首页 | 本学科首页   官方微博 | 高级检索  
检索     
共有20条相似文献,以下是第1-20项 搜索用时 109 毫秒

1.  On the orders of transformation matrices (mod n) and two types of generalized Arnold transformation matrices  被引次数:1
   YANG Lizhen & CHEN Kefei Department of Computer Science and Engineering  Shanghai Jiaotong University  Shanghai 200030  China《中国科学F辑(英文版)》,2004年第47卷第5期
   With the rapid development of information technology, more and more private and public information is distributed through the Internet. The problem of how to distribute information securely through the Internet has arisen. Recently, a lot of technologies have been developed to ensure the security of information. Information hiding[1] is one of these, ranging from digital watermarking, digital fingerprint to steganography. The scrambling transformation is one of the technologies of image infor…    

2.  COMPARISON AND ANALYSIS OF THREE DIFFERENT NON-CONTACTING FLAME TEMPERATURE FIELD MEASUREMENTS  被引次数:1
   Feng ZhiminWang YingHu HaigangLang HaoxiangDepartment of Marine Engineering  Ningbo University  Ningbo 315211  China《机械工程学报(英文版)》,2003年第16卷第2期
   A much better substitutional means is discussed to calculate the flame temperature field with the application of digital image processing technology. Three non-contacting temperature measurements are used and compared. Such as the traditional two-color temperature measurement,the CCD filtering two-color temperature measurement and the monochromatic temperature measurement. It is indicated that the CCD two-color temperature measurement is not a fully correct means because of its poor theoretical basis. The monochromatic temperature measurement acquires a relatively ideal temperature field distribution in spite of needing a reference temperature. It should be noted that the Abel transformation applied in the plasma diagnosis is for the first time introduced to solve the problem of three-dimensional flame brightness piling.    

3.  Non-rigid registration of mural images and laser scanning data based on the optimization of the edges of interest  
   ZHANG Fan  HUANG XianFeng  FANG Wei  LI DeRen《中国科学:信息科学(英文版)》,2013年第6期
   The orientation and correction of mural images by registering them with laser scanning data is critical for the digital protection of ancient murals.This paper proposes a method for the non-rigid registration of mural images and laser scanning data based on the optimization of the edge of interest by using laser echo intensity information as an intermediary.First,the intensity image was generated from the laser echo intensity information,and registered with the mural image using a rigid transformation model.Second,the edges of interest in the mural image and the gradient field of the intensity images were processed as registration primitives.Third,every edge of interest was registered with the optimization base used in the rigid registration of the mural image and intensity image.Finally,the registration was completed after a non-rigid transformation model between these two images was constructed using the control points on the optimized edges.Our experimental results show that the proposed method can obtain high registration accuracy for different data sets.    

4.  A Medical Image Segmentation Method Based on SOM and Wavelet Transforms  
   Jianxun Zhang Quanli Liu Zhuang Chen《通讯和计算机》,2005年第2卷第5期
   Image segmentation plays a crucial role in many medical imaging applications and is an important but inherently difficult problem. This paper discusses the method that classifies unsupervised image using a Kohonen self-organizing map neural network. This method has two problems: training time of the network is too long and the classified result and quantity are much easily influenced by the noise of image. Two-dimensional Discrete Wavelet Transforms (DWT) decompose MRI image into the small size and denoise approximation images. Kohonen self-organizing map neural network is trained with approximation image, then trained neural network classify pixels of original image. Training time of the network is markedly decreased and the classified quality influenced by the noise of image is markedly reduced. The technique presented here has shown a very encouraging level of performance for the problem of segmentation in MRI image of the head.    

5.  A Scheme for Reconstructing Free-form Surface from Shading with Cellular Automata  
   XU Bin TANG Linxin SHI Hanmin 《武汉理工大学学报》,2006年第28卷第Z2期
   The reconstruction of free-form surface is a fundamental problem in digital manufacture.This article presents a novel solution to reconstructing free-form surface from an intensity image under the Lambertian reflection model,that is a method called shape from shading (SFS).Our approach is based on the two-dimensional cellular automata (CA),and fully uses the local information of both image and the reconstructed surface.After several iterations,the free-form surface corresponding to the input image is obtained.The encouraging results on both synthetic and real-world images are provided in this paper,and the perfor- mance of our algorithm is analyzed on synthetic images using mean and standard deviation of depth (Z) errors.    

6.  Two Dimensional Spatial Independent Component Analysis and Its Application in fMRI Data Process  
   CHEN Hua-fu YAO De-zhong《中国电子科技》,2005年第3卷第3期
   One important application of independent component analysis (ICA) is in image processing. A two dimensional (2-D) composite ICA algorithm framework for 2-D image independent component analysis (2-D ICA) is proposed. The 2-D nature of the algorithm provides it an advantage of circumventing the roundabout transforming procedures between two dimensional (2-D) image deta and one-dimensional (l-D) signal. Moreover the combination of the Newton (fixed-point algorithm) and natural gradient algorithms in this composite algorithm increases its efficiency and robustness. The convincing results of a successful example in functional magnetic resonance imaging (fMRI) show the potential application of composite 2-D ICA in the brain activity detection.    

7.  The Study of Otsu Algorithm Applied in the Measuring of Ash Proportion  
   Weihua Pan  Jinghai Wang《计算机技术与应用:英文》,2013年第8期
   To further improve the boiler ash ratio detection methods and resource utilization, through image processing technology for boiler ash ratio analysis, the article first studied the one-dimensional Otsu algorithm, and then for the one-dimensional Otsu algorithm, in order to improve the accuracy of the algorithm, then it puts forward a two-dimensional Otsu algorithm. Finally the two-dimensional Otsu algorithm combined with the one-dimensional Otsu algorithm and the improved Otsu algorithm. By analyzing the improved Otsu algorithm, this paper considers the pixel gray value, neighborhood information, excluding light, noise and the relative efficiency of one-dimensional Otsu algorithm higher accuracy. The relative dimensional Otsu algorithm operating efficiency has been greatly improved. Improved Otsu algorithm in dealing with boiler ash ratio detection has played a very good part in the ecological environment, economic development and some other important aspects.    

8.  Digital Image Watermarking Based on Discrete Wavelet Transform  被引次数:7
   丁玮  闫伟齐  齐东旭《计算机科学技术学报》,2002年第17卷第2期
   This paper aims at digital watermark which is a new popular research topic recently,presents some methods to embed digital watermark based on modifying frequency coefficients in discrete wavelet transform(DWT) domian,Fist,the,the present progress of digital watermark is briefly introduced;after that,starting from Pitas‘s method and discarding his pseudo random number method,the authors use a digital image scrambling technology as preprocessing for digital watermarking ,Then the authors discuss how to embed a 1-bit digital image as watermark in frequency domain.Finally another digital watermarking method is given in which3-D DWT is used to transform a given digtial image .Based on the experimental results ,it is shown that the proposed methods are robust to a large extent.    

9.  Image auto-zoom technology for AFM automation  
   刘文良  钱建强  李渊《光电子快报》,2009年第5卷第2期
   For the case of atomic force microscope (AFM) automation, we extract the most valuable sub-region of a given AFM image automatically for succeeding scanning to get the higher resolution of interesting region. Two objective functions are sum- marized based on the analysis of evaluation of the information of a sub-region, and corresponding algorithm principles based on standard deviation and Discrete Cosine Transform (DCT) compression are determined from math. Algorithm realizations are analyzed and two selec...    

10.  Content-based image retrieval using high-dimensional information geometry  
   CAO WenMing  LIU Ning  KONG QiCong  FENG Hao《中国科学:信息科学(英文版)》,2014年第7期
   In this paper,a new content-based image retrieval approach is proposed based on high-dimensional information theory.The proposed approach overcomes the disadvantages of the current content-based image retrieval algorithms that suffer from the semantic gap.First,we present a new multidimensional information space’s vector angle cosine algorithm of high-dimensional geometry,then,we provide a detailed description of our images retrieval method including proposal of an overlapping image block method and definition of a similarity degree between images on the non-dimensional information subspaces.Finally,experimental results show the higher retrieval efficiency of the proposed algorithm.    

11.  A NOVEL ALGORITHM OF MULTI-SENSOR IMAGE FUSION BASED ON WAVELET PACKET TRANSFORM  被引次数:1
   Cheng Yinglei Zhao Rongchun Hu Fuyuan Li Ying《电子科学学刊(英文版)》,2006年第23卷第2期
   In order to enhance the image information from multi-sensor and to improve the abilities of the information analysis and the feature extraction, this letter proposed a new fusion approach in pixel level by means of the Wavelet Packet Transform (WPT). The WPT is able to decompose an image into low frequency band and high frequency band in higher scale. It offers a more precise method for image analysis than Wavelet Transform (WT). Firstly, the proposed approach employs HIS (Hue, Intensity, Saturation) transform to obtain the intensity component of CBERS (China-Brazil Earth Resource Satellite) multi-spectral image. Then WPT transform is employed to decompose the intensity component and SPOT (Systeme Pour I'Observation de la Therre ) image into low frequency band and high frequency band in three levels. Next, two high frequency coefficients and low frequency coefficients of the images are combined by linear weighting strategies. Finally, the fused image is obtained with inverse WPT and inverse HIS. The results show the new approach can fuse details of input image successfully, and thereby can obtain a more satisfactory result than that of HM (Histogram Matched)-based fusion algorithm and WT-based fusion approach.    

12.  Probabilistic hypergraph based hash codes for social image search  
   Yi Xie  Hui-min Yu  Roland Hu《浙江大学学报:C卷英文版》,2014年第15卷第7期
   With the rapid development of the Internet, recent years have seen the explosive growth of social media. This brings great challenges in performing efficient and accurate image retrieval on a large scale. Recent work shows that using hashing methods to embed high-dimensional image features and tag information into Hamming space provides a powerful way to index large collections of social images. By learning hash codes through a spectral graph partitioning algorithm, spectral hashing(SH) has shown promising performance among various hashing approaches. However, it is incomplete to model the relations among images only by pairwise simple graphs which ignore the relationship in a higher order. In this paper, we utilize a probabilistic hypergraph model to learn hash codes for social image retrieval. A probabilistic hypergraph model offers a higher order repre-sentation among social images by connecting more than two images in one hyperedge. Unlike a normal hypergraph model, a probabilistic hypergraph model considers not only the grouping information, but also the similarities between vertices in hy-peredges. Experiments on Flickr image datasets verify the performance of our proposed approach.    

13.  Image dehazing based on haziness analysis  
   Fan Guo  Jin Tang  Zi-Xing Cai《国际自动化与计算杂志》,2014年第11卷第1期
   We present two haze removal algorithms for single image based on haziness analysis.One algorithm regards haze as the veil layer,and the other takes haze as the transmission.The former uses the illumination component image obtained by retinex algorithm and the depth information of the original image to remove the veil layer.The latter employs guided filter to obtain the refined haze transmission and separates it from the original image.The main advantages of the proposed methods are that no user interaction is needed and the computing speed is relatively fast.A comparative study and quantitative evaluation with some main existing algorithms demonstrate that similar even better quality results can be obtained by the proposed methods.On the top of haze removal,several applications of the haze transmission including image refocusing,haze simulation,relighting and 2-dimensional(2D)to 3-dimensional(3D) stereoscopic conversion are also implemented.    

14.  Research on Manufacturing Technology Based on Machine Vision  
   HU Zhanqi ZHENG Kuijing 《武汉理工大学学报》,2006年第28卷第Z2期
   The concept of machine vision based manufacturing technology is proposed first,and the key algorithms used in two-dimensional and three-dimensional machining are discussed in detail.Machining information can be derived from the binary images and gray picture after processing and transforming the picture.Contour and the parallel cutting method about two-dimen- sional machining are proposed.Polygon approximating algorithm is used to cutting the profile of the workpiece.Fill Scanning al- gorithm used to machining inner part of a pocket.The improved Shape From Shading method with adaptive pre-processing is adopted to reconstruct the three-dimensional model.Layer cutting method is adopted for three-dimensional machining.The tool path is then gotten from the model,and NC code is formed subsequently.The model can be machined conveniently by the lathe, milling machine or engraver.Some examples are given to demonstrate the results of lmageCAM system,which is developed by the author to implement the algorithms previously mentioned.    

15.  A Novel and Efficient Method for Iris Automatic Location  被引次数:1
   XU Guang-zhu ZHANG Zai-feng MA Yi-de《中国矿业大学学报(英文版)》,2007年第17卷第3期
   An efficient and robust iris location algorithm plays a very important role in a real iris recognition system. A novel and efficient iris automatic location method is presented in this study. It includes following two steps mainly: pu- pil location and iris outer boundary location. A digital eye image was divided into many small rectangular blocks with fixed size in the pupil location, and the block with the smallest average intensity was selected as a reference area. Then image binarization was implemented taking the average intensity of the reference area as a threshold. At last the center coordinates and radius of pupil were estimated by extending the reference area to the pupil's boundaries in the binary iris image. In the iris outer location, two local parts of the eye image were selected and transformed into polar coordinates from Cartesian reference. In order to detect the fainter outer boundary of the iris quickly, a novel edge detector was used to locate boundaries of the two parts. The center coordinates and radius of the iris outer boundary can be estimated using the fusion of the locating results of the two local parts and the location information of the pupil. The algorithm was tested on CASIA vl.0 and MMU vl.0 digital eye image databases and experimental results show that the proposed method has satisfying performance and good robustness.    

16.  Multi-spectral image fusion method based on two channels non-separable wavelets  被引次数:4
   Bin Liu  JiaXiong Peng《中国科学F辑(英文版)》,2008年第51卷第12期
   A construction method of two channels non-separable wavelets filter bank which dilation matrix is [1, 1; 1,-1] and its application in the fusion of multi-spectral image are presented. Many 4×4 filter banks are designed. The multi-spectral image fusion algorithm based on this kind of wavelet is proposed. Using this filter bank, multi-resolution wavelet decomposition of the intensity of multi-spectral image and panchromatic image is performed, and the two low-frequency components of the intensity and the panchromatic image are merged by using a tradeoff parameter. The experiment results show that this method is good in the preservation of spectral quality and high spatial resolution information. Its performance in preserving spectral quality and high spatial information is better than the fusion method based on DWFT and IHS. When the parameter t is closed to 1, the fused image can obtain rich spectral information from the original MS image. The amount of computation reduced to only half of the fusion method based on four channels wavelet transform.    

17.  New Optimal DWT Domain Image Watermarking Technique via Genetic Algorithm  
   钟宁  匡镜明  何遵文《北京理工大学学报(英文版)》,2007年第16卷第4期
   A novel optimal image watermarking scheme is proposed in which the genetic algorithm (GA) is employed to obtain the improvement of algorithm performance. Arnold transform is utilized to obtain the scrambled watermark, and then the embedding and extractio    

18.  Robust Audio Blind Watermarking Algorithm Based on Haar Transform  
   Bao-Yuan Chen  Yi-Qiang Zhu  Lei-Lei Tian  Ying-Ying Li  Ya-Qiong Lan《哈尔滨工业大学学报(英文版)》,2013年第20卷第3期
   To solve the problem of low capacity of audio watermarking information and poor robustness of impact resistance, a digital audio watermark algorithm based on wavelet transform is presented in this paper. In this algorithm, the fine and approximate components are obtained when the Haar wavelet base is used to convert each frame of the audio signal to its discrete transform. Then the HAS algorithm is applied to the fine component embedded with watermark to realize encryption process. The original audio carrier signal is not needed in extraction, as long as the signal is embedded after the frame is divided. The first two sections of each frame are implemented in Haar transform respectively to get the fine and approximate component. The watermark images are obtained from the former two fine components of the energy watermark sequence after calculating, comparing and extracting. The simulation results show that there is a certain transparency for the algorithm, a good robustness against the resampling and low pass filtering attack.    

19.  THE STRIP IMAGING OF AIRBORNE SQUINT SIDELOOKING MODE SAR  
   Dai Shengli 《电子科学学刊(英文版)》,1999年第16卷第1期
   Airborne squint side-looking strip imaging mode SAR has the advantages of better flexibility and larger field in applications than the classic side-looking mode SAR. Because of the large range migration and serious range-azimuth coupling terms, the imaging processing of squint mode SAR is a full two-dimensional (2-D) phenomenon. In this paper, different algorithms, which can be used for the imaging processing of squint mode SAR, are compared with each other in terms of their focusing quality and their ability to handle the large range migration of the squint side-looking mode SAR. And their abilities of real-time imaging are also discussed. The algorithms contained here are 2-D FFT method, fast polynomial transform(FPT) method, and the direct correcting method based on range-Doppler focusing algorithms. Other new methods are also discussed here briefly.    

20.  MULTI-SPECTRAL AND HYPERSPECTRAL IMAGE FUSION USING 3-D WAVELET TRANSFORM  
   Zhang Yifan He Mingyi《电子科学学刊(英文版)》,2007年第24卷第2期
   Image fusion is performed between one band of multi-spectral image and two bands of hyperspectral image to produce fused image with the same spatial resolution as source multi-spectral image and the same spectral resolution as source hyperspeetral image. According to the characteristics and 3-Dimensional (3-D) feature analysis of multi-spectral and hyperspectral image data volume, the new fusion approach using 3-D wavelet based method is proposed. This approach is composed of four major procedures: Spatial and spectral resampling, 3-D wavelet transform, wavelet coefficient integration and 3-D inverse wavelet transform. Especially, a novel method, Ratio Image Based Spectral Resampling (RIBSR)method, is proposed to accomplish data resampling in spectral domain by utilizing the property of ratio image. And a new fusion rule, Average and Substitution (A&S) rule, is employed as the fusion rule to accomplish wavelet coefficient integration. Experimental results illustrate that the fusion approach using 3-D wavelet transform can utilize both spatial and spectral characteristics of source images more adequately and produce fused image with higher quality and fewer artifacts than fusion approach using 2-D wavelet transform. It is also revealed that RIBSR method is capable of interpolating the missing data more effectively and correctly, and A&S rule can integrate coefficients of source images in 3-D wavelet domain to preserve both spatial and spectral features of source images more properly.    

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号