最新刊期
卷 11 ， 期 11 ， 2006
- 摘要：In order to develop the application of mobile phone TV in Shanghai, we adopt L-band for T-DMB trial in Shanghai. Having set up the SFN transmitting platform for the wireless signal coverage of urban area of Shanghai, we made a measurement about coverage on road, adopted the CCIR model for the coverage estimate to compared the measured field strength, and proved the reliability of the CCIR model for the coverage planning prediction in high-dense-building city in L-band. According to the theoretical research and practical proof, two transmitting sites can achieve 80% coverage in Shanghai urban area, and CCIR is reliable for the prediction of coverage in super-large city as Shanghai which will be instructional for the coverage optimization in the future.2342|174|0更新时间：2024-05-07
- 摘要：When transmitting over the error-prone channels, the compressed video bit-steams are always vulnerable to all kinds of transmission errors. The corrupted parts of the bit-streams may not only affect the reconstruction effect of the current frames, but also cause the error propagation problems both spatially and temporally. So it is really practical to take into account the error-resilience effects in each step of the transmission system. In this paper, we describe a framework for video transmission over the packet-loss channel which features the coordinated operation of the H. 264 error resilience encoding, error concealment algorithms, transport-layer packetization and congestion control mechanisms. We analyze and design the key algorithms of the framework and the experimental results show that our approach works well in different channel conditions.关键词：end-to-end video transmission;congestion control;FEC protection2075|183|0更新时间：2024-05-07
- 摘要：To meet the requirement of mobile multimedia communication,the paper presents a new mobility model(MCM).MCM takes special requirements of mobile multimedia services into consideration,and is fit for real-world environment with obstacles.A routing algorithm,using MCM,is proposed for multimedia services in ad hoc networks.The algorithm is described in detail.This algorithm takes effects of obstacles into consideration,and is based on the basic routing protocols.By using standby nodes to provide alternate routing,it can not only obtain right route for transmission,but also avoid the link break.Compared with present routing algorithms,the algorithm is more adaptive to the transmission of mobile multimedia.2236|158|0更新时间：2024-05-07
- 摘要：Due to the real-time characteristic,live streaming applications attract more and more attentions.Most existing live streaming applications provide streaming clients with the same data at the same time,which do not match with each user's requirement.In this paper,a novel software architecture is proposed which can be used to implement a time-shifting live streaming system.Besides,this paper also proposes a novel algorithm to calculate the play time for the time-shifting system.At last,a system based on the proposed architecture and algorithm has been developed and deployed successfully in Shanghai Daning IPTV(internet-protocol television) systems.关键词：video streaming;Live Streaming;time-shifting;internet-protocol television(IPTV)2320|182|0更新时间：2024-05-07
- 摘要：For application of DVB Over IP,one important issue is about how to transmit compressed variable bit rate(VBR) MPEG-2 transport stream video.Transmitting compressed VBR video with traditional constant bit-rate(CBR)service requires a large buffer at the end.Another new transmission schemes called PCR-assist CBR which reduces the buffer requirement at the cost of higher transmission rate and low stability.To balance the transfer rate and the need for buffer in receiver,this paper presents an improved algorithm of transmitting transport streams called IPCBR which is based on PCBR.Experiments show that compared with traditional constant bit-rate service,the algorithm reduces the buffer requirement,provides high stability and high use of bandwidth as well as overcomes the problem of packet loss.Besides,the algorithm focuses on DVB over IP, so it has high practicability and also is valuable for developing new operation of Internet TV.2436|184|0更新时间：2024-05-07
- 摘要：Ultra-Wideband(UWB) is a radio technology to accomplish multimedia transmitting for HR-WPAN(high-rate wireless personal area network).Being modulated by a group of sharp pulse,UWB sends data through an ultra wide RF and shares in the spectrum with overlapping.UWB possesses excellent characteristics: high spectrum utilization ratio,ambition performance of anti multi-path attenuation,very low emission power and good system security.UWB provides the high-rate wireless connect scheme for consuming electronic devices,make the video connection and desktop application executing on common RF platform.Studying the development of UWB has realistic meaning that includes standardization,products,market and leading trend's technology.The paper provides an overview on UWB specifications,analyses the principle of MB-OFDM(multi-band orthogonal frequency division multiplexing) technology,and introduces the RF platform and its applications based on WiMedia UWB.关键词：ultra-wideband(UWB);wireless personal area network(WPAN);wireless multimedia;multiband orthogonal frequency division multiplexing(MB-OFDM)2283|190|0更新时间：2024-05-07
- 摘要：If error occurs when wavelet-coded images are transmitted over lossy packet networks, some part of the images will suffer from quality degradation. Traditional image reconstruction algorithms can be cataloged into space domain interpolation and wavelet domain estimation. In this paper, hybrid error concealment on both domains is presented, First, a simple reconstruction is carried out on wavelet domain by estimating the lost coefficients by its mean value of the surroundings in the low frequency subband. Second, we search for the match block of the kernel destroyed area according to the known correct wavelet coefficients. Finally, the image is re-transformed to wavelet domain after filtering, and the final reconstructed image is generated by combining both re-transformed coefficients and the original received coefficients. Experiments show that in most cases this method is better than the simple estimation by the mean value of low subband. PSNR is optimized by about 0.5 to 1 dB and the subjective image quality is also improved.关键词：wavelet transform;set partitioning in hierarchical trees;error concealment;hybrid estimation1986|180|0更新时间：2024-05-07
- 摘要：Amix control driving method of passive matrix OLED(PM2OLED) is described to drive high gray scale display. The method is based on mix control of current digital to analog converter(DAC) and digital space time modulation (DSTM). The low bit gray scale is driven by the DAC while the high bitgray scale is generated by DSTM. This method is applied to a 128×128 dots RGB PM2OLED panel which can drive 512 gray scales.关键词：PM-OLED;gray scale;space-time modulation;current DAC2485|198|0更新时间：2024-05-07
- 摘要：With the development of the grid technology, for quick response to the requirement of data application, the concept of data grid has appeared after computing grid. The query function is used very frequently in the database application, the same to the grid environment. It appears frequently that composing the database which distribute in various computer nodes to make a virtual database dynamically to finish a query because every database only includes a part of the information. This paper detailed research the question that how to finish the query and shorten the response time under the grid of heterogeneity of the nodes and the widely various communication speed between the nodes. It has important significance for the further research and development of grid database.关键词：computer supported cooperative work(CSCW);collaborative query;grid;database2379|179|0更新时间：2024-05-07
- 摘要：In this paper, we propose a concurrent control algorithm, which can realize the parallel and concurrent visiting of users, on the basis of the work regenerate of alterable period ; And then the consistency service and tracking service are raised to maintain the consistency of data source and client perform information.关键词：task list regenerating;service consistency;service tracking;grid technology2064|186|0更新时间：2024-05-07
- 摘要：The transmission of real-time multimedia is seriously affected by the mobility and highly dynamic topological of ad hoc networks,a clustering algorithm based on probability degree(PD) is proposed by using Markov process for solving the problem of instability and data losing in multimedia communication.Firstly,the algorithm forecasts the next time connectivity of the link between two random nodes based on that of current time,and then the node of the highest link connectivity probability is selected as the Cluster Head.The simulation results show that the number of clusters of PD is less than that of highest connectivity degree algorithm(HD),without overlapping nodes so that maintenance cost is effectively decreased.The number of cluster members shows minor differences,so it illustrates that PD algorithm has higher efficiency and no increase burden of Cluster Head,although the clustering number decreases.Finally,on the basis of clustering and considering the UDP protocols,a scheme of real-time multimedia communication in Ad hoc networks based on Probability Degree clustering is given.The multimedia communication is stable in ad hoc networks with the scheme and the problem of losing and out-of-sequence of data packet is solved.2644|176|0更新时间：2024-05-07
- 摘要：The workflow management system can improve enterprise's productivity and working efficiency.The workflow engine is the core of the workflow management system.This paper realizes a workflow engine based on Microsoft's cooperative platform: SharePoint,using XML Template with embedded C# code to define workflow,using agent service to realize the engine's logic components.Users can easily define their workflows and extend existing systems' interface by defining new port.This engine ensures the workflow management system's flexibility and extensibility.关键词：workflow engine;XML workflow template;windows sharepoint services/sharepoint portal server(WSS/SPS);agent service2778|183|0更新时间：2024-05-07
- 摘要：Composite discrete chaotic iterative system keeps all characteristics of each single chaotic iterative system and its dynamic behavior is more complicated. Because the key generated from composite discrete chaotic iterative system is independent identically distributed, encrypting the image by using the key and adaptive image scrambling algorithm can get a satisfied result. When the length of the entire key is more than 128 bits, the encryption system is robust under attack.关键词：image scramble;composite discrete chaotic iteration system;ergodicity;adaptive2329|194|0更新时间：2024-05-07
- 摘要：In this paper, a novel feature-based image watermarking scheme is proposed. Firstly, the Harris-Laplace detector is utilized to extracted feature points, which can survive a variety of attacks. Then, nonoverlapped disks around local feature points are defined adaptively according to the feature scales, Finally, several copies of the digital watermark are embedded into the nonoverlapped disks by comparing the DFT mid-frequency magnitudes. In watermark detection, the digital watermark can be extracted by using the maximum membership criterion. Experimental results show that the proposed scheme is not only invisible and robust against common signals processing such as median filtering, sharpening, noise adding, and JPEG compression, but also robust against the desynchronization attacks such as rotation, translation, scaling, row or column removal, shearing, and local random bend.关键词：image watermarking;desynchronization attack;feature point;local feature region2515|189|0更新时间：2024-05-07
- 关键词：AVS-M;intra prediction;mode decision;down-sampling2054|174|0更新时间：2024-05-07
- 摘要：In order to content with the constraint of available bandwidth variation,the sever needs to switch bitstreams dynamically in streaming applications.H.264/AVC supports SP-frame that enables high efficiency of switching among bitstreams of different qualities over larger bandwidth,and over little bandwidth fine granularity scalability video coding is supported by MPEG-4.In the paper,for make good use of the two advantage propose a seamless bitstream switching scheme that combines two tools and use self-adaptation bit-rate selection scheme for both high bandwidth variations of networks and low bandwidth variations,which is efficient for improving average PSNR from experience results.关键词：H.264/AVC;FGS;stream-switching;self-adaptation bit-rate selection2429|189|0更新时间：2024-05-07
- 摘要：To deal with the problem that Shanghai digital TV picture quality is poorer than traditional cable TV, picture qualities of several broadcasting taches are messured objectively. Lots of testing data are analyzed, and a conclusion is drawn that the encoding bandwith of encoders have great influnce on picture quality. Therefore, on the basis of current broadcasting system, a new method for increasing the encoding bandwith of encoders is discussed and put forward to improve the digital television picture quality.关键词：picture quality;objective evaluation;picture quality ratio(PQR);encoding rate2149|166|0更新时间：2024-05-07
- 摘要：The scalable extension of H. 264 is the newest work of developing joint standards for ISO/IEC and ITU. Now, this project is still in progress, and yet the main frame of the extension standard has been established. In order to make the ongoing standard known to people, in this paper a short introduction about the main frame of the H. 264 extension standard is provided first, with the mechanism of implementing spatial, temporal and quality scalability explained. Then the key techniques involved in inter-layer coding and fine grain quality scalable coding are analyzed in detail. Making use of the newest reference software JSVM5. 7, we carry out some comparisons and tests on performance and complexity, which verify that those techniques keep quite good coding efficiency together with satisfactory scalable performance.关键词：video coding;scalable;H.2642120|175|0更新时间：2024-05-07
- 摘要：When the compressed stereoscopic video stream generated by H. 264 coder is transmitted over the Internet, it is sensitive to packet loss. Due to the codec structure based on H. 264, a packet loss always causes the loss of an entire video frame. In such a case, a novel error concealment algorithm dealing with the loss of an entire right frame is proposed in this paper, Firstly it performs relativity analysis according to the coding scheme of stereoscopic video sequence, then obtains the prediction mode for every MB and conceals it. The experimental results show that the proposed algorithm can achieve better concealed quality with low complexity, so it is an efficient error concealment algorithm.关键词：stereoscopic video;loss of a whole right frame;error concealment;temporal relativity of prediction mode2623|187|0更新时间：2024-05-07
- 摘要：Comparing to other entropy coding standard,CABAC(context adaptive binary arithmetic coding) has more significant enhancement in compression.However,its encoding/decoding efficiency is low due to calculation complexity and costs in memory access.To deal with the "bottleneck" problem in decoding process,the article proposes efficient hardware architecture for CABAC decoder,including a new memory access mode,an optimizing decoding core and four concatenating decoding engines.The experimental results show that the decoding efficiency is greatly increased by the hardware architecture.关键词：H.264/AVC;context adaptive binary arithmetic coding(CABAC);model renewal;concatenate mode;self-adaptive2399|162|0更新时间：2024-05-07
- 摘要：In this paper, a new low complexity video coding method in camera array is proposed, based on the ROI-based Wyner-Ziv coding, The proposed method encodes each view independently at the senders, and performs joint decoding with side information interpolated from adjacent views at the receiver. Through comparing the quantized DCT coefficients, the proposed ROI-based Wyner-Ziv coding method can avoid to encoding the regions with little changes. Experimental results show that, the average encoding time of the proposed scheme is only 1/22 of the H. 264 P coding.关键词：video compression;dense camera array;Wyner-Ziv coding;low encoding complexity2340|192|0更新时间：2024-05-07
- 摘要：In order to improve the digital program production efficiency and achieve materials sharing, it is necessary to study networked HDTV NLE technologies including network flow control. This paper introduces a decoding scheme for a flow controllable networked high-definition non-linear editing. By taking advantage of resolution scalability and by means of progressive loading, the decoder can fetch the original video data in different transfer rate which is corresponding to the resolution levels included. Implementation and experiments on Mac OS X show that the method can effectively decrease the network traffic, and achieve favorable representation at client.关键词：JPEG2000;resolution scalable;QuickTime architecture2167|166|0更新时间：2024-05-07
- 摘要：Decision feedback equalizer(DFE) is an efficient scheme for suppressing intersymbol interference(ISI) in vestigial sideband(VSB) based digital TV(DTV) receivers.However,it suffers from error propagation(EP).This paper considers the use of soft decisions in mitigating EP in a DFE.An optimized soft decision algorithm using the hyperbolic tangent function in the decision device is proposed to improve performance over reducing EP.Furthermore,in order to speed up the EP simulation process,a simple but effective modification is made in the feedback tap weight updating process.Computer simulation results show that the proposed soft decision algorithm nearly meets the EP performance of ideal DFE,which is far better in performance compared to the erasure algorithm.关键词：decision feedback equalizer;error propagation;soft decision2360|169|0更新时间：2024-05-07
- 摘要：To achieve high performance and simplify the design,this paper presents the system design for de&re-multiplexing of MPEG-2 TS(transport stream) based on DM642.Compared to former methods,this design uses many DM642 internal hardware properties such as Video Port,PCI(peripheral component interconnect),EDMA(enhanced direct memory access) etc,by which the system performance is enhanced.The algorithm of PCR(program clock reference) correction based on VIC Port(voltage controlled crystal oscillator interpolated control port) is proposed which reduces the complexity of PCR correction.Experiments have proved that the max TS processing rate is 80 Mbps,which meets the application requirements.关键词：internet protocol television(IPTV);MPEG-2;De&Re-multiplex;program clock reference(PCR) correction;video port;VIC Port;peripheral component interconnect(PCI)2071|174|0更新时间：2024-05-07
- 摘要：Data compression is a key problem in the applications of hyperspectral images. To meet the demand, based on 2-D wavelet transform, this paper proposes a lossy compression method using band grouping and vector quantization. Every band of hyperspectral images is decomposed by biorthogonal filters and the coefficients are coded by Kronecker-Product Gain-Shape Vector Quantization. The experimental results have shown that the computational complexity is reduced. The high compression ratio is achieved and the spectral characteristics are preserved.关键词：compression;hyperspectral image;wavelet transform;vector quantization2371|165|0更新时间：2024-05-07
- 摘要：Moving object segmentation in the compressed domain is absolutely necessary for real-time applications.Due to the predominant compression efficiency,the emerging video coding standard H.264 is replacing MPEG-2/4 in many multimedia applications,but moving object segmentation in the H.264 compressed domain is rarely investigated until now.In this paper,we present a new approach to segment moving objects from the H.264 compressed domain.The motion vector(MV) field extracted from the H.264 compressed video is first normalized in both temporal and spatial domain,and the MV fields of several continuous frames are accumulated to enhance the salient motion.Then the global motion compensation is performed on the accumulated MV field,while the fast statistical region growing algorithm is exploited to segment it into different motion-homogenous regions.Finally,the orientation histogram of the MV field is exploited to determine the moving object regions.Experimental results for several MPEG-4 test sequences demonstrate the proposed approach can segment moving objects from the H.264 compressed domain in real time,and exhibit good segmentation quality.关键词：moving object segmentation;H. 264;compressed domain;motion vector field2384|170|0更新时间：2024-05-07
- 摘要：After JPEG double compressed,the DCT statistic of JPEG image will be changed,which is the focus in this paper.The distributions of DCT coefficients are changed with the double compression factors: Q_1 and Q_2.The difference of the distributions is analyzed in this paper.A new method-dithering pattern is proposed to detect double JPEG compression.Meanwhile,the necessary and sufficient conditions about dithering pattern are obtained.Experimental results show that this method is effective.关键词：JPEG double compressing;quality factor;dithering pattern3065|189|0更新时间：2024-05-07
- 摘要：In order to extract histogram information from the Compressed Video Stream rapidly, proposed a fast way to extract histogram from the H. 264 Compressed Video Stream, explaine the principle of this algorithm and describe its implementing procedure in detail. This algorithm is based on the information derived from the partially-decoded video bit stream, using the statistical method to get the histogram rapidly. Experimental results show that the presented algorithm can provide satisfactory results, and the computational complexity is significantly reduced. This algorithm can be used in the region of Shot Segmentation, Video Retrieval, and etc.关键词：histogram;H. 264;feature extraction;video retrieval;shot segmentation2244|174|0更新时间：2024-05-07
- 摘要：The new international video coding standard H. 264/AVC has significant improvements in coding efficiency and error robustness in comparison with the previous standards such as MPEG2, H. 263, MPEG4 part 2. But improved coding efficiency comes at the expense of adding complexity to coder/decoder. The research shows the conclusion that the calculation complexity of H. 264/AVC codec has several times as the previous standards, so as to get real time codec we must find high-effective optimization methods. The paper introduces the optimization solutions on software and hardware. The experimental outcomes are shown to achieve real time decoding with the optimized decoder.关键词：H.264/AVC;decoder;optimization;digital signal processing(DSP)2480|208|0更新时间：2024-05-07
- 摘要：The relationship of the coding bit rateRandρ, the percentage of zeros in a frame, plays an important role in ρ domain sourcemodeling rate contro.l TheR2D model is verified for Scalable Video Coding(SVC) at first. Then we studied the characteristic of the ρ2 Rcurve of pictures when encoding various test sequences with scalable video coding. We find that the model parameter of the pictures at the same temporal level have a close valve. Then an adaptive estimation scheme to estimate this model parameter is provided. Combining with its encoding feature, we propose an effective rate control scheme for the base layer of the scalable codec. We implement our algorithm in JSVM 1.0. The experimental results demonstrate that the outputbit stream of encoder is controlled accurately.关键词：rate control;scalable video coding(SVC);video compression2480|279|0更新时间：2024-05-07
- 摘要：This paper presents a high-performance FPGA hardware implementation of the H.264 transformation and quantization.The hardware prototype is composed of the whole processes from obtaining residual error to Macro-Block reconstruction,and it can be used as a co-processor of DSP to fulfill H.264 real-timing CODEC.Based on the characteristics of algorithms and data flow,the hardware prototype adopts pipeline strategy and time division multiplexing(TDM) technology,and utilizes FPGA dedicated resources reasonably,that enhances the performance of the hardware prototype greatly.The simulation results show that the design can satisfy the real-time constraints required by HDTV applications.关键词：H.264;integer transformation;scalable quantization;pipeline;time division multiplexing(TDM)3045|155|0更新时间：2024-05-07
- 摘要：H. 264/MPEG-4 AVC features flexible macroblock mode decision, which makes the number of data bits produced by encoding header information in H. 264 video stream vary irregularly and hard to be predicted. As H. 264 encoder reduces the data bits for transform coefficients effectively, the number of header bits takes a larger portion in the overall bits than that of any former video compression standard. Thus precise estimation of header bits can effectively improve the performance of the H. 264 rate control algorithm. In this paper, we apply the Kalman Filtering theory to improve the precision of estimating the number of the header bits at the frame layer, and incorporate the estimation model to frame layer rate control.关键词：H.264;rate control;header information;kalman filtering2115|141|0更新时间：2024-05-07
- 摘要：For improving accuracy,validating text is a key step of detecting text in video.The current approaches mostly based on experiential rules.The approaches are not adaptive,in condition of complex background,low resolution,varied font,size,color of text in video.For improving adaptability and accuracy of validating text,the application of two-dimension principal component analysis(2DPCA) for video frame processing is investigated and a novel 2DPCA and support vector machine(SVM) based approach for validating text in video is proposed.The approach has two steps of training and validating.Firstly,2DPCA is adopted to get the features of video image patches.Then,SVM is trained to validate and classify video image patches.The experimental results illustrate that the novel approach for validating text in video is more effective and costs less time than the other approaches,in condition of complex background,low resolution,varied font,size,color of text in video.关键词：text in video;text validation;2DPCA;support vector machine(SVM)2441|207|0更新时间：2024-05-07
- 摘要：This paper presents a method to measure speed of vehicles in video sequences conveniently and rapidly. Motion corner points are chosen to form a feature vector, and the image intensity is used as a feature matching function to measure inter-frame movement of the vehicle. With the present method, device limitations are alleviated and processing time reduced compared to traditional techniques.关键词：Harris corner detector;motion corner point;intensity correlation3124|167|0更新时间：2024-05-07
- 摘要：Text recognition in natural scenes has a promising future,but its application is limited by the technique of text detection and segmentation.To detect and segment text effectively,this paper proposes an approach for detecting and segmenting text from scene images by using Connected-Components' features.First,the image is decomposed into a list of Connected-Components(CCs) by Niblack algorithm.Then all the CCs' features are verified by 2-stage classification module which is composed by a cascade classifier and a SVM.Most of non-text CCs are filtered out by cascade classifier and the remaining CCs are further verified by SVM.The final outputs are binary images containing texts only.Experiments have been taken on lots of images,the precision is more than 90% and recall is more than 93%.关键词：cascade classifier;2-stage classification;text detection;text feature2824|178|0更新时间：2024-05-07
- 摘要：The scene segmentation is a high-level temporal video segment.This paper presents a method of scene segmentation based on semantics.At first,the video clips are segmented into shots and the shot key frames are extracted.Then the features of color histogram and MPEG-7 edge histogram of each key frame are computed and the feature vectors of shot key frames are formed.The support vector machines(SVM) are trained by these feature vectors and 7 binary classifiers in accordance with difference semantic concepts are constructed.These binary classifiers are used to classify the shot key frames of the video clips based on the features of the color and the texture and the semantics concepts of shot key frames can be obtained.The semantic concept vectors of shot key frames are formed by the semantic concepts contained in the key frames.The shot key frames are clustered by the semantic concept vectors and the video scene can be constructed.The shot select function is defined to extract the scene key frame based on the value of function.The experimental results shown that the recall and the precision of this algorithm are higher than those of the Hanjalic's method about 34.7% and 9.1%,respectively.关键词：scene;support vector machine(SVM);semantic;video4222|196|0更新时间：2024-05-07
- 摘要：Shape matching algorithm is widely used in many applications of the content-based retrieval, however, due to large data amount of the video stream and the computation of processing, the shape matching algorithm always become bottleneck in the real-time video retrieval. In this paper, we propose an improved algorithm for Hausdorff distance based on multi-resolution, supposed to be applied in the real-time vehicle comparison and recognition, the backward matching algorithm has a great optimization. Experimental resuh shows that the algorithm makes vehicle recognition more fast and accurate, expecially when the model image is big, this improved algorithm has a larger excellence.关键词：shape matching;Hausdorff distance;multi-resolution;vehicle recognition2851|174|0更新时间：2024-05-07
- 摘要：In order to give attention to both the smoothness of the boundary area near the seam and the coincidence of globe intensity in a resultant mosaic image simultaneously, an image mosaic method based on oriented vector field is proposed in this paper. With respect to the problem that it is very difficult for the existing image mosaic algorithms to be adaptive for the big gray difference between the to-be-mosaic images, an oriented vector field with the distributional characteristics of to-bemosaic object is set up at first. And then the resultant mosaic object is updated by interpolating and iterating under the guidance of the vector field. Finally, when the minimum gradient value near the seam is achieved, an ideal mosaic image with the effect of harmony in globe, and local smooth transition can be obtained. The experimental results demonstrate the effectiveness and adaptability of the presented algorithm in this paper.关键词：oriented vector field;image mosaic;iterative approximation2887|181|0更新时间：2024-05-07
- 摘要：Object segmentation and extraction are vital tasks in many issues of content-based video processing. A video object segmentation algorithm is proposed in this paper based on disparity analysis and threshold segmentation for stereoscopic sequences including overlapped multi-objects with global motion. An improved area-based method is firstly adopted for disparity estimation by accelerating the matching processing. Then, to segment different objects in the scene, iterative threshold segmentation and self-adaptive threshold segmentation are respectively performed on the images, and the objects are extracted at last. Experimental results show that the proposed algorithm is an effective object extraction method suitable for stereoscopic sequences with unitary global motion.关键词：stereoscopic video;object extraction;disparity estimation;threshold segmentation2567|178|0更新时间：2024-05-07
- 摘要：The freeform feature modeling was introduced in HUST-CAID.Classification and parameters were defined combining with the HUST-CAID system(computer aided industry design system developed by Harbin university of science and technology);users could intuitively design any curved surface using a set of suitable parameters provided by the system without concerning the lower layer design.If users want to modify the parameters,the system will correspondingly provide feedback automatically.In order to obtain the right graphics agree with the constraint,it is provided a new novel prototype-driven constraint solving algorithm.The simulation result in HUST-CAID shows that this novel algorithm simplified constraint solving and feature modeling greatly.关键词：feature modeling;freeform features;feature class specification;feature parameterization;constraint solving2536|198|0更新时间：2024-05-07
- 摘要：An HVS-based image hashing method incorporating a Watson's sensitivity matrix is proposed.The transform domain matrix composed of 8-by-8 block DCT coefficients of the image are multiplied by N matrices that are pseudo-randomly generated with a key,and divided by the periodically extended Watson matrix.By quantization,an N-bit image hash is obtained.Compared to some other hashing methods,the HVS-based hash has better robustness against JPEG compression and low-pass filtering.Since a key is used in the algorithm,the hash is hard to be forged.关键词：image hashing;human visual system(HVS);image authentication3556|184|0更新时间：2024-05-07
- 摘要：In this paper, a new image retrieval method based on the edge grid is proposed. Firstly, the color edge is extracted by using canny detection operator. Secondly, the whole color edge is divided to some local grids, and the color histogram and texture histogram for local grid are computed as image features. Finally, the similarity between color images is computed by using a combined feature index based on the color histogram and texture histogram for local grids. Experimental results show that the proposed image retrieval is more accurate and efficient in retrieving the user-lnterested images.关键词：image retrieval;color edge;local grid2571|171|0更新时间：2024-05-07
- 摘要：The omni-vision system for RoboCup middle-size league soccer robot-NuBot and its method for object recognition are introduced firstly in the paper,and then a simple front vision system is used to improve the accuracy of recognition of the ball in front,and meantime an easy and effective calibration method for front vision system is presented,and finally the realization mechanism for the two vision systems working together is introduced,in which the processing speed of robot's object recognition can be accelerated.The experimental result shows that the object recognition can be done successlly with the function of both vision systems.关键词：soccer robot;omni-vision;front vision;object recognition2513|186|0更新时间：2024-05-07
- 摘要：The ingredient analysis of ore microscope image is a challenging research area. To accomplish automatic recognition task on a kind of ore, this paper proposed an improved statistical hypothesis method for mesh texture ingredient recognition; and with Sobel edge detection, Skeleton Extraction, Hough Transformation another method is proposed on the recognition for needle like or striation texture ingredient. The experimental results show that the methods proposed in this paper are efficient.关键词：mineral texture;statistical hypothesis;edge detection;skeleton extraction;Hough transformation;image segmentation2377|196|0更新时间：2024-05-07
- 摘要：Movie films are often damaged by aging and multiple playing, which may cause some artifacts on the fihns, such as dust spots, dirt, blotches, film unsteadiness, line scratches, flicker, noises, color variations and blurs. Vertical scratch is one of the artifacts we can often see. To eliminate this artifact, we analyze the character of the line scratch and give a method for detection and removal of it. The proposed algorithm is based on the discrete binary wavelet decomposition, This transformation splits an image into approximation and detail coefficients. The locations of the scratches are gained through analyzing the horizontal and vertical components and using morphologic methods. We compare various algorithms that reconstruct the missing data in the region of the scratch, and choose to restore the scratch regions in the wavelet domain. The results show that the algorithm of scratch detection and removal in this paper is simple and effective.关键词：Digital Film Restoration;scratch detection;scratch removal;wavelet transformation2625|169|0更新时间：2024-05-07
- 摘要：The paper depicts mineral discrimination through image texture retrieval.The whole procedure goes like this: firstly dividing a large image into small window images,whose feature values are then extracted according to cooccurrence matrices and gray level run length matrices,with the limit of practical computation capability,only one single feature vector is applied in the classification.As we can see in the paper,a satisfying consequence can be reached when an appropriate threshold value can be provided.关键词：texture recognition;feature vector;similarity2185|194|0更新时间：2024-05-07
- 摘要：It can make effect for utilizing temporal-spatial coherence to improve the speed of collision detection.But at present,temporal-spatial coherence algorithm can only fit for the situation of two objects.It can't solve the problem of multi-object collision detection.Further more,if there are some fast-move objects in virtual environment,this algorithm also can't obtain good effect.In order to solve the two problems,we bring forward an improved algorithm which can be used in multi-object collision detection and assure the validity when objects move fast in virtual environment.关键词：temporal-spatial coherence;collision detection;bounding volume;list;space decomposition2176|184|0更新时间：2024-05-07
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An Adaptive Recognition Algorithm Based on Two-eye Computer Vision and Its Application in Monitoring
摘要：Two-eye computer vision algorithm uses the principle of Bionics. It gets the depth information of each pixel by two demarcated cameras. A new adaptive recognition algorithm based on two-eyes computer vision is presented in this paper. This algorithm makes use of the depth information of each pixel. Then it adopts the statistics method to model the scene and overcomes the gradual light change using time filter. It can also overcome the sudden light change with the characteristic of the depth algorithm. The video monitor antitype system using our algorithm can be set at more places than one camera system. It can set the alarm level according to the depth. Information, which can reduce the mistake ratio.关键词：two-eye computer vision;depth information;adaptive;light change;video monitoring2894|201|0更新时间：2024-05-07 - 摘要：Camera calibration is a key technology in computer vision,in which camera self-calibration technology is to compute the camera's intrinsic parameters from a series of images.Compared to traditional camera calibration methods,the process of self-calibration is simpler and more convenient for application.The self-calibration technology using Kruppa equation not only requires computing the fundamental matrix,but also computing the epipoles of images which are variable with the different images and will result in unstable computation results.GA algorithm is used to complete the self-calibration processing by estimating the new and simple Kruppa equations defined by Hartley.At last,the self-calibration problem is converted into the minimization of the cost function,so that the epipoles instability is eliminated and the calibration effect is improved.Experimental results show that the proposed method is simple and effective,and can become an versatile tool for camera calibration.关键词：camera self-calibration;Kruppa equations;fundamental matrix;genetic algorithm2648|171|0更新时间：2024-05-07
- 摘要：In order to avoid airplanes parking in the depot from crashing other moving airplanes, this paper proposed a method about position detection of airplane head based on image color character analysis. The method is used in the designing of intelligent security surveillance system for airplane depot toward the functioning of collision and striking warning. Firstly, the RGB image captured by the camera is transtormed into the HSI space. Then the red area, which is related to airplane head, is extracted by double thresholding of the saturation and hue components. And then the segmented image is post-processed with morphological operations to determine tile vertex of airplane head and the corresponding safe zone. Experimental results demonstrate that this method can detect the airplane head effictively and improve the performance of the classical surveillance system.关键词：color image segmentation;HSI color space;erode;dilate2375|173|0更新时间：2024-05-07
- 摘要：Purpose: In this paper,we accomplish image fusing of CT and MRI images using wavelet.Methods: As wavelet is of comfortable effect in image fusing,more and more researchers are working on it.And,in Matlab,there is a toolbox called Wavelet Toolbox 3.0,with which we can finish some image fusing simply.With some drawbacks,the toolbox works not so well with some kinds of image pairs,such as a picture of ct and a picture of pet,if the pet image is gray image instead of a counterfeit color image.Then the resulted image if of bad quality with low-lying effect.In order to achieve a good result of image fusing we should think about many aspects of it and realize them by program.Result: We strive to fulfill the program and compare the result to what we have got by toolbox.And the effect is comfortable.Conclusion: By wavelet toolbox,some simple medical image fusing can be accomplished.But with the development of technique of image fusing and the deepening of complexity of medical images,the process of image fusing would be more complex especially those images rooted from abdomen and chest.So more methods must be called for rather than toolboxes.关键词：image fusion;image registration;wavelet transform3047|200|0更新时间：2024-05-07
- 摘要：Disadvantages of traditional image compositing when applying to video image are analyzed, and a method of video image compositing in Y′CbCr space is propounded to composite video image fast. It also discusses the possibility and effectivity of implementing the video image compositing engine with Altivec on Power PC, and describes the implementation progress in details.关键词：Y′CbCr;video;image compositing;PowerPC;Altivec2098|195|0更新时间：2024-05-07
- 摘要：This paper addresses the problem of regional color transfer from source image to object image based on Gaussian mixture model(GMM). Instead of choosing RGB color space, images are processed in lαβcolor space, which minimizes correlation between the channels. Authors firstpick up color information of the source image to construct a reference color model by adopting GMM, then classify the color samples in object image according to the model and determine the color match between object image and source image. At last, new color transfer formulas are proposed for regional color transfer. Experimental results demonstrate that the proposed algorithm works very well not only on transferring color between two color images but also on colorizing gray image by color transfer from a color image.关键词：color transfer;Gaussian mixture model(GMM);image processing;architecture colored-drawing2641|219|0更新时间：2024-05-07
- 摘要：In this paper,DSF(definition,error sensitivity and objective fidelity),a new technique of color image quality measure has been proposed in which color image quality can be measured synthetically by calculating the objective fidelity,vision distortion and definition of a color image.The objective fidelity is a base for transverse comparison.While the vision distortion and definition is utilized for vertical evaluation.The great similarity among three frames of one image is taken into account fully and 3D-WDCT(three dimensional wide DCT) is used when the definition was calculated.Three frames,R,G and B,are integrated into one single mathematics model to be transformed.Against PSNR,this method will provide a better performance consistent with human visual characteristic.关键词：quality measure;objective fidelity;distortion sensitivity;definition;3D matrix transform2200|187|0更新时间：2024-05-07
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