最新刊期
卷 6 ， 期 12 ， 2001
- 摘要：As one of a serial of reports, this paper is a survey on multimedia researches and applications in China, 2000. Since multimedia is a cross research area, papers about multimedia technology are distributed on various journals. We saw about 4 633 papers published on 14 Chinese journals in 2000, from which we selected 521 ones on multimedia technology and application, then we made analysis on them, and the classified data were compared with which of 1998 and 1999. Looking into the data we can see that researchers in China pay more and more attention to human computer interaction, multimodal interface, digital watermarking, virtual reality, multimedia data retrieval technology, distributed multimedia supporting technology, GIS and Digital Earth, which are also the international evolution trends in a quite long period. We present here an overview on the progress in multimedia technology in China, 2000. This will be convenient for researchers looking up references, and helpful for editors compiling journals and for authors contributing papers.2364|336|0更新时间：2024-05-07
- 摘要：In this paper, based on the Lifting Scheme algorithms of the wavelet transforms with the compactly supported biorthogonal filters, the operator matrices of the forward wavelet transforms and the associated inverse wavelet transforms are constructed. These matrices are the inversive constant ones and have the size as the same as the length of the signal. These operator matrices are very convenient tools to analyze the properties of the biorthogonal wavelet filters in a theoretical way. These operator matrices can also be used for analysis the performance of the biorthogonal wavelet filters in different applications. In this paper, by these matrices, the de correlation performance of several biorthogonal wavelet filters in data compression application is studied in a view of theoretical analysis. The qualified quantities are given in comparison with other popular orthogonal transforms such as DCT and DFT. Experimental results demonstrate that different wavelet filters have different performance in the data compression applications. In the case of the high compression ratio, (9,7) filter has the better performance while in the case of the moderate compression ratio, (5,3) filter has the better performance.2548|351|0更新时间：2024-05-07
- 摘要：In a subband image coding system, due to the non ideal characteristics of the analysis/synthesis filters and the decimation/interpolation operations, the reconstructed signal, in general, suffers from magnitude/phase distortions and aliasing errors. For finite length sequences (e.g. the image signals), besides the above errors, there is an additional error--the expansive effect around the borders due to linear convolution. Though the conventional symmetric extension and circular convolution are applied, the experiments show that the border distortion still exists in the reconstructed signal. The symmetric extension method is further studied in this paper and extended to the M channel linear phase perfect reconstruction filter banks. In this paper, different symmetric sequences are formulated in a unified form based on the circular symmetry framework. According to the period and the symmetric center of symmetric periodic sequences, four permissible types of symmetric extension are derived. The experiment shows that the reconstructed signal is free from distortion.2768|289|0更新时间：2024-05-07
- 摘要：In this paper, the MSE in IFS image compression is analyzed. The concept of generalized creditability is presented. Based on that, the algorithm of the adaptive threshold(AT) IFS image compression using quadrature partitioning structure is proposed. To improve the compression ratio of the AT algorithm while still keeping the visual performance of decoded image, the formula of the adaptive threshold is revised according to the relative complexity of each range block, which forms the revised adaptive threshold(RAT) algorithm. The methods proposed in this paper set the threshold of current range block according to its statistics character, that is, variability. Therefore, the encoding process is adaptive to the complexity of the input image. Experiments results of algorithms based on AT, RAT and fixed threshold are given in this paper as comparison. The results show that RAT algorithm can compress the input image adaptively and the compression efficiency is improved considerably. Also time consumption of each algorithm is discussed at the end of this paper.2606|343|0更新时间：2024-05-07
- 摘要：In many reasons of causing image quality degraded, disturb and influence of noise source are important reason of causing image quality degraded. It is necessary that removing noise for improving image quality. At the same time, It should not be damaged that the edge and detail of image to the best of our abilities. In this paper, aim at the problem that omni directional multistage combination filter fuzz the edge of image while removing noise,the reason of causing this problem is analyzed and another advanced omni directional multistage combinative algorithm is proposed. It is pointed out that should take the special cases of corner lines tread into account for solving the problem. The algorithm proposed can preserve the edge of image very well when removing noise. The result of experiment shows that this filter can preserve much more edge information of image when removing noise and achieve better effect.2333|327|0更新时间：2024-05-07
- 摘要：Edges of objects often provide important features in pattern recognition application. How to extract the edge effectively in noise image is a difficult problem in the field of image analysis. Heuristic search algorithm is often used to extract edge, but because this method utilizes the fixed start points, fixed guide measurement and processes one off search, it is often very sensitive to noise. In this paper, a stochastic heuristic search method is presented. It firstly uses repetitive random searches to obtain various possible independent edge trajectories, then self reinforces and accumulates the search trajectories respectively, at last, extracts the edges relying on the result of the accumulation of self reinforcement. Lots of experiments show that our method can extract edges effectively and suppress the noise at the same time. Comparing with heuristic search algorithm, we find that our method is superior.2473|316|0更新时间：2024-05-07
- 摘要：A method of JPEG2000 based scalable lookup of image's local regions is presented in this paper. At first, we compress the image with the baseline algorithm of JPEG2000. Then we arrange the compressed data in light of zerotree structures, each zerotree is corresponding to a local region(mesh) of original image. When we want to look up a target on the image, we first browse the lowest resolution subimage(LL subimage) and locate mesh which the target belongs to. Then we reconstruct the mesh level by level in both spatial revolution and Signal to Noise (SNR). In this way we use only part of the compressed data to reconstruct the local region of image and show the target. It can save much computation resources. In the end of this paper, the experimental results of JPEG2000 based scalable lookup of image local regions are given.2830|319|0更新时间：2024-05-07
- 摘要：Multiwavelet is a new kind of wavelets and application of multiwavelet to signal processing is also a new practice these years. Perhaps this is why we hardly find the statistical data such as mean, variance and the proportion of zero valued quantized coefficients of multiwavelet transforms in literatures. In this paper, we collect five multiwavelets from literatures and Internet and make a statistical analysis of their performance in multiwavelet transform. From our analysis we can conclude that (1) After CL multiwavelet transform, the energy of an image will converge not only to the lowest resolution subimage, but further to the first component of the subimage. Therefore, CL multiwavelet is most qualified for image coding. (2) After CARDBAL multiwavelet transform, the energy of the lowest resolution subimage of an image will spread in average among its four components. Therefore, CARDBAL multiwavelet image coding has to appeal to correlative coding between the components of subimage to improve its compression ratio. (3) After GHM multiwavelet transform, the distribution of the lowest resolution subimage's energy is not concentrated on one of its components, not averaged among its components. Therefore, GHM multiwavelet is not particularly suitable to image coding, even though it is the first multiwavelet to be discovered and now widely used in applications.2515|314|0更新时间：2024-05-07
- 摘要：The paper discussed application technology about composite material preform stitch measured using wavelet transform. The system is rested on the multi scale analysis of wavelet transform. By selecting appropriate wavelet basis, the surface image of composite material preform may be processed and show ideal information of image edge. When a texture template selected, match point about iamge will be make out by revolution algorithm. Through measuring distance of match point, the stitch of perform may be brought out. When compared with other filtering mode, it proves that wavelet transform can reduce noise while preserving image edge features. The experiments show that tested results are consisted with handiwork. This system proved that it is possible for stitch of composite material preform will be analyzed using wavelet transform.2629|371|0更新时间：2024-05-07
- 摘要：In this paper, a particular review on traditional remote sensing statistical analysis model is made and their defects are analyzed from several aspects especially brought by the statistical assumption of its unimodal probability density functions and parametrical density distribution model. On the basis of traditonal statistical model, some intelligent ways of extensions are proposed, where the major attentions are paid on integration with geo knowledge processing unit and computation with other artificial intelligence approaches such as fuzzy logic, conventional geo analysis, robust statistics, neural computation, and evolutionary computation. Finally, several detailed approaches of extensions of statistical remote sensing analysis model, such as RBF, GMDD, and knowledge integrated model, are introduced and discussed briefly.2549|427|0更新时间：2024-05-07
- 摘要：The problem of liner objects skeleton detection from remotely sensed image is an interesting and challenging one in the correlated field. In order to extract the linear objects skeleton speedily and efficaciously from remotely sensed image, this paper presents a detailed summary of the properties and basic facts about direction changed skeleton tracing method of liner objects based on its various appearance in image. Geometric continuity constraints are of special interest, as they appear to satisfy visual needs of the human observers. Examination is made of the many different liner objects conditions. Experiments detected large numbers of complex properties of linear object skeleton show that the result approximate to manpower distinguish, at the same time this algorithm is better in terms of accuracy, robustness and the computational speed is quite rapid. So it is worth discussing for craft brother.2592|325|0更新时间：2024-05-07
- 摘要：In the paper, an on|line ship detecting system based on the probability velocity field is presented. First all environment factors that ships go through the ship lock are analyzed, such as lighting, shading, waving and so on; Second, a Gaussian probability distribution model(probability field) is generated from gray|level histogram to diminish the affection of shades and speckles, since shades and speckles' gray|levels are distributed in both sides of gray|level histogram, after histogram is fitted with the Gaussian distribution function, the probability of them is smaller than that of other gray|levels. Therefore a probability velocity field is defined and derived based on the optical flow to detect ships in lock on|line. The velocity field is calculated by the traditional optical flow estimation method using the probability of gray|levels, not the gray|levels. Finally the affection of shading and lighting is reduced greatly. The method has succeeded in testing a larger number of image sequences that ships pass through the temporary ship lock of the three gorges project(TGP) and ship lock of the Gezhou dam.2585|339|0更新时间：2024-05-07
- 摘要：This paper introduces author's work in compress to vector spatial data, which will be transported in Internet/Intranet. On the basis of vector spatial data compression method, which is proposed by[1], the authors proposes next four innovation:(1)For vector spatial data, not only integer but also short data can be used to replace traditional double or float data. (2)The map data are mapped to a“virtual screen”, the formula of“virtual screen”width is: width=DispWidthPixel×MaxEnlargeRatio/stepWidth①. (3) In the mapping process, execute “filter points compression”to pattern points of arc(including polygon' s boundary arc and line' s arc). In the formula①, if stepWidth=1,“filter compression”has no loss in precise of map displayed, else stepWidth>1, it has precise loss in map displayed. (4)“Long edge adding point”to deal with exception of“Offset compress”to pattern points in arc, which offset in adjacent two points may larger than 127. After these compressions, a map vector data may be compressed to 20% or less.3298|384|0更新时间：2024-05-07
- 摘要：In this paper, a new method for automatic extraction of ridge and valley axes from DEM, named as Directional Profile Approach(DPA), is proposed. DPA can automatically determine whether a grid point in DEM is a possible ridge(or valley) grid point, according to the features of the profiles through this grid point. Applying this new method to extracting ridge and valley axes automatically from DEM, the following several procedures must be accomplished: First, the all elevation grid points which may be located in ridge and valley lines are automatically recognized with DPA. Then the modified Hilditch thinning algorithm is applied to selecting the ridge and valley grid points recognized by DPA. Third, the every two neighboring ridge points or valley points are connected and rudimentary form of the ridge or valley axes is constructed. Finally, the closed triangles in ridge and valley axes are broken and the short branches are removed. A real DEM was used for testing data, the ridge and valley axes extracted automatically by this method can basically represent the topographic features of the corresponding topographical map. Therefore, this new method is effective.3683|365|0更新时间：2024-05-07
- 摘要：With developing of Internet/Intranet and multimedia technology, multimedia surveillance systems have been shown to be digital and intelligent. this paper gives a detailed introduction on design policy, system architecture as well as realization methods of WebEye, an IP Multicast based multimedia surveillance system designed by us.Due to utilizing Internet infrastructure service IP multicast Technology, monitor signaling can be fanned out from center without additional bandwidth as Real time AV streaming, warning and control signaling can reach every network node which is interested in a particular transmission simply "turn in" by subscribing to the multicast group in question. WebEye has a good expansibility and practicability.2324|341|0更新时间：2024-05-07
- 摘要：In this paper, we briefly classified the several major continuous graphic transformations current in use in the area of computer graphics. Long till now, many graphics organizations or companies have their own unique graphics transformation methods. It seems they do not care for the goodness of other people's implementing methods. But in fact, many of their methods are similar in a sense. So, it is valuable to classify these various different graphics transformations into several major categories and make each one know what category his method belongs to and what goodness the other transformation category has. Besides, we had proposed a new solution to the application of implied matrix method, a most important continuous graphic transformation method, in the construction of graphics objects. In the concrete, we have solved the following problems: For a giving pointP, let it rotate an angleθ1 round the spindleR1and reaches pointP1, thenP1in turn rotate an angleθ2 round the spindle R2 and reaches point P2, Can we combine these two rotations? In other words, Can we get a spindleR3and an angleθ3 so that P just rotate the angleθ3 round R3 and it will reach P2, the resolution to this problem result in a software's generation which is much like the famous 3D Max.2904|334|0更新时间：2024-05-07
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