最新刊期
卷 6 ， 期 3 ， 2001
- 摘要：With the development of digital technology,various kinds of color image processing devices have been more frequently used than ever and color has become even more accessible.The increased use of color has brought with it new challenges and problems.In order to meaningfully record and process color images and to reduce color error caused by color imaging devices,it is essential to understand the mechanisms and limitations of these devices.In this paper,we reviewed some of the most commonly used color image recording and reproduction systems in present day.The system mechanisms and mathematical models used for representing these systems are discussed.The main problems existing in characterization,calibration and designing processes are recapitulated and the techniques used to solve them are also mentioned.This paper also provides a succinct introduction of some relatively new color imaging techniques,as well as their limitations and potentials of future applications.A forecast of research trends is attempted as well.2513|414|0更新时间：2024-05-07
- 摘要：Watershed transformation is a powerful morphological operator for image segmentation.It is performed on the gradient of the image to be segmented.Each minimum of the gradient leads to a region in the resulting segmentation.However,conventional gradient operators generally produce many local minima. Produced by noise and quantization error. Experimental result, which are caused by noise or quantization error.Hence,watershed transformation with a conventional gradient operator usually results in over segmentation.To alleviate this problem,this paper presents a multiscale algorithm for computing morphological gradient images,with effective handling of both step and blurred edges.We also present an algorithm to eliminate the local minima produced by noise and quantization error. Experimental results demonstrate that the proposed algorithm can effectively enhance step and blurred edges and reduce the number of local minima.Watershed transformation with the proposed algorithm produces meaningful segmentations,even without a region merging step.The proposed algorithm can significantly reduce the computational load of watershed based image segmentation methods.2999|542|0更新时间：2024-05-07
- 关键词：Space liquid experiment;BP artifical neural network;Image data compression2717|449|0更新时间：2024-05-07
- 摘要：It is very difficult to match SAR(Synthetic Aperture Radar) and optical images because of the difference physical peculiarity. A new image matching approach based on analyzing the physical peculiarity of the two sensors has been proposed. This method applies morphological filtering algorithm to remove the speckle noise of SAR image and uses the edge's features of images to solve the matching problem and uses the technology of multiresolution gradational searching to reduce the complexity of computation. A new criterion that can search the real match position based on analyzing the experimental result is presented. It will be able to give a more accurate matching result. We validate the speckle noise filtering algorithm and the matching algorithm between the SAR image and Optical image by experiment. Experimental results show that the filtering effect is more excellent then traditional Frost algorithm, the matching algorithm have high precision and stability.关键词：SAR image;Optical image;Morphological filtering;Image matching;Multiresolution gradational searching;edge feature3226|417|0更新时间：2024-05-07
- 摘要：In this paper,the segmentation based on Markov Random Field (MRF) is discussed to fulfill the fast segmentation of complex remote sensing image. Using this method, the cotton estimation model and the extraction of cotton areas from satellite image are realized and remote sensing cotton estimation system is constructed. According to the characteristics of the remote sensing image,the image segmentation model based on MRF is established.The problem of image segmentation can be converted to the problem of symbolizing,and finally converted to the solution of Maximum A Posterior (MAP), if the method of MRF is used. For obtaining the solution of MAP, the algorithm of simulated annealing (SA) can find the global optimum,but it requires a large amount of computation. So sub optimal algorithms are often used. In the article, the decisive algorithm based on game theory and the algorithm based on competition theory are both introduced. Moreover the competition algorithm(CA) is improved largely. These two algroithms reduce the complexity from different way. The experiments indicated that they could be used in the segmentation of complex remote sensing image effectively. In the system constructed by the method, the cotton areas are extracted with high precision from satellite image.6214|915|0更新时间：2024-05-07
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- 摘要：Directly painting textures on top of 3D objects in 3D perspective viewport is a new issue of Human Computer Interface (HCI).This paper presents a method to solve this issue.It converts the position information of the texture pixels of texture map into color information,and then transfers both the coordinates and the color of texture pixels into screen through texture mapping at the same time.Only is the color information of texture pixels converted into illumination by calculating the normal and the angle of ray incidence of the screen pixel in the method.The texture coordinates are firstly converted into the color information by generating another texture map,which is called information Map whose pixels' color represents the coordinates information.And then the corresponding texture coordinates are mapped into screen reference frame by texture mapping and stored into information buffer for later use.So we can obtain the texture coordinates of screen pixels correspondingly by decoding from information buffer.After optimizing,we can paint textures on top of 3D objects in 3D perspective viewport in real time.The paper also gives some examples and related definitions of using additional information of 2D texture map for 3D graph generating.2590|380|0更新时间：2024-05-07
- 摘要：Shot clustering is an important issue in the field of video content analysis.The basic task of shot clustering is to classify shots based on their low level physical features.This paper describes a novel shot clustering technique.Beginning with an initial classification of the shot set,our algorithm proceeds with merging and splitting iteration alternatively to reduce the errors in the initial results.The initial classification is based on the closeness of shots.The following clustering process is controlled by merging and splitting rules,which are based on the concepts of centroid,radius,intra cluster hole,and inter cluster space.The basic idea is that:(1)the intra cluster hole of a cluster should be less than the intercluster space; and (2)the centroid distance of two clusters should be larger than the sum of their radiuses.Special consideration is put on the design of the iteration mode to suppress the possible errors.The main advantage of this algorithm is that it does not need any experiential parameters or thresholds,neither does it need any manual interaction,which is a basic requirement for automatic clustering of shots with no domain knowledge.Experimental results are presented and analyzed.2671|436|0更新时间：2024-05-07
- 摘要：Key color effect is commonly used in video and film editing.In this paper,the concept of Alpha channel has been described and algorithms of the key color effect have been thoroughly studied theoretically.A mathematical model that foreground image can be seen the overlay of the video object and background of this image has been established.Based on this model,the matte equation and its general formula are obtained.By discussing the special case that a desired foreground video object is separated from two backgrounds of constant color (blue and black),a double foreground technique has been presented.Corresponding theorems that can pull a matte on any color object against random backing have been given and proved.We pulled the foreground video object from a complicated background and even object that includes backing color from constant color background by this technique with C language programming.Any other key color effects cannot realize these.4216|425|0更新时间：2024-05-07
- 摘要：Keyframes are still images, which best represent the content of the video sequence in an abstracted manner, and may be extracted from original compressed data. Keyframes are frequently used to supplement the text of a video log, but there has been little progress in identifying them automatically. The challenge is that the extraction of keyframes needs to be automatic and content based so that they maintain the important content of the video while removing all redundancy. Up to now, more and more video materials are stored and transmitted in the compression data, so it is practical to study a unified approach to extraction of keyframes based on compressed video data. In this paper, we present a system for extraction of keyframes, which is based on different formulae comparing discrete cosine transform(DCT) direct current(DC) coefficients over the I frames in MPEG video stream, and for which only minimal decoding is needed. In theory semantic primitives of the video, such as interesting objects, actions and events should be used. However, because such general semantic analysis is not currently feasible, we explore two methods instead, in which one is from the idea of dot in mass, and the other is based on the number of unequal macro blocks.3931|550|0更新时间：2024-05-07
- 摘要：The dynamic non interference judgement problem refers to the judgement on non interference between two geometric figures in relative motion at any instance which often occurs in layout optimization,route programming for robots,dynamic simulation,etc.It is of great computational complexity and is to be further discussed.This paper mainly deals with the case of two rectangles.According to the theory of the No Fit Polygon and rectangle's geometric feature,the authors give the rules of the judgment,the proof of the rules ,and the simple formulas to compute the apex of the No Fit Polygon(transformed into symmetrical octagon).As a result,the non interference algorithm of above two dimensional geometric figures is established.This algorithm is simple and efficient.In particular,it is suitable for the judgment on non interference between two rectangles in relative motion at any instance,so it is of the certain value of application.10147|2318|0更新时间：2024-05-07
- 摘要：A new method of automatic creation of topological relation between contours by constructing the\n“topologic contain binary tree”is discussed in this paper,and based on the binary tree data structure a fast color fill application is proposed to commendably realize the vector effect of contour color fill graph in random scale,random height interval,random boundaries surroundings.From the relationship between boundary lines and contours,the topologic relation among contours can be built and stored in the tree structure.Such a topologic structure displays the linking and closing between boundary lines and unclosed contours,the nesting among closed contours in the order of tree rings.It is successfully applied in visualization and automatically mapping of submarine topographic data observed by multibeam, and it overcomes the insufficiency of contour mapping produced by common algorithm,especially conquers the inconsistency between color blocks and contours produced by mapping software for multibeam postprocessing.3456|581|0更新时间：2024-05-07
- 摘要：Matching and estimating motion are basic problem of computer vision. Classical methods are first to find the matching point (or line etc.) and then estimating motion. This paper discussed the application of Clifford algebra (Geometric algebra) in the area of computer vision, presented the uniform formula of 2D and 3D rotation and their application in matching and estimation motion of the line segments model. Based on improving the algorithm of matching 2D polygonal arcs in reference [4], this paper provides an algorithm solve both of matching and estimating motion simultaneously using Clifford algebra. Via minimizing the distance between the model and the detected characteristic (the distance measure is defined as the integral of the Euclidean distance between corresponding points), The algorithm results with that the rotation of the best estimation can be represented by the SVD of a matrix. To our knowledge, this paper is the first investigation to solve both of them. And the algorithm is free from the dimension of the line segment model. Synthetic data has been used to test the algorithm, and excellent result has been obtained.3452|539|0更新时间：2024-05-07
- 摘要：In the field of computer vision,it's difficult to get the disparity of features from stereo images.In this paper,a binocular filter based on anisotropic competition which adapted from FACADE theory to find disparity of features is proposed.Binocular filter use cells activity to represent the disparity distribution of features.There is competition between cells before the disparity distribution of features is acquired.Because of the horizontal bias of “eyes”configuration in binocular vision system,features with different orientation must be processed differently. Anisotropic competition is used in order to consider features with different orientation in a uniform way.The method of anisotropic competition better the performance of FACADE model by favoring the self-organization of cell activities.This approach is much different from the traditional method of matching the elements in the two images,which provides a different view of computer vision research.3065|408|0更新时间：2024-05-07
- 摘要：In 2D vector field visualization,the texture based methods represent the field structures globally,and have become attractive alternatives.In this paper we presents a new texture based technique:Streamline Texture Synthesis(STS).Many 1D textures which have high strong directions are synthesized firstly.STS uses a random 1D texture to texture map each streamline,then synthesizes texture mapped steamlines.In local vector field region,the steamlines are approximately parallel,so a streamline can be drawn thicker in order to accelerate computing.The thickness of a streamline is set based on the critical point of a vector field.The thick streamline is rendered as many parallel streamlines,then many 1D textures are used to texture map them.The STS can generate animation by cycling through 1D texture.The analyzed result proves that STS can produce substantially better visual results and STS is fast enough to visualize vector field interactively.3418|445|0更新时间：2024-05-07
- 摘要：It's difficult to build a 3D stratum model based on surface model because the stratum is multi-layer structure. For example, Shape from planar contours is often used in stratum modeling but correspondence problems、tiling problems and branching problems are difficult to be solved. Volume elements can describe both surface and interior of the model. In this paper, a method based on tri-prism is used to build a stratum model. The algorithms of sections and incisions of model are presented here in detail. This method is perfect to model the stratum of layer-structured. Some virtual operations of stratum can be easy realized in computer. The results of application show that the approach introduced here is practical and effective in 3D stratum modeling.3527|510|0更新时间：2024-05-07
- 摘要：D dynamic interactive visualization via Internet becomes the main trend of modern cartography along with the fast development of WWW and Virtual Reality Modeling Language (VRML) which can run in Internet,Intranet and local system.This paper studies on the technical characteristics of VRML and explores the potential of its application to modern cartography.The conceptual approach and prototypical practices have been researched with the combination of Visual C .The main works are focused on (1) the experiment of large data volume of 3D terrain of Beijing area by VRML 2.0; (2) developing a prototype system of 3D dynamic interactive visualization,and applying it to the visualization of Beijing population change.These applications are successful.The experiences in the practices show that VRML 2.0 is limited for interactive dynamic visualization of geo applications. Furthermore,the capabilities of browsers and plug ins influence the display of VRML applications and have to be more standardized.3143|505|0更新时间：2024-05-07
- 摘要：Shape recognition is a very important problem in computer vision.Geometric shapes can be divided into two classes: regions and single pixel structures.Hu's invariant moments are often used as features for characterizing shapes of regions.However when applied to structures,Hu's moments lose scale invariant.Chen proposed a method based on region boundaries to speed up the calculation of Hu's invariants.In this paper we extend Hu's and Chen's methods to define 10 relative moments,which are independent of position,scale and orientation.The formula of invariant relative moments we proposed can be applied to both regions and structures.Experiments show that the invariant relative moments recognition are effective to shape of regions,closed and unclosed structures.This method is also more convenient than Fourier Descriptors.3092|564|0更新时间：2024-05-07
- 摘要：In this paper a method of image merge on micrograph is given, which introduces the template matching technique into image merge. Other problems occurred in the new application is also discussed. such as relative position nice adjustment of image. Template matching is more simple and effective than other methods of image merge fot that image which has no or small transform. Filter matching is one method of template matching. Since we don't know the noise function of the filter matching model in most cases, we hardly to use it directly. We do some pre process to make it work. Our method of image merge consists of three steps:template selection, template matching, and image align. To reduce the influence of noise we select the template on the basis of image segmentation. After template matching, both images are in alignment by rotating one image with an appropriate angle obtained from a multi resolution searching. The experimental result shows that our method is effective, simple and easy to use for micrograph merging.2929|482|0更新时间：2024-05-07
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