最新刊期
卷 12 ， 期 5 ， 2007
- 关键词：image engineering;image processing;image analysis;image understanding;technique application;survey;statistics;classification3221|242|0更新时间：2024-05-08
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- 摘要：Watermarking techniques for halftone images have been well developed recently. They are widely used for protecting the copyright of printouts and preventing card or ticket, as well as currency from illegal forgery. Firstly the principle and implementation of watermarking for halftone images are given. Then the analysis of direct-embedding methods, indirect-embedding methods and halftone visual cryptography methods is conducted. The comparisons show that the HVS-based indirect-embedding schemes have a promising application in the copyright control of paper products. Finally the open issues and possible future research directions are pointed out.关键词：data hiding;digital watermarking;halftone image;robustness3490|219|0更新时间：2024-05-08
- 摘要：Markov random field method is a very active research field in image segmentation. This paper introduces the relationship between a general theory based on Markov random field method and the images, and provides a general framework in image segmentation, including the construction of spatial and wavelet domain image models, the selection of the optimization criterion, calculation of the number of labeling, parameter estimation of image models and the realization of image segmentation. The applications of image segmentation are reviewed. And a few possible trends are discussed.关键词：Markov random field;image segmentation;Bayesian principle;parameter estimation5838|300|0更新时间：2024-05-08
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- 摘要：SVD preserves both one-way and non-symmetric properties. Based on the research and analysis of the first column of the orthogonal matrix after SVD, we propose a block-based image adaptive watermarking scheme based on the SVD of wavelet domain, embedding the watermark in the first column of orthogonal matrix, and selecting the best embedding coefficients by analysing the stability of those coefficients. The threshold, which is used to modify the selected coefficients is decided by the statistical properties of local blocks. The modification of coeffients is controlled by these two thresholds so as to obtain the optimal tradeoff between the transparency and the robustness. A large amount of experiments show that the proposed scheme is effective and robust to common image processing operations, especially to JPEG compression.2787|222|0更新时间：2024-05-08
- 摘要：A new geometric invariant video watermarking method is proposed based on DCT feature blocks that can satisfy the real-time embedding requirement. In the algorithm, certain number of DCT feature blocks are selected as the embedding points. The synchronization block is calculated accordingly for frame registration before detection is conducted. On the detection side, the feature blocks are firstly extracted for the localization of the synchronization block. And then neighborhood search is implemented on the synchronization block to accurately estimate the geometric distortion. After the frame registration, feature blocks are extracted again for the final watermark detection. Experimental results show that the watermarking system can resist to geometric attacks well with satisfying good invisibility, real-time and security properties.2692|199|0更新时间：2024-05-08
- 关键词：semi-fragile watermarking;DCT transform;JPEG compression2472|233|0更新时间：2024-05-08
- 关键词：video encryption;matching pursuit;security analysis2613|187|0更新时间：2024-05-08
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- 关键词：video coding;coding rate model;quantization step size;rate control2603|196|0更新时间：2024-05-08
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- 关键词：iris recognition;iris location;cross power spectrum;Gabor wavelets2657|189|0更新时间：2024-05-08
- 关键词：license plate;image pruning;maximum character pixels distance;margin detection;distributed information fusion2554|202|0更新时间：2024-05-08
- 摘要：The wavelet analysis is a newly arisen subject and it has been applied to image processing very well. With the advantages of the wavelet analysis edge detecting, we conducted a systemic study on the technology of detecting the image edge and seam recognition of V-groove. A seam recognizing algorithms based on wavelet transform is proposed. Based on the experiments on seam recognition, a method for detecting the image edge of V-groove and calculating the welding deviation is presented.关键词：wavelet transform;V-groove;seam recognition3145|215|0更新时间：2024-05-08
- 关键词：morphologie filter;tophat transform;baekground suppression;traek reeognition;bi-direetional ehain3136|205|0更新时间：2024-05-08
- 关键词：impervious surface;spectral mixture analysis;minimum noise fraction transform;remote sensing3497|234|0更新时间：2024-05-08
- 摘要：To obtain more efficient performance, taking color, texture and position feature in the images as their comprehensive features, an adaptive image segmentation method is proposed based on t mixture model and Greedy EM. The parameters of t mixture are estimated by Greedy EM algorithm . Image is segmented according to Bayes minimization error principle. T mixture model is robust and Greedy EM algorithm is less sensitive to initial parameters therefore it may be converged to the global optimum. Compared to other methods on image segmentation, the proposed method can accompush improved efficienty and better experimental results.3013|243|0更新时间：2024-05-08
- 关键词：active contour;deformable model;ellipse extraction;image segmentation2463|243|0更新时间：2024-05-08
- 关键词：muhimodal fusion;video semantic concept;muhilayer analysis;decision fusion3022|194|0更新时间：2024-05-08
- 关键词：volume data;porous media modeling;pore-network model;implicit surface3090|344|0更新时间：2024-05-08
- 关键词：iterated function systems;array factors;condensation;panorama model2605|243|0更新时间：2024-05-08
- 摘要：Constructing convex hull of planar point set is a basic algorithm in computational geometry. Although the number of current algorithms is increasing, most of them are quite complex. In order to reduce the algorithm complexity, the paper starts with analyzing the Plus or Minus Characteristic of Demarcation of a straight line. The purpose of step is to partition planar point set and to simplify the calculation distance from a point to a straight line. Then an improved algorithm is given which is seeking the convex hull of an arbitrarily distributing planar point set. This algorithm is simpler and the speed is faster than the popular algorithm which has adopted forward-backward method in searching convex hull. Our algorithm is also superior to the traditional algorithm. In particular it is unnecessary to compute the angle, Euclidean distance. Applying the algorithm to seek the convex hull of an arbitrarily distributing planar point set can obtain accurate, results through only addition, subtraction, multiplication and comparision. The method reduces the computing time for of each step therefore it is an optimal algorithm because of its efficiency.关键词：planar point set;convex hull;Plus or Minus Characteristic of Demarcation;the time complexity;distance3201|249|0更新时间：2024-05-08
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- 关键词：Dijkstra;shortest-path;priority queue;paring heap;VegaGIS4185|203|0更新时间：2024-05-08
- 关键词：cartographic generalization;quality assessment;skeleton-line;reducing-dimension processing2657|195|0更新时间：2024-05-08
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