最新刊期
卷 11 ， 期 6 ， 2006
- 摘要：This paper is the eleventh of the literature bibliography on computer graphics engineering in China in 2005. We collected and classified most of important papers in computer graphics field published in Chinese, selecting references from 11 important Chinese journals published in 2005 and classified these references into different categories according to their contents. Based on the overview and analysis work, we found that the number of researchers and developers engaged in computer graphics-related field is increasing a lot in the past 10 years,and many conferences are held each year, many highlevel achievements are made in China. In addition, computer graphics develops itself, deriving out some new research topics or directions even cross disciplines.关键词：graphics engineering;graphics processing;computer graphics;technique application;survey2698|326|0更新时间：2024-05-07
- 摘要：With the development of wireless network and multimedia technology, error control technology in video coding and video transmission over lossy channels has been widely studied. This paper reviewed the error-resilient coding and transmission technology, including encoder based error resilience, decoder based error concealment, network based error control and joint source and channel coding. In error resilience, redundant information is added into the bitsream to confine the error propagation. Error concealment estimates or recovers the losing data making use of the character that most nature scenes change smoothly between neighbor blocks. Network based error control, joint source and channel coding utilize the channel feedback information to guide the encoder to make an optimum decision. Additionally, error resilient tools in the latest video coding standard H. 264/AVC and the preview of the future error resilient technology are also considered. Experiments indicate that the proposed error resilient methods are effective in video transmission over lossy channels.关键词：error reslilient coding;video transmission;error concealment;joint source and channel coding;H.264/AVC4426|535|0更新时间：2024-05-07
- 摘要：Since CBERS-1 was launched in October 1999,it had been running normally more than 4 years to 2004 and received tens of thousands of images.This paper introduces some key techniques,such as removing streaming noise of CBERS-1 images,image enhancement,geometric correction,image mosaic,and color adjustment.What's more,this thesis introduces the work flow and cartography criterions of using CBERS-1 images make China digital mosaic map.关键词：CBERS-1;remote sensing image process;map mosaic2717|253|0更新时间：2024-05-07
- 摘要：The end-to-end error propagation distortion on pixel level precision is analyzed based on temporal concealment strategies in decoder and channel error rate. By using frame correlative coefficient and concealment ratio of TR and MCR, a new general transmission distortion estimation model for various temporal concealments is proposed. The estimation accuracy is demonstrated via simulation results for video transmission over packet loss channel, which illustrates that actual distortion can be estimated by proposed expectation model approximately. The proposed model provides an efficient method for MB coding parameters optimal selection over error prone environment. The simulation results also show that the MB mode INTRA-update algorithm based on proposed model has better substantial and consistent gains than traditional R-D optimal INTRA-update algorithm.关键词：video coding;error resilient;rate-distortion optimization;end-to-end distortion2576|282|0更新时间：2024-05-07
- 摘要：This paper proposes a template matching algorithm in Fourier transform domain(TMFT),which is robust against geometrical transformations in spacial domain,and makes the template matching to be a prototype matching.Time-shifting of signal in time-domain is eliminated by time-shifting property of FT. Disturbance out of signal intensity is Normalized by the auto-correlativity R(0).Energy distributive function is introduced to keep the correlation between templates and target against the rotation relative to template signal. The experiments show that TMFT assures the constancy in template matching and is available to rid the correlativity of geometrical change in time-domain.关键词：matching;correlativity;constancy;geometrical transformations2535|310|0更新时间：2024-05-07
- 摘要：The model proposed by Chan and Vese using one level set function is not able to obtain sub-objects in the object because one level set can only represent one object and one background via its sign.To solve the problem,an algorithm for multi-layer object segmentation based on Chan-Vese(C-V) model is proposed.Firstly,an idea for multi-layer object segmentation is proposed after the analysis of the C-V model.Secondly,a key technique,named as the technique of painting background,is developed and proved following the theory of the simultaneous brightness contrast.Thirdly,the proposed algorithm is presented using the proposed technique and the C-V model.Finally,experimental results show that the proposed algorithm is especially effective for the detection of the sub-objects with weak boundaries in the object.关键词：C-V model;level set;multi-layer object segmentation;technique of painting background3342|320|0更新时间：2024-05-07
- 摘要：To overcome commonly-used filtering template's drawback and remove the ringing artifact& block effect in conventional image filtering,this paper presents 2D all-phase window filtering under arbitrary orthogonal transform.Based on the general calculating formula of 2D all-phase template under arbitrary orthogonal transform,the concise formula of all-phase template with window under DFT is deduced.The restoration experiment on the sub-sampled image proves that: compared with the template constructed by IDFT,the PSNR of the image restored by all kinds of all-phase template is above 7dB higher and ringing artifact can be eliminated.Another experiment shows that block effect in conventional block filtering can be completely removed by employing 2D all-phase DCT template.关键词：template;2D all-phase filtering with window;ringing artifact;block artifact;arbitrary orthogonal transform2689|291|0更新时间：2024-05-07
- 摘要：Traditional anisotropic diffusion methods always come from PDE(partial differential equation) itself.Which results in complex theoretic analysis.The inner orthogonal coordination based on the directions of the image feature is discussed in this paper.Subsequently,anisotropic diffusion methods based on the inner orthogonal coordination can be constructed directly.Which are more intuitionistic than the traditional methods,and can simplify the analysis in theory as well.A new anisotropic diffusion filtering method which is based on this framework is proposed in this paper.The numerical results show that the new method takes the local feature of the image into good account and can accomplish both detail-preserving and noise-removing.The anisotropic diffusion methods based on the direction of the image feature proposed in the paper is efficient and can get anticipate results.关键词：direction of the image feature;anisotropic diffusion;PDE(partial differential equation)2761|306|0更新时间：2024-05-07
- 摘要：The construction of the LOG template in edge detection by Marr algorithm is researched in this paper. According to the designing criterion, a digitization method using unequal interval sampling combined with non-uniform quantification is proposed. We deduced the general formula of constructing the LOG template and presented the adjusting method of parameters in the formula. The practicability of this method is proved by experiments.关键词：edge detection;LOG template;sampling;quantification2696|322|0更新时间：2024-05-07
- 摘要：As the active contour model(Snake model) is widely used in automatic missions,higher robustness and adaptability of the model are required.Due to the contraction,over-flatten effect on contour and scale variance of the traditional model,the adjustment of its parameter is quite difficult and hard to be automatically decided by program.Our constantly changing curvature based internal force model is scale invariant.Besides keeping the smoothness and continuity of the contour,no side effect is introduced and the robustness of model parameters is increased greatly.Experimental results show that the proposed model greatly improves the ability of detecting the accurate contour of the target,and even works well for the contour with high curvature position and concavity.Because of fast attenuation of internal force and insensitivity to addition and deletion of contour points,the model is guaranteed to converge quickly and steadily to the expected contour.关键词：active contour model;contour extracting;snake;constantly changing curvature;scale invariant3038|382|0更新时间：2024-05-07
- 摘要：This paper is based on taking the masking characteristics of the human visual system into account.First,we give the method that can calculate the just noticeable difference(JND) matrix.Secondly,we propose a public watermarking of gray-level still images combining DWT and DCT.The results of experiment indicate that this watermarking scheme is much robust against noise interference,some geometric distortions and commonly used image processing techniques,especially the signal enhanced processing almost can not affect the correct extraction of watermark.关键词：discrete wavelet transform;discrete cosine transform;the coding of range supervised;human visual system;Hilbert scanning3164|318|0更新时间：2024-05-07
- 摘要：A new image blind watermarking algorithm based on adaptive quantization step in discrete wavelet transform(DWT) is proposed,which can be used in copyright authentication.In the proposed algorithm,the perceptually significant coefficients are selected from LL subband to be the embedding domain,and a minimum quantization step,which guarantees the invisibility and robustness,is used to quantify the selected coefficients.The binary watermarks are alternately embedded on the different quantified levels by adaptively increasing the quantization step.As a special example,the least 5 bits of the selected coefficients are utilized to express the watermark.Considering the localization character of wavelet transform in spatial domain,a block-based rounding method is adopted to achieve the purpose of precise embedding.As to the detecting algorithm,a novel difference detecting algorithm is created to improve the robustness of system.The experimental results show that the proposed algorithm has the following characters: large information capacity,invisibility and robustness against attacks such as some common image processing operations,lossy compression,cropping and some geometric transformations etc.关键词：discrete wavelet transform(DWT);image watermarking;block-based rounding;difference detecting;quantization step2764|347|0更新时间：2024-05-07
- 摘要：The color of solid texture space is defined traditionally through a function model.To simulate different texture details,the relevant parameters need to be modified and tested repeatedly,however good results could rarely be acquired.A new method of solid texturing based on specimens is proposed in the paper.We establish geometrical mappings between the specimen space and solid texture space according to the structure characteristic of wood texture,and define the color of solid texture space using the texture value of specimen pixels.The results from our experiments show that the wood texture produced by this method successfully represents realistic texture details on the specimens and is continuous between the conterminous surfaces of objects.As the wood specimens may be selected according to user's requirements,solid texturing based on specimens is a superior technique which could evidently promote the quality and the variety of wood texturing.关键词：texture mapping;solid texturing;wood solid texturing;specimen3535|492|0更新时间：2024-05-07
- 摘要：Fingerprint image binarization, as one key step of fingerprint image preprocessing, is the precondition of fingerprint image thinning. In order to utilize the texture character of the fingerprint image effectively, the paper introduces the orientation information in fingerprint image binarization. After considering the fingerprint image orientation information and self-adapt local threshold synthetically, this paper brings forward a kind of self-adapt local threshold binary algorithm using the orientation information. The contrastive experimental results indicate that the presented algorithm can achieve more exact binarization results than the self-adapt binarization algorithm. Moreover the algorithm can repair the disconnected line in the fingerprint image in a certain extent. The algorithm is important for improving the minutia extraction precision.关键词：fingerprint;automatic fingerprint identification;binary processing;orientation information2590|324|0更新时间：2024-05-07
- 摘要：Most of the presentpedestrian detecting algorithms can notdealwithmulti view objects and can notperform in real time. Faced with these problems, this paper provided a real time multiview pedestrian detecting algorithm, which utilizes respectively the color and the contour features to construct two detectors. One is a color based detector, which, first, segments the original images based on skin color of face and hair color, and then locates the candidate head regions by using integral images, and the other is the contour detector, which employs the robusthead shoulder contour feature to construct a deformable template based on two ellipseswith size and position constraints. Two templatematching algorithms with different computing complexitywere introduced to detecthead shoulder objects. Finally, a cascaded detecting system was generated by the two detectorsmentioned above. The whole system can process imageswith 352×288 resolution at a speed of 30fps by using the cascaded structure. The algorithm proved to be effective.关键词：pedestrian detection;color segmentation;head-shoulder contour;integral image;deformable template;cascaded detection2829|385|0更新时间：2024-05-07
- 摘要：Gait recognition refers to automatic identification of an individual based on his/her style of walking, which is a new biometrics recognition technology. This paper attempts to describe gait contour by using the distance between the contour centroid and the pixels on the edge, to make quasi-periodic analysis on height and width ratio of gait image, and to solve the problems resulting from image sequence of different gait cycle by HMM. By utilizing the algorithm in the paper, the experiments with CMU database have achieved comparatively high correction identification ratio.关键词：biometrics;gait recognition;feature extraction;hidden Markov model3163|386|0更新时间：2024-05-07
- 摘要：The Euclidean Distance Transform(EDT)converts a binary image into one where each pixel has a value equal to its Euclidean distance to the nearest foreground.It has important applications in image analysis and computer vision.This paper gives an algorithm for complete Euclidean distance transformation on the binary image on the basis of the contour scanning.In the suggested algorithm all the pixels are classified and the ones which neither are characteristic pixel nor have characteristic pixels in 4-neighbors are marked.For the marked pixel,scan its contour form inner to outer,find its nearest characteristic pixel and compute their Euclidean distance.The exact distances are obtained.The requirement of time are analyzed briefly,some testing data produced in running the implementation are illustrated.The result shows that the algorithm runs fast,the requirements of space and time are satisfying in the present hardware condition,and it is an effective and enormous applied distance transformation algorithm.关键词：binary image;contour scanning;complete Euclidean distance transform;time complexity;image analysis4399|302|0更新时间：2024-05-07
- 摘要：Feature correlation matching is a very important method for target tracking. Intensity and edge are two main kinds of target features. Under occlusion, the tracking feature should be chosen depending on the characteristics of the target. This paper estimates the intensity characteristic of target firstly, then choose the edge matching or intensity matching algorithm based on the narrow or wide intensity ranges of the target. The edge matching method determines the optimal displacement vector between two successive frames by matching of the target edge template and the current unoccluded edge, and the template is updated in real time. The intensity correlation matching based on multi-block method can estimate the occlusion region accurately through the blocks with distinct feature, and track the target by the remaining unoccluded blocks. Experimental results show the good performances of the proposed algorithm.关键词：target tracking;occlusion;edge correlation matching;intensity correlation matching2676|390|0更新时间：2024-05-07
- 摘要：The topic of uncertainty management is a new issue in spatiotemporal database research. Some efforts have already been made on the indeterminacy representation models, while the area of topological relations models for indeterminate spatiotemporal objects remain untouched. The goals of these models are to provide a set of Joint Exclusive and Pair wise Disjoint topological relations for uncertain spatiotemporal objects. This paper presents a topological relations model for indeterminate evolving 2D regions. It checks the correspondence between 3d topological relations and spatiotemporal relations, provides restrictions to make the 3d relation model fitful for spatiotemporal objects. Then it extends Egg/Yolk model to the third dimension that can describe the approximate topological relations for indeterminate evolving regions. The result is a collection of relations clusters which have different spatiotemporal nature.关键词：spatiotemporal database;topological relation;uncertainty2734|294|0更新时间：2024-05-07
- 摘要：The template matching algorithm of digital image is studied to improve the matching speed that is critical for the semiconductor packaging industry. The moment matching of circular windows is a fast algorithm, which divides the template into a series of circular ring and computes the moment of corresponding circular ring between template and source image to find the matching point. But the arithmetic product operation is needed to determine a pixel belonging to which circular ring, which consumes much time. For this reason, an improved algorithm by using a distance map before matching is proposed. The radius is stored in the distance map to record the distance between each pixel and the center of circular rings. Thus, simple comparison operation on the indexes of a pixel can determine a pixel belonging to which circular ring, which can save much time. Experiments show that the improved algorithm can improve the matching speed greatly and meet the needs of precision electronic packaging.关键词：circular window;moment matching;distance man2999|330|0更新时间：2024-05-07
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