最新刊期
卷 11 ， 期 8 ， 2006
- 摘要：The multimedia applications in a multiresolution environment, such as progressive transmission of image,image database browsing, etc. , arise scalable image coding algorithm. This paper first explains the concepts of all kinds of scalable image coding, and gives an analyse for the scalable image coding algorithms in JPEG and JPEG-2000. Secondly, an overview of major methods already used or under investigation for scalable image coding based on Wavelet, DCT and Matching Pursuit with the scalable coding tools and methods is introduced, and the decoder performance comparison among the three kinds of scalable coding is given. In addition, the trend of the three kinds of scalable coding and their extension in video scalable coding is discussed. Finally, the future development of image coding is also analyzed and conjectured in the paper.关键词：image;scalable coding;DCT;wavelet;matching pursuit2798|218|0更新时间：2024-05-07
- 摘要：Based on homogeneous coordinates, this paper presents a convenient algorithm for approximate degree reduction of NURBS and rational Bezier curves and surfaces. In homogeneous coordinates, the difference of the low degree curve/ surface and high degree curve/surface is minimized. The problem of approximate multi-degree reduction of rational curves and surfaces is transformed into quadratic programming. Error estimate is presented. Experimental results show that this algorithm is very efficient.关键词：NURBS;rational Bezier;degree reduction;quadratic programming2326|200|0更新时间：2024-05-07
- 摘要：The Hilbert curve is a way of mapping the multidimensional space into the one-dimensional space. Such mappings are of interest in a number of application domains including image processing and the indexing of multidimensional data. However, little has been discussed on its high dimensional algorithms due to the complexity. In this paper, a novel algorithm is presented for generating an N-dimensional Hilbert curve, which analyzes a Hilbert curve from bottom to top, based on a static evolvement rule table. The experimental results show that our method is easier to implement and faster in computation than other methods.4365|204|0更新时间：2024-05-07
- 摘要：With the security problem of image information as research background,this paper introduces the Advanced Encryption Standard(AES): Rijndael algorithm.Base on the symmetry block cipher algorithm,a method for scrambling and restoring digital images is proposed,which uses the AES algorithm under the control of secret key.This method is safe as well as simple.A simulation shows the effect of image scrambling,and it is analyzed by comparison of histograms.The results show that: this method can reach preferable effect of encryption and decryption,and further more,it's easy to realize.关键词：advanced encryption standard(AES);digital image;digital image scrambling;information security2641|191|0更新时间：2024-05-07
- 摘要：Based on spread spectrum communications,the approach concerns mainly a series of techniques: the substitution of DCT of 2D in frequency domain of the owner image,the use of selection-and-group tactics conducted by means of JND threshold of gray-image and the multiple-based work underlying DCT frequency domain of the owner image,the classification of embedded watermarking with AC of intermediate frequency,the performance at random on AC of high-low frequency that embedded,and the realization of digital blind watermarking of multiple gray watermarking in order to transmit it by the mode of carrier wave.This algorithm evaluates the capacity of the digital watermarking and extracts the digital watermarking without the original watermark and the owner image.The experimental results proves that the algorithm is of good robustness and renitency for the procedures,like filtering,adding noise,clipping,JPEG compression.关键词：digital blind watermarking;spread spectrum;DCT frequency domain;AC;Multiple-based;JND threshold.3215|220|0更新时间：2024-05-07
- 摘要：More and more people pay attention to the technology of information hiding because of the development of Internet and digital work.In the paper,a new scrambling method is introduced after analyzing the advantages and disadvantages of some other information hiding methods.It modifies the form of transformation matrix that is used to scramble the position and gray level of each pixel.This method changes not only the texture but also the statistical property of an image.Compared with other approaches,it has the following advantages: It improves the secrecy property of an image and reduces the attacker's notice;It has the less calculated capacity.Simulations show that it is practicable.关键词：position scrambling;gray level scrambling;information hiding2666|221|0更新时间：2024-05-07
- 摘要：Linear pixel unmixing is a straightforward and efficient approach to the spectral decomposition of hyperspectral remotely sensed scenes,which involves only a single pixel with the same mixing proportions.In this paper we develop a method of selective endmembers for pixel unmixing.The proposed algorithm compares pixel spectral with endmember spectral and take the neighboring pixel into account when selecting the endmember matrix(EM).Experimental results show that the selective endmember algorithm achieves improvement over conventional linear algorithms.关键词：selective endmembers;mixed pixel;remote sensing;image classification3804|194|0更新时间：2024-05-07
- 摘要：With the development of high resolution synthetic aperture radar(SAR), great quantity of complex data are generated by the real time SAR image processorwhich makes effective complex image compression algorithm necessary to release the burden of the capacity of the downlink and the storage system. Complex image compression can reduce the data amount. However the compression algorithm for the SAR complex images is specia,l which needs to keep the phase preserved. Generally speaking, the optical image compression algorithm isn’t suitable for SAR complex images. The coherent speckle noise and the random phase of SAR complex images make compression difficult. By examining the characteristic of complex image data, this paper presents an efficient compression method based on block adaptive quantization(BAQ) after removalof frequency redundancy. The BAQ is adapted to the high dynamic range ofSAR complex images and reduces the quantization error. The calibrations of SAR image such as resolution in azimuth and range, integrated side lobe ratio and peek to side lobe ratio, interference images etc. indicate that ourmethod is effective for the fidelity of SAR images’magnitude and phase under the compression ratio of 16∶1. What ismore, ithas the preference of low complexity and easy implementation in real time system.关键词：SAR(synthesize aperture radar);complex image;block adaptive quantization(BAQ);arithmetic codec3357|205|0更新时间：2024-05-07
- 摘要：The geolocation algorithm of Space borne Synthetic Aperture Radar(SAR) is the fundamental for developing geocoded ellipsoid correction(GEC) and geocoded terrain correction(GTC) algorithm, so it is very important to develop high accuracy geo location algorithm for the application of SAR imagery. After detailed investigation of the currently available SAR geo location algorithms, a new geo location methodology AIRGM (Analysis and Iterating Routes Based Geolocation Method) was developed. AIRGM was developed from the pure analysis geo location method (AGM) by integrating numerical iteration routes into AGM. So this new geo locationmethodology has advantages ofboth pure analysis method(efficient) and pure numericalmethod(high geolocation accuracy). Applying the three geolocation methods to one scene of ERS22 SAR SLC imagery, the geolocation accuracy of AIRGM was compared with the other two published geolocation methodologies(ASF and AGM) through two kinds of validation method. The first validation method takes the geographic coordinate of the four image corner points provided with SAR data as reference, while the second method takes 14 ground control points(GCPs) collected from 1∶50 000 geographicalmap sheets as reference. Ithas been shown that the new geo location algorithm can achieve higher geo location accuracy, and the efficiency of geo location processing ismuch higher than the pure numerical geolocation method(ASF), which is built up on many iteration routes.关键词：space-borne SAR;RD geo-location model;direct geo-location;geocoding2775|195|0更新时间：2024-05-07
- 摘要：The contour tracking is one of the important steps in reverse engineering based on industrial computed tomography. In this paper, the singular pixels of CT slice contour after edge detection, such as discontinuity, redundant, double pixels, are analyzed and the contour tracking algorithm combined eight neighborhood calculation with five neighborhood is presented, which removes the singular pixels effectively and gives a close contour with single-pixel connection. It is shown by the experiments of a vehicle engine that the contour can be obtained exactly and the method is practical.关键词：reverse engineering;industrial CT;contour tracking;image processing2346|173|0更新时间：2024-05-07
- 摘要：A fuzzy adaptive Gaussian model is presented in this paper. The method which is based on the fuzzy characteristic of image is employed to detect the moving object in the industrial field. Firstly three fuzzy Gaussian models under three main background states are set up. Then some independent, relatively still regions in the image are chosen to replace the whole background image in order to reduce the heavy calculation in the on-line detecting. At last, the suitable Fuzzy Gaussian background model matching current background is determined by fuzzy recognition. The method can not only be adaptive to environmental transformations but also satisfy the requirement of real-time detecting in the industrial field.关键词：moving object detecting;Gaussian background model;adaptive;fuzzy recognition2353|190|0更新时间：2024-05-07
- 摘要：A novel method is presented to estimate the distance between the railway and the poles alone the railway in one image based on the edge extraction of the poles. It has three main parts which are poles and the railway detection, poles classification and distance estimation. In the image with distortion and complex background, how to effectively and accurately detect the edges of the target is a crucial and difficult issue for image understanding and pattern recognition. This paper presents a robust straight-line extraction algorithm to solve this problem. This algorithm can extract the exact straight line edges of interesting target in the image with distortion and the complexity of scenes based on a fuzzy threshold and line fitting. The three main steps of the algorithm are edge detection, corner detection and the straight-line fitting based on fuzzy threshold method. The experimental results on real images demonstrate that the straight-line extraction algorithm we proposed is superiorly accurate and effective, and the distance estimation method is effective.关键词：straight-line extraction;straight-line fitting;fuzzy threshold;target detection;partition recognition;Kalman filter2475|198|0更新时间：2024-05-07
- 摘要：This paper presents an intelligent method for detection of traffic signs. Which uses a particular color and shape for the detection of traffic signs. Red color and down triangle shape traffic sign is taken as an example, explain this method. This method is mainly carried out in four steps. First, convert RGB color space to HIS color space, and extract pixels with red color. Then perform LOG mask operation on the pixels got from step 1, for the detection of edges. By using neural network, we determine the angle pixels, and at the same time, we also determine on which specific angle the pixel is. And finally we detect the traffic sign by using the information of shape. We used 20 different images from different scenes to test this method, and the percentage of correctness is 100%. The experimental results reveals the good robustness, high speed , accurate detection rate of the presented method.关键词：triangle traffic sign;traffic sign recognition(TSR);image detection;neural network;computer vision3642|248|0更新时间：2024-05-07
- 摘要：In magnetic resonance imaging,the number of phase-encoded signals is often reduced to minimize the acquisition time.The partial k-space data lead to the famous Gibbs artifact with Fourier transform method.The Gegenbauer reconstruction method has been shown to effectively eliminate the Gibbs artifact and restore high resolution.However,the disadvantages of using the Gegenbauer method are more computational time,and more constrains,where parameters must satisfy certain conditions.The paper shows that the inverse polynomial reconstruction method(IPRM) based on Chebyshev polynomials effectively improves the Gegenbauer method and reduces reconstruction error.In this paper,we discuss IPRM based on Chebyshev polynomials and experimental results.The proposed method is verified with experiments of artifact removal.关键词：magnetic resonance imaging;Gibbs ringing artifact;partial k-space data;IPRM3684|166|0更新时间：2024-05-07
- 摘要：As a vital branch in the study of biometrics-based technology, identification and verification by palm print has been a striking evidence for prior disease diagnosis and personal recognition, given its remarkable advantages like simplicity and stablility, etc. Especially, the extraction process of principle-line feature plays a key role. This paper presents a new approach to extract this novel characteristic. Unlike other traditional methods, its step is inherently simple and convenient using regular scanner. After the pre-process and alignment, we extract four spatial directional template and reach high convergence by adopting Symlet wavelets transformation method, and a series of morphological operations derived from ASF are utilized. Finally we use regression analysis and image fusion to eliminate divergence and disconnectedness in our result region, and successfully extract principle-line from numerous palm-lines. The experimental results with a large collection of different images showed its advantages compared with former work, and also illustrated its strong robustness, and provide effective and accurate statistics to clinical diagnosis, classification and encoding work at a later stage.关键词：palm print;orientation projection method;Symlets wavelet;Plessey operators;ASF(alternating sequential filter);robust regression;image fusion3221|212|0更新时间：2024-05-07
- 摘要：In this paper we propose a method for making panoramas from video sequence taken by moving cameras.We mainly describe the case where the camera is moving and there are large-area non-rigid moving objects in the scene.But the method also works well when there are no moving objects in videos.Affine model is used to describe the camera motion.To calculate the parameters in affine model,we use feature points matching method.Correlation method is used to match feature points in frames,but correlation method can only give a coarse result which may include some bad matching.To ensure the precision of the motion parameters,RANSAC is used to pick out bad matching.Project frames with motion parameters,and the intersection of two subtraction results of neighbor frames will give the moving object area.Last we can calculate the panorama image.Results given by this method are provided in this paper,and we compare them with other people's results.It proves that our method can make panoramas with high quality.关键词：RANSAC;motion panorama;moving object detection3635|205|0更新时间：2024-05-07
- 摘要：Scalable video coding(SVC) technology is a new domain in the processing of image and video,and there are many results of SVC at present.This paper introduces the main concept of SVC and brings forward an effective method to control the velocity of the frame.The result of experiments indicates the Motion Compensated Temporal Filter(MCTF) framework can perform higher velocity of processing and better performance,and also neatly achieve the temporal scalability of SVC.关键词：video compression;scalable video coding;motion compensated temporal filter;wavelet transform2971|168|0更新时间：2024-05-07
- 摘要：Interest in 3D city Modeling and quickly updating have significantly raised in the past years.In this paper,an economically viable solution for city modeling based on strict digital photogrammetric theory is proposed.Two oblique image sequences for buildings' walls and one vertical image sequence for building's roof,acquired by digital video camera on helicopter,coarse 2D vector data of buildings and LIDAR data are used as sources of information.Camera parameters of each image are acquired by automatic aerial triangulation technique for high overlapping image sequence.By matching every space edge of the building to its image line,the building is accurately reconstructed.The visualization of 3D city model is realized based on the reconstructed buildings with fine textures superimposed on DSM and ortho-image.Experimental results in three-dimensional car navigation application show us an attractive future both in efficiency and expression.关键词：3D city modeling;digital photogrammetry;video grammetry;image sequence2389|234|0更新时间：2024-05-07
- 摘要：For a successful augmented reality application,precise projection information of the viewing device is required,which has to calibrate the optical see-through head-mounted display in use.Based on our system,this paper selects the calibration algorithm of the virtual camera which models the combination of HMD and user's eye.According to the influence of degenerate point configurations of projection matrix,the number of calibration correspondences and the track of user's head are improved.Experiments reveal that the calibration effect is meliorated distinctly and the success rate is increased greatly.关键词：augmented reality;optical see-through HMD;display calibration;degenerate point configurations2662|185|0更新时间：2024-05-07
- 摘要：Registration of virtual and real objects is a crucial technology for augmented reality. Because pattern-based algorithm has less operation cost, the method has been used widely in augmented reality. Homography is a mapping relation existing in the pattern-based registration. It has been employed to build the 3D transformation from pattern coordinate to camera coordinate and the 3D-2D transformation from camera coordinate to project coordinate in this paper. As a simple proportional relation, homography cuts back the operation cost. Moreover, it solves the problem of manual calibration. After elaborating the registration course, registration optimization has been further discussed in the paper. The best homography will be selected from several computed results in order to enhance the robustness of registration. The optimization ensures that registration succeeds with partial mark points occluded.关键词：registration;augmented reality;homography;mark point2949|209|0更新时间：2024-05-07
- 摘要：Theoretically, deteriorated images resuhing from imaging system performances can be recovered in a digital way providing that the optical imaging transfer function is known and its inverse function or the approximate inverse function can be found according to the measurement or the priori knowledge of the imaging transfer function. Basically both the imaging transfer functions and the recovery functions are space-variant. Based on space-variant image recovery by inverse filtering with polynomial approximation, we developed a new approach in which the space-variant recovery function is decomposed as the linear combination of a space-invariant base function and its power functions. The base function is such chosen, in recovery, that it brings no error as it corresponds to difference instead of derivative operations. Furthermore, the least square constraint is introduced to the recovery function for regulating the restoration. By this way, a recovered image is the linear combination of the original image and its even-order differences, where the combining coefficients are determined by the system point-spread function, constraint operator, regulation parameter and the decomposition base function. Detailed analysis and derivation of equations are presented and the processed results for both simulated and practical images show the effectiveness of the proposed scheme for deteriorated images with various signal-to-noise ratios.关键词：image restoration;image regulation;space variance;optical imaging systems2506|250|0更新时间：2024-05-07
- 摘要：Relative to the fuzzy membership as a function of distance between the point and its class center in feature space for some current fuzzy support vector machines, a new and more effective fuzzy membership as a function of affinity among samples is proposed for the measurement of the inaccuracy of samples. The fuzzy membership is defined by not only the relation between a sample and its cluster center, but also those among samples, which is described by the fuzzy connectedness among samples. The fuzzy membership based on the affinity among samples for support vector machine effectively distinguishes between support vectors and outliers or noises. Experimental results show that the fuzzy support vector machine, based on the affinity among samples is more robust than the traditional support vector machine, and fuzzy support vector machines taken by other two fuzzy memberships.关键词：support vector machine;fuzzy membership;affinity2816|184|0更新时间：2024-05-07
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