interpolation algorithm aiming at the non-skeleton 3D mesh mode. This algorithm is used to carry on auto-interpolation to key-frame posture and to form twccn-framc animation serial. This algorithm firstly calculates the affine transformation of each triangle of mesh mode in adjacent key-frame and then creates deformation gradient vector. The deformation gradient vector is regarded as deforming information of mesh mode which reveals the local correlation between mesh vertices in deformation. In the following, each affine transformation is decomposed to rotation component and stretch scale component. The latter is made linear interpolation, while the former is made non-linear interpolation using quaternion interpolation algorithm. By this strategy, the deformation gradient vector of tween-frame posture is composed, according to which the tween-frame mesh mode is calculated. This algorithm can make stable and vivid key-frame animation when there is great difference in posture between adjacent key-frame. This algorithm can reduce the number of key-frame and improve the efficiency of animation making.关键词：3D animation;key-frame;tweenframe;quaternion3444|238|0更新时间：2024-05-07
- 摘要：In this paper we present a method of view planning for automatically constructing the model of an unknown object from range images.The method computes the next best view in two steps.First,the exploration direction for the next view is determined via a Mass Vector Chain(MVC) based scheme.Then the accurate position of the next view is obtained by computing the boundary integral of the vectors fields.The position with the maximum integral value is selected as Next Best View(NBV).We also present a selftermination criterion for judging the completion condition in the measurement and reconstruction process.The termination condition is derived based on changes in the volume computed from two successive viewpoints.The experimental results show that the method is effective in practical implementation.关键词：viewpoint planning;3D modeling;next best view;mass vector chain;self-termination2777|190|0更新时间：2024-05-07
- 摘要：Disparity estimation is used to eliminate redundancy among different views in multi-view video coding in order to obtain high compression efficiency. In this paper, characteristics of image block are extracted by using fast Walsh transformation, and a new method for reference view selection in multi-view disparity estimation is presented, based on the characteristic vector of image block and its similarity measurement. Experimental resuhs show that the proposed method can reduce the computational complexity in multi-view video coding with almost the same quality of reconstructed images.关键词：multiview video;reference view;characteristic vector of image block;similarity determination;disparity estimation2528|210|0更新时间：2024-05-07
- 摘要：Microcalcifications are the primary radiological indicator of early breast cancers. A method for the automatic detection of microcalcifications in digital mammograms is presented in this paper. The algorithm based on top-hat morphologic operator is developed to restrain the background, then the features of single microcalcifications such as gray, texture, and contrast, etc. are extracted to detect the microcalcifications in mammograms. The proposed method is based on the Top-hat operator. Comparing to other approaches, this method can more efficiently detect weak microcaleifications in the high background, and the detected results are much close to the actual shapes of the calcifications.关键词：Top-hat;detection of calcifications;computer-aided diagnosis2852|199|0更新时间：2024-05-07
- 摘要：Firstly, tracking model of moving objects in images is established based on Bayesian theory. Secondly, image regional information is described by Gaussian distribution. At the same time, the tracking model is matched to region-based active contours through analyzing, and then this problem is converted into the minimizing of energy. Lastly, level set is used to solve the PDE equation, which can process topology naturally. The result shows that the proposed method not only could track multi-objects and approach to the objects contours, but also does well when the moving objects deforms topologically.关键词：active contours;moving objects tracking;level set2696|205|0更新时间：2024-05-07
- 摘要：To provide continuous 24-hour monitoring of surveillance video, and improve the situational awareness of security providers and decision makers, this paper designs the semiautonomous surveillance system to seamlessly track objects using a network of cooperating active sensors, and presents a visual 3D scene. A instance of lab is also given in the end.关键词：video network;cooperative perception;object detection;object tracking3222|250|0更新时间：2024-05-07
- 摘要：This paper proposes a kind of energy minimization based extended depth-of-field method, which uses a measure of contrast to compose source images. The innovation point is that it makes use of the spatial consistency afforded by the energy minimization via graph-cut to solve the problem of composite artifacts, and uses the max-flaw algorithm to solve the graph-cut problem. In the end of the paper, we present the result, and then compare it with the result of the algorithm without spatial consistency. The result shows that the method can produce more perfect effect within an acceptable execution time.关键词：extended depth-of-field;energy minimization;graph cut;max-flow/min-cut4874|197|0更新时间：2024-05-07
- 摘要：Cutting away part of a 3D outer surface to show some interior objects hidden beneath it can play an important role in visualization and virtual reality. Previous methods have mainly aimed at showing the interior objects, and the shape of the hole has been considerably less important. In this paper, we propose a novel approach to cutting a specific hole in a surface. The user first defines the required shape on the surface; the algorithm then superimposes the shape on the surface and implements the cutaway. Jittering problems associated with the boundary generated by the above steps are resolved and experimental results demonstrate the efficiency of the algorithm.关键词：cutaway;jittering problems;OBB-tree;projection4303|178|0更新时间：2024-05-07
- 摘要：Extensive experimental results show that p is still linear with the bit rate of a macroblock slice in H.264 via p-domain source modeling. The bit allocation of the proposed method is achived according to the percentage of bit count of each macroblock slice in the first RDO. Experimental results show that the proposed rate control algorithm can guarantee the same coding efficiency, achieve significantly smaller bit rate estimation error and be better matched to the target bit rate than JM8.4 rate control algorithm.2640|199|0更新时间：2024-05-07
- Postal code：100190
- Tel：010-58887035/58887030/58887418 Email：jig@aircas.ac.cn
- Technical support is provided by Beijing Founder electronics co., LTD 京ICP备05080539号-4
京公网安备11010802024621 - It is recommended to read the content of this site in Chrome&IE9+. Please switch to extreme mode in browser 360.
- Cookies We use cookies to help provide and enhance our service and tailor content. By continuing, you agree to the use of cookies.
0