期刊文献+
共找到658篇文章
< 1 2 33 >
每页显示 20 50 100
A Novel Fractal Wavelet Image Compression Approach 被引量:10
1
作者 SONG Chun-lin FENG Rui +1 位作者 LIU Fu-qiang CHEN Xi 《Journal of China University of Mining and Technology》 EI 2007年第1期121-125,共5页
By investigating the limitation of existing wavelet tree based image compression methods, we propose a novel wavelet fractal image compression method in this paper. Briefly, the initial errors are appointed given the ... By investigating the limitation of existing wavelet tree based image compression methods, we propose a novel wavelet fractal image compression method in this paper. Briefly, the initial errors are appointed given the different levels of importance accorded the frequency sublevel band wavelet coefficients. Higher frequency sublevel bands would lead to larger initial errors. As a result, the sizes of sublevel blocks and super blocks would be changed according to the initial errors. The matching sizes between sublevel blocks and super blocks would be changed according to the permitted errors and compression rates. Systematic analyses are performed and the experimental results demonstrate that the proposed method provides a satisfactory performance with a clearly increasing rate of compression and speed of encoding without reducing SNR and the quality of decoded images. Simulation results show that our method is superior to the traditional wavelet tree based methods of fractal image compression. 展开更多
关键词 four-fork tree ADAPTIVE WAVELETS fractal image compression
下载PDF
An improved fast fractal image compression using spatial texture correlation 被引量:2
2
作者 王兴元 王远星 云娇娇 《Chinese Physics B》 SCIE EI CAS CSCD 2011年第10期228-238,共11页
This paper utilizes a spatial texture correlation and the intelligent classification algorithm (ICA) search strategy to speed up the encoding process and improve the bit rate for fractal image compression. Texture f... This paper utilizes a spatial texture correlation and the intelligent classification algorithm (ICA) search strategy to speed up the encoding process and improve the bit rate for fractal image compression. Texture features is one of the most important properties for the representation of an image. Entropy and maximum entry from co-occurrence matrices are used for representing texture features in an image. For a range block, concerned domain blocks of neighbouring range blocks with similar texture features can be searched. In addition, domain blocks with similar texture features are searched in the ICA search process. Experiments show that in comparison with some typical methods, the proposed algorithm significantly speeds up the encoding process and achieves a higher compression ratio, with a slight diminution in the quality of the reconstructed image; in comparison with a spatial correlation scheme, the proposed scheme spends much less encoding time while the compression ratio and the quality of the reconstructed image are almost the same. 展开更多
关键词 fractal image compression texture features intelligent classification algorithm spatialcorrelation
下载PDF
An effective fractal image compression algorithm based on plane fitting 被引量:2
3
作者 王兴元 国兴 张丹丹 《Chinese Physics B》 SCIE EI CAS CSCD 2012年第9期149-155,共7页
A new method using plane fitting to decide whether a domain block is similar enough to a given range block is proposed in this paper. First, three coefficients are computed for describing each range and domain block. ... A new method using plane fitting to decide whether a domain block is similar enough to a given range block is proposed in this paper. First, three coefficients are computed for describing each range and domain block. Then, the best-matched one for every range block is obtained by analysing the relation between their coefficients. Experimental results show that the proposed method can shorten encoding time markedly, while the retrieved image quality is still acceptable. In the decoding step, a kind of simple line fitting on block boundaries is used to reduce blocking effects. At the same time, the proposed method can also achieve a high compression ratio. 展开更多
关键词 fractal image compression plane fitting peak signal to noise ratio gray image
下载PDF
Static Image Compression Based on Fractal Theory 被引量:1
4
作者 Lin Yixia Zhu Quanfan Liu Jun ((School of Automation) 《Advances in Manufacturing》 SCIE CAS 1998年第3期82-85,共4页
In this paper, image compression and decompression are realized on a personal computer based on fractal theory. The algorithm is effectiveas as the reconstructed image is similar to the original. In the algorithm, the... In this paper, image compression and decompression are realized on a personal computer based on fractal theory. The algorithm is effectiveas as the reconstructed image is similar to the original. In the algorithm, the formulas for contrast scaling and luminance shift are simplified,and the Hausdorff distance is replaced by the Euclidean distance. Thus, the calculation load is reduced. The formula for compression ratio is presented for an ideal situation, from which one can analyze how the different factors influence image compression ratio. 展开更多
关键词 fractal iterated function systems image compression
下载PDF
Visual Evaluation of the Morphologic Structure of Nonwovens Using Image Analysis and Fractal Geometry 被引量:1
5
作者 杨旭红 李栋高 《Journal of Donghua University(English Edition)》 EI CAS 2004年第3期162-165,共4页
Nonwovens are fiber materials which are based on nonwoven technologies. For the complexity and randomness of nonwovens morphologic structures, it is difficult to express them effectively using classical method. Fracta... Nonwovens are fiber materials which are based on nonwoven technologies. For the complexity and randomness of nonwovens morphologic structures, it is difficult to express them effectively using classical method. Fractal geometry gives us a new idea and a powerful tool to study on irregularity of geometric objects. Therefore, we studied on the pore size, pore shape, pore size distribution and fiber orientation distribution of real nonwovens using fractal geometry combined with computer image analysis to evaluate nonwovens’ morphologic structures. 展开更多
关键词 NONWOVENS morphologic structure fractal geometry image analysis
下载PDF
Application study of image segmentation methods on pattern recognition in the course of wood across-compression 被引量:1
6
作者 曹军 孙丽萍 +1 位作者 张冬妍 姜宇 《Journal of Forestry Research》 CAS CSCD 2000年第1期57-59,共3页
Image segmentation is one of important steps on pattern recognition study in the course of wood across-compression. By comparing and studying processing methods in finding cell space and cell wall, this paper puts for... Image segmentation is one of important steps on pattern recognition study in the course of wood across-compression. By comparing and studying processing methods in finding cell space and cell wall, this paper puts forward some image segmentation methods that are suitable for study of cell images of wood crossgrained compression. The method of spline function fitting was used for linking edges of cell, which perfects the study of pattern recognition in the course of wood across-compression. 展开更多
关键词 image segmentation Pattern recognition wood across-compression Spline function
下载PDF
Structured-light Image Compression Based on Fractal Theory
7
作者 yan Bao-li Yang Yu-xiao 《Semiconductor Photonics and Technology》 CAS 2002年第1期41-45,共5页
The method of fractal image compression is introduced which is applied to compress the line structured light image. Based on the self similarity of the structured light image, we attain satisfactory compression ratio ... The method of fractal image compression is introduced which is applied to compress the line structured light image. Based on the self similarity of the structured light image, we attain satisfactory compression ratio and higher peak signal to noise ratio (PSNR). The experimental results indicate that this method can achieve high performance. 展开更多
关键词 Structured light profilometry fractal image compression Adaptive quadritree partitioning
下载PDF
Fractal Image Compression Using Self-Organizing Mapping 被引量:1
8
作者 Rashad A. Al-Jawfi Baligh M. Al-Helali Adil M. Ahmed 《Applied Mathematics》 2014年第12期1810-1819,共10页
One of the main disadvantages of fractal image data compression is a loss time in the process of image compression (encoding) and conversion into a system of iterated functions (IFS). In this paper, the idea of the in... One of the main disadvantages of fractal image data compression is a loss time in the process of image compression (encoding) and conversion into a system of iterated functions (IFS). In this paper, the idea of the inverse problem of fixed point is introduced. This inverse problem is based on collage theorem which is the cornerstone of the mathematical idea of fractal image compression. Then this idea is applied by iterated function system, iterative system functions and grayscale iterated function system down to general transformation. Mathematical formulation form is also provided on the digital image space, which deals with the computer. Next, this process has been revised to reduce the time required for image compression by excluding some parts of the image that have a specific milestone. The neural network algorithms have been applied on the process of compression (encryption). The experimental results are presented and the performance of the proposed algorithm is discussed. Finally, the comparison between filtered ranges method and self-organizing method is introduced. 展开更多
关键词 fractal image compression ORGANIZING MAPPING
下载PDF
A Distributed Web GIS Application Based on Component Technology and Fractal Image Compression
9
作者 HAN Jie State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering,HoHai University,Nanjing 210098,China, 《武汉理工大学学报》 CAS CSCD 北大核心 2006年第S3期924-928,共5页
Geographic information system(GIS)technology is a combination of computer’s graphic and database to store and process spatial information.According to the users’ demands,GIS exports the exact geographic information ... Geographic information system(GIS)technology is a combination of computer’s graphic and database to store and process spatial information.According to the users’ demands,GIS exports the exact geographic information and related in- formation for users with map and description through associating geographic place and related attributes.Based on the existing pop- ular technology,this paper presents a distributed web GIS application based on component technology and fractal image compres- sion.It presents the basic framework of the proposed system at first,and then discusses the key technology of implementing this sys- tem;finally it designs a three-layer WEB GIS instance using VC++ATL based on Geo Beans.The example suggests the proposed design is correct,feasible and valid. 展开更多
关键词 GEOGRAPHIC information system web TECHNOLOGY COMPONENT TECHNOLOGY fractal image compression
下载PDF
MULTISCALE IMAGE SEGMENTATION USING FRACTAL AND NEURAL NETWORK
10
作者 Yang Shaoguo Yin Zhongke Luo Bingwei (University of Electronic Science and Technology of China, Chengdu 610054) 《Journal of Electronics(China)》 1999年第4期299-304,共6页
Clustering algorithms in feature space are important methods in image segmentation. The choice of the effective feature parameters and the construction of the clustering method are key problems encountered with cluste... Clustering algorithms in feature space are important methods in image segmentation. The choice of the effective feature parameters and the construction of the clustering method are key problems encountered with clustering algorithms. In this paper, the multifractal dimensions are chosen as the segmentation feature parameters which are extracted from original image and wavelet-transformed image. SOM (Self-Organizing Map) network is applied to cluster the segmentation feature parameters. The experiment shows that the performance of the presented algorithm is very good. 展开更多
关键词 fractal WAVELET TRANSFORM NEURAL network image segmentation
下载PDF
Study of Symmetry Process Behavior in Fractal Gray Image Compression by Traditional Method
11
作者 Eman A. Al-Hilo Kawther H. Al-Khafaji 《Journal of Signal and Information Processing》 2013年第3期176-181,共6页
This paperstudiesthe effect of symmetry process on the compression parameters of thefractal image compression technique proposed by Jacquin.Two kinds of tests have been conducted. The first all kind of the symmetry op... This paperstudiesthe effect of symmetry process on the compression parameters of thefractal image compression technique proposed by Jacquin.Two kinds of tests have been conducted. The first all kind of the symmetry operations [0-7] were taken;while the second tests were concentrated on studying the effect of the following parameters Block Size, Step Size, Domain Size on the probability distribution of symmetry operation. The results show that the higher value of PSNR and the lower value of ET occur atevensymmetry operation only, but compression ratio is not affected with symmetry process. Also the occurrence probability of even symmetry is more than odd symmetry for all compression parameters. This behaviour can be utilized to reducethe encoding time to 50% with preserving PSNR. 展开更多
关键词 image compression Zero-Mean fractal image compression SYMMETRY PROCESS
下载PDF
Fast fractal image compression by pixel peaks and valleys classification
12
作者 HAN Jin-shu 《通讯和计算机(中英文版)》 2007年第3期69-75,共7页
关键词 分形 图像压缩 像素 峰谷 分类 图像处理
下载PDF
A mathematical morphological approach for region of interest coding of microscopy image compression
13
作者 夏伟强 樊尚春 +3 位作者 邢维巍 刘长庭 李天志 王俊峰 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2012年第3期115-121,共7页
A novel mathematical morphological approach for region of interest(ROI) automatic determination and JPEG2000-based coding of microscopy image compression is presented.The algorithm is very fast and requires lower comp... A novel mathematical morphological approach for region of interest(ROI) automatic determination and JPEG2000-based coding of microscopy image compression is presented.The algorithm is very fast and requires lower computing power,which is particularly suitable for some irregular region-based cell microscopy images with poor qualities.Firstly,an active threshold-based method is discussed to create a rough mask of regions of interest(cells).And then some morphological operations are designed and applied to achieve the segmentation of cells.In addition,an extra morphological operation,dilation,is applied to create the final mask with some redundancies to avoid the"edge effect"after removing false cells.Finally,ROI and region of background(ROB) are obtained and encoded individually in different compression ratio flexibly based on the JPEG2000,which can adjust the quality between ROI and ROB without coding for ROI shape.The experimental results certify the effectiveness of the proposed algorithm,and compared with JPEG2000,the proposed algorithm has better performance in both subjective quality and objective quality at the same compression ratios. 展开更多
关键词 mathematical morphology region of interest(ROI) automatic segmentation microscopy image compression JPEG2000
下载PDF
Semantic segmentation-based semantic communication system for image transmission
14
作者 Jiale Wu Celimuge Wu +4 位作者 Yangfei Lin Tsutomu Yoshinaga Lei Zhong Xianfu Chen Yusheng Ji 《Digital Communications and Networks》 SCIE CSCD 2024年第3期519-527,共9页
With the rapid development of artificial intelligence and the widespread use of the Internet of Things, semantic communication, as an emerging communication paradigm, has been attracting great interest. Taking image t... With the rapid development of artificial intelligence and the widespread use of the Internet of Things, semantic communication, as an emerging communication paradigm, has been attracting great interest. Taking image transmission as an example, from the semantic communication's view, not all pixels in the images are equally important for certain receivers. The existing semantic communication systems directly perform semantic encoding and decoding on the whole image, in which the region of interest cannot be identified. In this paper, we propose a novel semantic communication system for image transmission that can distinguish between Regions Of Interest (ROI) and Regions Of Non-Interest (RONI) based on semantic segmentation, where a semantic segmentation algorithm is used to classify each pixel of the image and distinguish ROI and RONI. The system also enables high-quality transmission of ROI with lower communication overheads by transmissions through different semantic communication networks with different bandwidth requirements. An improved metric θPSNR is proposed to evaluate the transmission accuracy of the novel semantic transmission network. Experimental results show that our proposed system achieves a significant performance improvement compared with existing approaches, namely, existing semantic communication approaches and the conventional approach without semantics. 展开更多
关键词 Semantic Communication Semantic segmentation image transmission image compression Deep learning
下载PDF
A semantic segmentation-based underwater acoustic image transmission framework for cooperative SLAM
15
作者 Jiaxu Li Guangyao Han +1 位作者 Shuai Chang Xiaomei Fu 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第3期339-351,共13页
With the development of underwater sonar detection technology,simultaneous localization and mapping(SLAM)approach has attracted much attention in underwater navigation field in recent years.But the weak detection abil... With the development of underwater sonar detection technology,simultaneous localization and mapping(SLAM)approach has attracted much attention in underwater navigation field in recent years.But the weak detection ability of a single vehicle limits the SLAM performance in wide areas.Thereby,cooperative SLAM using multiple vehicles has become an important research direction.The key factor of cooperative SLAM is timely and efficient sonar image transmission among underwater vehicles.However,the limited bandwidth of underwater acoustic channels contradicts a large amount of sonar image data.It is essential to compress the images before transmission.Recently,deep neural networks have great value in image compression by virtue of the powerful learning ability of neural networks,but the existing sonar image compression methods based on neural network usually focus on the pixel-level information without the semantic-level information.In this paper,we propose a novel underwater acoustic transmission scheme called UAT-SSIC that includes semantic segmentation-based sonar image compression(SSIC)framework and the joint source-channel codec,to improve the accuracy of the semantic information of the reconstructed sonar image at the receiver.The SSIC framework consists of Auto-Encoder structure-based sonar image compression network,which is measured by a semantic segmentation network's residual.Considering that sonar images have the characteristics of blurred target edges,the semantic segmentation network used a special dilated convolution neural network(DiCNN)to enhance segmentation accuracy by expanding the range of receptive fields.The joint source-channel codec with unequal error protection is proposed that adjusts the power level of the transmitted data,which deal with sonar image transmission error caused by the serious underwater acoustic channel.Experiment results demonstrate that our method preserves more semantic information,with advantages over existing methods at the same compression ratio.It also improves the error tolerance and packet loss resistance of transmission. 展开更多
关键词 Semantic segmentation Sonar image transmission Learning-based compression
下载PDF
A Compression Algorithm of Hyperspectral Remote Sensing Image Based on 3-D Wavelet-Fractal Coder
16
作者 邹毅 潘伟 敖露 《Journal of Donghua University(English Edition)》 EI CAS 2010年第2期229-232,共4页
In this paper, the 3-D Wavelet-Fractal coder was used to compress the hyperspectral remote sensing image, which is a combination of 3-D improved set partitioning in hierarchical trees (SPIHT) coding and 3-D fractal ... In this paper, the 3-D Wavelet-Fractal coder was used to compress the hyperspectral remote sensing image, which is a combination of 3-D improved set partitioning in hierarchical trees (SPIHT) coding and 3-D fractal coding. Hyperspectral image date cube was first translated by 3-D wavelet and the 3-D fractal compression ceding was applied to lowest frequency subband. The remaining coefficients of higher frequency sub-bands were encoding by 3-D improved SPIHT. We used the block set instead of the hierarchical trees to enhance SPIHT's flexibility. The classical eight kinds of affme transformations in 2-D fractal image compression were generalized to nineteen for the 3-D fractal image compression. The new compression method had been tested on MATLAB. The experiment results indicate that we can gain high compression ratios and the information loss is acceptable. 展开更多
关键词 image compression three dimensional improved SPIHT fractal compression coding HYPERSPECTRAL
下载PDF
A hyperspectral image compression algorithm based on wavelet transformation and fractal composition (AWFC) 被引量:1
17
作者 HU Xingtang ZHANG Bing ZHANG Xia ZHENG Lanfen TONG Qingxi 《Science China(Technological Sciences)》 SCIE EI CAS 2006年第z2期48-56,共9页
Starting with a fractal-based image-compression algorithm based on wavelet transformation for hyperspectral images, the authors were able to obtain more spectral bands with the help of of hyperspectral remote sensing.... Starting with a fractal-based image-compression algorithm based on wavelet transformation for hyperspectral images, the authors were able to obtain more spectral bands with the help of of hyperspectral remote sensing. Because large amounts of data and limited bandwidth complicate the storage and transmission of data measured by TB-level bits, it is important to compress image data acquired by hyperspectral sensors such as MODIS, PHI, and OMIS; otherwise, conventional lossless compression algorithms cannot reach adequate compression ratios. Other loss-compression methods can reach high compression ratios but lack good image fidelity, especially for hyperspectral image data. Among the third generation of image compression algorithms, fractal image compression based on wavelet transformation is superior to traditional compression methods,because it has high compression ratios and good image fidelity, and requires less computing time. To keep the spectral dimension invariable, the authors compared the results of two compression algorithms based on the storage-file structures of BSQ and of BIP, and improved the HV and Quadtree partitioning and domain-range matching algorithms in order to accelerate their encode/decode efficiency. The authors' Hyperspectral Image Process and Analysis System (HIPAS) software used a VC++6.0 integrated development environment (IDE), with which good experimental results were obtained. Possible modifications of the algorithm and limitations of the method are also discussed. 展开更多
关键词 WAVELET transformation fractal coding image compression HYPERSPECTRAL image HIPAS.
原文传递
Chaos-based encryption for fractal image coding 被引量:3
18
作者 袁正雄 黄国和 《Chinese Physics B》 SCIE EI CAS CSCD 2012年第1期115-126,共12页
A chaos-based cryptosystem for fractal image coding is proposed. The Renyi chaotic map is employed to determine the order of processing the range blocks and to generate the keystream for masking the encoded sequence. ... A chaos-based cryptosystem for fractal image coding is proposed. The Renyi chaotic map is employed to determine the order of processing the range blocks and to generate the keystream for masking the encoded sequence. Compared with the standard approach of fraetal image coding followed by the Advanced Encryption Standard, our scheme offers a higher sensitivity to both plaintext and ciphertext at a comparable operating efficiency. The keystream generated by the Renyi chaotic map passes the randomness tests set by the United States National Institute of Standards and Technology, and so the proposed scheme is sensitive to the key. 展开更多
关键词 CHAOS CRYPTOGRAPHY joint image compression and encryption fractal image coding
下载PDF
An Adaptive Block-Based Fractal Image Coding Scheme
19
作者 邓元木 柯有安 《Journal of Beijing Institute of Technology》 EI CAS 1996年第2期183+177-183,共8页
Based on Jacquin's work. this paper presents an adaptive block-based fractal image coding scheme. Firstly. masking functions are used to classify range blocks and weight the mean Square error (MSE) of images. Seco... Based on Jacquin's work. this paper presents an adaptive block-based fractal image coding scheme. Firstly. masking functions are used to classify range blocks and weight the mean Square error (MSE) of images. Secondly, an adaptive block partition scheme is introduced by developing the quadtree partition method. Thirdly. a piecewise uniform quantization strategy is appled to quantize the luminance shifting. Finally. experiment results are shown and compared with what reported by Jacquin and Lu to verify the validity of the methods addressed by the authors. 展开更多
关键词 fractal technique image compression image coding
下载PDF
Fractal image encoding based on adaptive search 被引量:1
20
作者 Kya Berthe 《Journal of University of Science and Technology Beijing》 CSCD 2003年第6期67-71,共5页
Finding the optimal algorithm between an efficient encoding process and therate distortion is the main research in fractal image compression theory. A new method has beenproposed based on the optimization of the Least... Finding the optimal algorithm between an efficient encoding process and therate distortion is the main research in fractal image compression theory. A new method has beenproposed based on the optimization of the Least-Square Error and the orthogonal projection. A largenumber of domain blocks can be eliminated in order to speed-up fractal image compression. Moreover,since the rate-distortion performance of most fractal image coders is not satisfactory, an efficientbit allocation algorithm to improve the rate distortion is also proposed. The implementation andcomparison have been done with the feature extraction method to prove the efficiency of the proposedmethod. 展开更多
关键词 fractal optimization bit allocation adaptive search image compression
下载PDF
上一页 1 2 33 下一页 到第
使用帮助 返回顶部