最新刊期
卷 3 ， 期 2 ， 1998
- 摘要：A set of local interaction field and adaptive regularizers are introduced to usual regularization theory. A local interaction field consists of a usual error term and a window function. The sizes, orientations and shapes of window functions can be made adaptive to specific applications. Adaptive regularizers are used to handle discont inuities. Theses two terms lead to asymmetrical energy functional. Even the simplest gradient algorithm is effective and stable when there are noises or algorithmic parameters change.关键词：Regularization theory;Local interaction field;Adaptive regularizers;Visual representation;Surface reconstruction;Image smoothing2265|137|0更新时间：2024-05-08
- 摘要：This paper makes an improvement on the fractal image coding algorithm proposed by Y. Fisher. Three-layer classification method and multi-resolution matching method are presented. By applying these methods, a new fractal coding algorithm based on quadtree partitioning is implemented. Experimental results show that the encoding speed is much enhanced while the compression ratio is about the same and the peak signal-noise ratio is a little higher.关键词：fractal;Image compression;classification;match;Adaptive partitioning2119|146|0更新时间：2024-05-08
- 摘要：Relaxation labeling refers to a class of algorithms for assigning a label to each object in a graph, by iterating a transformation until a fixed point is reached. A probabilistic relaxation method is analytically derived in this paper, and a stochastic relaxation algorithm is also carried out step by step. We employ the MRF-Gibbs equivalence to calculate the local characteristics of the MRF, and take the maximum entropy (ME) estimate as the conditional neighborhood probabilities. At the last section of the paper, the two distinct approaches are compared and contrasted.关键词：Probability relaxation;Stochastic relaxation;Markov random fields;Gibbs distribution;maximum entropy3354|130|0更新时间：2024-05-08
- 摘要：The principles of the 2nd generation wavelet transform is discussesed. Through lifting algorithm, all transforms are processed in the spatial domain, which can be done by in-place operation. It will improve the computational efficiency while saving memory over loading. As an example, An implementation on how to construct the 2nd generation wavelet through lifting scheme using classical CDF biorthogonal wavelet is proposed. Combined lifting transform with linear filtering, we make an experiment on remote sensing images processing. It shows good effects on image enhancement and blurring.3285|154|0更新时间：2024-05-08
- 摘要：Multispectral imagery is one of sequence images. Usually, the frame compression of sequence images is based on the decorrelation between frames. To multispectral imagery, there is less correlation between frames. So the conventional frame compression is invalid. In this paper, we present a new lossless compression technique that based on classification to decorrelate spectral correlation and spatial correlation, we called it classification～based spectral prediction and spatial prediction (CBS2P2) method. The imagery was classified first, then was compressed by spectral prediction and spatial prediction. We created spectral pridictors with spectral vectors, for the gray values of image pixels were based on spectral vectors, and chosed the second mode of JPEG standard rediction modes for lossless compression as spatial predictors. The experiments with 6 bands SPOT data, 5 bands NOAA-AVHRR data and 6 bands TM data show the compression ratios can be improved.2559|161|0更新时间：2024-05-08
- 摘要：Given a finite subset W and a vector x both in k-dimension space, the method to fast locate the vector in W closest to x is of great value in applications. The fast search method plays an important role in the fields such as vector quantization method and pattern recognition using neural network. Based on the analysis of the fast search algorithm in Ref.[6], a new fast search algorithm is presented. Using the codebook addresses of neighboring image blocks as the predicting codebook address of current image block, the search space can be reduced more dramatically.关键词：Image coding;Predicting code vector;Image vector quantization2547|146|0更新时间：2024-05-08
- 摘要：In distributed computing environment, an important factor which will affect the performance of parallel algorithm is communication bandwidth. This paper presents a parallel volume rendering algorithm using a shear-warp factorization of the viewing Transformation on the local area network of PCs. We fully take use of the overlap of communication and computing to overcome the bottleneck of communication. In many parallel volume rendering algorithm based on object partition, local volume rendering and image composition are divided into two serial processes, in the period of local volume, the communication hardly happen, contrarily, in the period of image composition, the communication is very busy, even communication congest happen, furthermore there are a very big synchronism overhead in this period. The paper take use of Pipeline based on PC, local volume rendering and image composition are executed concurrently, the draw backs above are solved well. Our experiment which is completing on the Pipeline including 16 Pentium shows that communication do not affect the performance of algorithm, and the overheads are very little to rendering time. The paper provide a method for studying low-price, high-efficiency real-time volume rendering system.关键词：parallel computing;Parallel volume rendering;Distributed system2011|166|0更新时间：2024-05-08
- 摘要：This paper gives a new kind of recursive refinement algorithm which based on the analysis about the advantages of deRham method, cut angles method and 42 point method. It is agile to generate fractal by using the new algorithm. It can be widely used in the field such as irregular geometry shape simulation, visualmagic works manufacture, art design关键词：fractal;recursion;Refinement;computer aided geometric design;Line-art2678|161|0更新时间：2024-05-08
- 摘要：Fragile ecological environment is a unstable factor influence on live-supporting environment, lead to environment gradually deteriorated, in the paper processing from landscape and landscape ecology, first the meaning of mapping in landscape heterogeneity under landscape information flow determined by informatics, the measurement, the character and obtaining methods of landscape information flow have been discussed, in the meant ime, the way and expression of transform in landscape information flow pattern have been introduced. Second, the lanscape information effect in geoscience heterogeneity information has been discussed, in particularly the heterogeneity information in fragile ecological landscape has been analyzed. In further the mapping method of landscape heterog eneity in fragile landscape ecological environment based on GIS has been stated. Using date acquired by Landsat TM 1:250000 and 1:500 000 around 1990s and GIS in southeast of Horqin Sandy Land, combining with dates of investigated to the area from 1970s to 1980s, fragile ecological landscape heterogeneity map and land cover in the area have been provided.2862|212|0更新时间：2024-05-08
- 摘要：Urban growth simulation has a very important significance for rational adjustment and control of Urban System, and Residental spatial growth is a main part of urban spatial growth. Based on spatial interaction analysis among urban elements, resident spatial behavior model is built, and simulation system of urban residental spatial growth is built under the support of GIS and spatial analysis.关键词：Utility fuction;Spatial pattern;Spatial analysis;GIS2364|157|0更新时间：2024-05-08
- 摘要：Today, Geo-information Sharing and Open Geographical Information System become more and more important in Geo-infomation research field. Their research and achievements will carry all the field to a new stage. In this paper, The authors will talk about the main research contents, the relationship and the realizing techniques of Geo-information Sharing and Open Geographical Information System from the below part st: 1. Geo-information and Geographical Information System 2. The research contents and the present situation of Geo-information Sharing. 3. The technical supports of Open Geographical Information System. 4. The future of Open Geographical Information System and Geo-information Sharing.关键词：Geo-infoemation Access;Open geographical informarion system;Object technology;Distributed computing2402|146|0更新时间：2024-05-08
- 摘要：A laser-based active triangulation 3D information acquisition and reconstruction system is presented in this paper. This system can not only obtain the whole 3D data of object surface but also get rid of the missing problem. The measurement principle, calibration and reconstruction are described in details. The experiments demonstrate that the precision is 0.3mm with the 1m range. This method has the properties of hign accuracy, simple calibration and computation and wide application prospect.关键词：Active trinagulation;Acquisition;reconstruction;Calibration2567|154|0更新时间：2024-05-08
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