最新刊期
卷 15 ， 期 1 ， 2010
- 摘要：based adaptive coding (CAC) is a class of new high-efficient entropy coding techniques for video compression. In this paper, a CAC-based scheme is presented to achieve realtime secure coding for digital video, and a secure coding chain is built based on CAC secure coder. Two kinds of secure coding operations, including context-based adaptive binary arithmetic secure coding (CABASC) and context-based adaptive variable length secure coding (CAVLSC), are given. The experimental results show that this scheme has significant improvement on security, real-time performance and flexibility of software implementation. These properties make it a sound foundation for further research on CAC secure coding.关键词：secure coding;video encryption;context-based adaptive binary arithmetic secure coding(CABASC);context-based adaptive variable length secure coding(CAVLSC)5903|888|0更新时间：2024-05-07
- 摘要：The current motion vector composition algorithms for reduced spatial resolution video transcoding does not consider the accuracy of input motion vectors. So the errors of these algorithms are rather big. In order to solve this problem, this paper proposes a motion vector composition algorithm based on the accuracy for reduced spatial resolution video transcoding. This algorithm includes two compositions. Firstly, it composes the input motion vectors by averaging them based on SAD. Secondly, it composes the neighboring motion vectors and composed motion vector in the first composition by selecting them based on rate distortion function. The simulation results show that the proposed algorithm reduces the error compared with the algorithms while maintaining the low complexity.3958|406|0更新时间：2024-05-07
- 摘要：In image watermarking, the watermark robustness to geometric transformations is still an open question. Using invariant image features to carry the watermark is an effective approach to address this problem. In this paper, a geometrically robust image watermarking algorithm using image normalization and wavelet moments is proposed. The geometrically invariant space is constructed by using image normalization. Some wavelet moments of the normalized image are selected, and their magnitudes are dither-modulated to embed the digital watermark. The watermarked image is obtained via reconstruction from the modified moments. Simulation results show that the hidden message can be decoded at low error rates, robust against image rotation, scaling and translation, and as well, a variety of other distortions such as lossy compression.关键词：image watermarking;geometric attacks;image normalization;wavelet moments;quantization4129|496|0更新时间：2024-05-07
- 摘要：In this paper, a new semi fragile watermarking scheme based on image content for tampering localization and recovery is proposed. The authentication watermark is embedded in the SVs (singular values) with an adaptive quantized method within the domain of nonsubsampled contourlet transform (NSCT). This method can improve the tampering localization capability without causing noticeable artifacts and can distinguish involuntary modification from vicious attacks. The recovery watermarking is achieved by dividing the original image, scrambling, encoding and encrypting, at last handing on the third party in which zero watermarking technique is used. The results of the experiment show that the proposed scheme can detect and localize the tamper, as well as can recover the tamper image when it undergoes JPEG compression.关键词：fragile watermarking;tamper localization;image recovery;nonsubsampled contourlet transform;chaos4450|452|0更新时间：2024-05-07
- 摘要：Many of the current methods for image denoising and restoration utilize total variation (TV) regularization to preserve its beneficial edge properties. However a particular caveat of TV regularization is the staircasing phenomenon in recovered images. A new blind restoration model based on a fourth order partial differential equation (PDE) is proposed for image restoration, which improved the Chan and Wongs TV model. The new method is to introduce fourth order norm into the energy function instead of TV norm, to overcoming the staircasing in reconstructions form TV regularization. The result of experiment shows that this restoration model is more visible.关键词：image blind restoration;TV regularization;fourth-order PDE;staircasing phenomenon3930|407|0更新时间：2024-05-07
- 摘要：Blind watermark extraction can be fulfilled without referring to the original host image. Therefore it has much prospective applications in the fields of information hiding and copyright protection. Based on blocking Discrete Cosine Transform (DCT) and blocking Discrete Wavelet Transform (DWT), the proposed blind watermarking algorithm uses an embedding strategy of adaptively selecting either relationship embedding or quantization embedding. The relationship embedding comes from the observation that both the magnitudes of coefficients concerned in the relationship usually have the same change trend when the image is attacked. This strategy remarkably improves the robustness of watermark extraction. In addition, dither modulation is used in quantization embedding, by which the tradeoff between transparency and robustness of watermarking can be easily adjusted. Simulation results show that the algorithm is fairly robust against the attacks such as noise, filtering, compression, and contrast enhancement, and it maintains satisfying transparency.关键词：digital watermarking;blind watermarking;relationship embedding;quantization embedding;DCT;DWT3839|412|0更新时间：2024-05-07
- 摘要：To deal with the drawbacks of differential energy watermarking(DEW) algorithm such as its poor transparence, low capacity and weak robustness, we propose a blind video watermarking scheme related to differential energy modulation(DEM). It chooses the embedded regions of a quantized block，and labels a hiding bit by dithering differential energy between the horizontal and the vertical sub regions of that block, with an adaptive quantized index modulation(QIM) method. To assure transparence and robustness, the embedded error is spread over 10 biggest coefficients of each host block. The perceptual quality and the length of an original sequence could also be kept unchanged owing to its similitude codeword replacement. Experiments demonstrate that DEM is superior to DEW in the performance of transparence, capacity, robustness and rate maintenance. At the same time it achieves a better robustness than QIM, for QIM carries one bit in one coefficient, whereas DEM embeds one bit in one region.关键词：differential energy modulation (DEM);error resilience;rate maintenance;quantized index modulation (QIM);differential energy watermarking (DEW)4184|346|0更新时间：2024-05-07
- 摘要：The conversion should be completed from the YUV color space to RGB color space in video processing. In this paper, by analyzing the YUV format and RGB format conversion algorithm, floating point operations is replaced by integer operations and divisible by 256 corresponds to eight right shift operation to increase the speed of calculation. Combine intel single instruction, multiple data extension SSE2 instruction set technology optimization algorithm, the efficiency of the different digital video format conversion is significantly improved. Experiments prove that SSE2 technology can increase by 25 times the computational speed and has a good application in the video processing.关键词：Color Space Conversion;YUV;RGB;SSE24857|417|0更新时间：2024-05-07
- 摘要：Image inpainting techniques based on texture synthesis can be used to remove large objects from digital images. However, these algorithms have high time complexity. To improve the matching technology in inpainting, this paper presents a efficient algorithm that is based on average gray value. Average gray values of texture blocks are calculated to avoid complex calculation of SSD (sum of squared differences). Then in the matching process, most blocks are rapidly eliminated by comparing their average gray values with threshold control. The result shows that the algorithm obtains both real time performance and high quality result. The proposed algorithm has general applicability in texture synthesis and image inpainting.关键词：image inpainting;texture synthesis;average gray value6819|654|0更新时间：2024-05-07
- 摘要：As one of the most typical nonlinear filters, weighted median filter has considerable filter behavior by assigning weights. But each pixel has only one weight in the traditional weighted median filter. Correlations between pixel and other pixels under the filtering template are not considered. A novel weighted median filter model is proposed here where the weights correspond to these correlations. In order to keep stability when filtering on rotated and reversed images, symmetry of the correlations is utilized and can reduce the model complexity. Differential evolution algorithm is adopted for the weights optimization. Experiments about weights optimization show that this rotation invariant model exhibits faster convergence characteristics. Impulsive noise removal both on different gray images and color images show that it preserves better properties of edges or details, and has efficient noise attenuation and chromaticity retention.关键词：weighted median filter;rotation invariant;gray image denoising;color image denoising;differential evolution4428|393|0更新时间：2024-05-07
- 摘要：A color image segmentation algorithm by integrating watershed with automatic seeded region growing is proposed in this paper Anisotropic diffusion based on edge confidence is used for image smoothing preprocessing, which can eliminate noise, while maintain image edge information, and so that the watersheds over segmentation problem is effectively solved The algorithm of automatic seeded region selection based on the mean hue difference is designed to make seeded region growing based on the regions similarity of mean hue value and mean saturation value Furthermore, an algorithm of small region removing is designed to removing the small regionAs a result, the color image segmentation is efficiently realized The experimental results demonstrate that this algorithm is simple and fast, can obtain better segmentation results compared with other algorithms关键词：watershed;automatic seeded region growing;small region removing;anisotropic diffusion;color image5814|669|0更新时间：2024-05-07
- 摘要：Chan Vese (CV) model, which has good ability to handle the blurry boundary and complex topological structures in images, has been widely used in image segmentations. However, the MR image which has intensity inhomogeneity cannot be segmented accurately by the CV model. And it needs computing all the data of the image during the iterative course. Arming at these disabilities, a fast method of CV model based on statistics in local regions is proposed. First, by calculating the statistics in local regions, Bayesian posterior probabilities that decide which class the pixels belong to are obtained, which are the foundations of the evolution of curve. In this way, the MR images can be segmented accurately. And then two lists are set for storing joint points inside and outside of the curve, and it only need to update the two lists to evolve the curve. By this method, it not only saves lots of time but also preserves the advantages of level set methods, such as the automatic handling of topological changes.关键词：CV model;Bayesian posterior probabilities;level set;MR image segmentation3827|381|0更新时间：2024-05-07
- 摘要：In order to improve the stability and generality of image segmentation, a new method based on the dynamic multi-cue integration is presented in this paper. It fuses color, texture, spatial and edge information by the construction of a conditional random field for image segmentation. Besides, in the course of interactive image segmentation, the proposed method is able to take full advantage of the user labeled information about the foreground and background, and builds a certain standard to measure the reliability of established probability distribution, with which to assemble the energy terms in the conditional random field. This makes the related energy terms fusing dynamically in accordance with the inner property of the image,and improves the segmentation power of the model. The experimental results demonstrate that the proposed method performs steadily and works well on various natural images.关键词：interactive image segmentation;conditional random fields;dynamic integration;Jensen Shannon divergence;graph cut4237|462|0更新时间：2024-05-07
- 摘要：Mean shift can make rapidly optimal matching during target tracking. But Mean shift algorithm doesnt use the targets motion direction and speed information. When targets moving speed is so fast that its easily fails to track the target accurately. We proposed a new target tracking algorithm combining motion vector analysis with Mean shift algorithm. By statistical analysis of the motion vector, we adjust the central point of the motion candidate region of Mean shift, which makes the starting position for search more close to the centre of the actual objective. New method not only improves the accuracy of fast moving tracking, but also reduces the iterative times during the center searching.5669|509|0更新时间：2024-05-07
- 摘要：For small target tracking in infrared (IR) image sequences, a particle filter algorithm based on feature fusion is presented with the analysis of the characters of small IR targets. Taking the advantage of particle filter of supporting target feature fusion method, this algorithm combines the gray feature with fractal feature, and then uses the fusion results to calculate the particle weights, which greatly improves the robustness of the tracking algorithm. The experimental results show that the presented method is more accurate and effective for small IR target tracking in infrared image sequences than the traditional particle filter method.关键词：small IR target tracking;particle filter;feature fusion;gray histogram;fractal dimension4356|709|0更新时间：2024-05-07
- 摘要：In this paper, an expression recognition algorithm based on image reconstruction is proposed. Firstly, manifolds of different subjects were obtained singly using the Lipschitz Embedding algorithm. Mapping between manifold vectors and image vectors was established. Then, the coordinates of testing image in manifold space was confirmed by nonlinear reconstructing. Finally, expression images were reconstructed according to projecting vectors of testing image on manifold paths and expression recognition was accomplished. The algorithm solves the problem that expression manifolds overlap with one another. It is robust to the variety of expression intensity. The experiments in Cohn-Kanade and CMU-AMP face database show the algorithm has better expression recognition accuracy.关键词：Lipschitz embedding;nonlinear mapping;image reconstruction;expression recognition3945|394|0更新时间：2024-05-07
- 摘要：Boundary extraction is the foundation of image recognition A method of B-spline active contours boundary extraction based on conjugate gradient vector is presented With human machine interface, it gives a B-spline curve which is close to and similar to the objective edge in shape and location Rather than evolving deformable curve with every pixel on the curve in conventional method, the proposed method evolves the curve with controlled node points which are much less than pixel points in numbers, so computational cost should be reducedThen, an additional conjugate gradient vector force is added on the evolution curve in the gradient vector field, it can make the active contours convergence to the desired edge quickly The experimental result shows that the proposed method can solve deep concave problems and is efficient in image boundary extraction关键词：active contours model;B-spline curve;conjugate gradient;gradient vector flow4073|438|0更新时间：2024-05-07
- 摘要：Hough transform (HT) is a typical algorithm used for the detection of lines or line segments. The generalized HT can be used for detection of complex 2D polygons, but it needs voting in 3 or more dimensions. This results in the need of large memory space and long computing time. And some of its variations, in which the derivative/gradient information of the image is needed, are sensitive to noise in images, so that the robustness of the methods decreases. This paper presents a unified approach based on Hough Transform for quick detection of planar rectangles and circles. The presented approach introduces a geometrical invariant — the Shape Angle Dα, and makes good use of geometric properties of polygons for roughly classifying shapes of closed edges that are detected by Canny detector. It does not need any derivative/gradient information of images but simple computation and only 1D or 2D votes to improve the robustness and speed up the computation of the algorithm presented. Finally, it is shown by the experiments that this approach can be used for detecting various planar regular polygons, and it is not only quick but also accurate.关键词：image recognition;Hough transform;planar regular figure;geometric feature5315|561|0更新时间：2024-05-07
- 摘要：Dayside corona aurora is the typical ionosphere track generated by the interaction of solar wind and magnetosphere, and the detection of corona aurora is significant to the study of space weather activity. According to the appearance feature of corona aurora, an algorithm based on static image classification is proposed to detect dayside corona aurora. At first, Gabor features are extracted from original aurora images. Then, supervised K-means clustering is proposed to select training samples for the sake of their diversity and representative. AdaBoost algorithm is used to select features and build cascade classifiers to implement the detection of dayside corona aurora. The experimental results on the real aurora image database from Chinese Arctic YellowRiver Station illustrate the effectiveness of the proposed algorithm.关键词：dayside corona aurora;Gabor features;Adaboost algorithm;k-means clustering3804|416|0更新时间：2024-05-07
- 摘要：A robust shape matching method is presented in this paper. An area based parameterization technique is designed for shape resampling. Then the parameterized summation invariant (PSI) is generated based on the resampled shape and summation invariant (SI). PSI which uses local parts of a shape to characterize the shape and can be calculated via integral operation is affine invariant and robust against noise. In order to improve the robustness of shape matching, prior information of PSI is analyzed to define a notion of distance between shapes based on feature regulating. The proposed distance measure can be implemented by dynamic programming. Experimental results show that the proposed method is valid.关键词：shape matching;affine invariant;feature regulating;dynamic programming3613|486|0更新时间：2024-05-07
- 摘要：In order to describe image complexity in a better way, this paper discussed the description principle of traditional complexity from the perspective of composition theory, and introduced it to the domain of image complexity. Firstly, the authors discussed traditional calculation method of complexity and analyzed its limitation, which is based on a sequence of tests. Secondly, the authors proposed a novel approach to image complexity description, which adopts gray level, gray spatial distribution, and object quantity, including information entropy, texture, edge, and other relevant factors. Finally, the complexity of several different remote sensing images was tested. Results show that this description way can be used to reflect the overall image complexity, achieving the purpose of quantitative and quantitative comparisons between different images.关键词：the constitution theory;complexity;image complexity;automatic target recognition4684|411|0更新时间：2024-05-07
- 摘要：This paper analyzes the application of an optimized method in the modeling and animation of 3D complex forestry scenarios of peach and Chinese white poplar. The paper divides the forestry scenarios into close views and distant views respectively according to different visual impacts, and applies different modeling and animation procedures. The particle system is employed in the close views while the methods of multi-layer circle cylinder background and the plane mapping constrains model are adopted for the distant views. The complex 3D forestry scenarios created have vivid close views and excellent visual effects in distant views. The method well accomplishes the simplification of models and the optimization of visual effects.关键词：close view;distant view;particle system;multi layer circle cylinder background;constraint3612|495|0更新时间：2024-05-07
- 摘要：An improved algorithm based on correcting triangle shape is presented to improve accuracy and stability of computing vertex normal of triangular meshes. Firstly, five representational algorithms are analyzed by comparing their weighting characteristics. Following that, a quantitative assessment parameter to estimate the quality of triangle shape is proposed and demonstrated in theory, and then we put forward an improved equation to amend the influence of triangle shape. Finally. the article tests all algorithms with regular and irregular triangular meshes of quadratic surfaces for evaluating the algorithms accuracy and stability. Experimental results demonstrate the improved approach is effective.关键词：shape correction;triangular mesh;vertex normal;error analysis3686|385|0更新时间：2024-05-07
- 摘要：Volumetric 3D display(V3D) is one of the newest solutions in the true 3D display field. Its primary advantages are direct, group and all point of viewing. In order to display a complex 3D image in real space, a passive rotating sweep V3D system based on digital micro mirror device(DMD) is studied and realized, in which a sequence of two dimensional slices of a 3D image are projected onto a rotating screen by DMD. Due to the vision persistence of human eyes, the image is reconstructed in the cylindrical volume swept out by the screen. The composition and principle of the system are analyzed, while the hardware design and software algorithms of the image space, voxel activation device and V3D engine are discussed in detail. The two V3D experiments with models of tri cone and plane indicate that users can observe solid 3D images with clear profiles in the scope of 360 degree, and the result validates the design and shows that the system can display complicated 3D images in real space.关键词：digital micro mirror device(DMD);volumetric 3D display;rotating sweep;image space3442|1175|0更新时间：2024-05-07
- 摘要：A novel remote sensing image retrieval method based on artificial immune system (AIS) is proposed in this paper. Based on the relevance feedback technology and the immune mechanism, clonal selection algorithm is used to learn and memorize the user feedback image feature, the recognition of customers' semantic target for system is improved. Experimental results show that this approach can recognize the user feedback information efficiently and improve the retrieval accuracy.关键词：artificial immune system;remote sensing image retrieval;relevance feedback;clonal selection4443|423|0更新时间：2024-05-07
- 摘要：In wireless multimedia sensor networks (WMSN), sensor devices are constrained in terms of power, processing, memory and bandwidth capability. Low complexity video processing technique is highly desired to encode and transmit large numbers of video data. Based on the information from multi modal sensors which monitor the same scene, a new framework of distributed video processing system for WMSN is presented. A group of pictures (GOP) partition algorithm based on multi modal data and multi view is also put forward. In the decoder, considering the temporal correlation between adjacent frames from single view, temporal side information is generated. Multi view side information is acquired by using spatial correlation among the frames from adjacent video sensors. In order to improve the prediction accuracy and reliability, a mechanism to fusion and select two kinds of side information is provided. The validity and advantage of the proposed method are verified through simulations.关键词：wireless multimedia sensor networks;distributed video coding;multi modal sensors;group of pictures(GOP);information fusion;side information4672|338|0更新时间：2024-05-07
- 摘要：Nonlinear unmixing of mixed pixels in remote sensing imagery are commonly conducted with neural networks (NN) models, which, however, lacks physically based interpretation as linear models. This paper the difficulties of knowing patterns of pixel mixture and error distribution to some extent. This paper proposes to use mean square error, bivariate distribution function, confidential error, and synthetically mixture complexity techniques to analyze and evaluate the pixel mixture, which can provide insights in some features of nonlinear mixture models. Experiment with MODIS associated with ETM+ data demonstrates that the visualized method can obtain the decomposition characterization of PPLN model efficiently. In addition, visualized assessment shows that PPLN provides higher accuracy compared with the BP neural network. The overall unmixing error decreases from 0.182 8 to 0.171 7 in terms of RMSE, improved by 6.5%. The experiment also demonstrates that urban and sparse vegetation are the potential occurrence places where pixels are severely mixed.关键词：Nonlinear unmixing;visualization;mixture pixel;error distribution5013|293|0更新时间：2024-05-07
- 摘要：Image registration is an important step of image fusion, change detection and target recognition in remote-sensing applications. As a similarity measure, mutual information has become a hot topic in image processing, for its advantages of no pre-processing, robustness and a high degree of automation. But with the increasing of image size in remote-sensing, high computing complexity of image registration algorithm makes that traditional single-processor computing mode could not meet the requirement of real-time processing in some applications. Based on the experimental analysis of corresponding serial algorithm, a parallel region-based registration algorithm based on mutual information for remote-sensing images is proposed. Strategy of data partition and parallel computing method of mutual information are given. To avoid data communication, some techniques like redundant data partition on boundary and reducing on binary-tree are used. Then, a quantitative analysis of computing difficulty is given. The experimental results show that the proposed parallel algorithm has good scalability and applicability.关键词：mutual information;remote sensing image processing;region-based registration;parallel algorithm5293|354|0更新时间：2024-05-07
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