共查询到20条相似文献，搜索用时 828 毫秒
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林寿光 《宁波职业技术学院学报》2010,14(5):66-68
利用哈夫曼压缩编码的原理及方法,采用MATLAB软件对两幅图片进行压缩编码程序设计,获得压缩信息及哈夫曼编码表,分析压缩后的图像像素数据及压缩比。结果表明,哈夫曼编码是一种无损压缩编码。 相似文献
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为解决手工提取图像特征过程繁复和参数复杂问题,提出一种基于深度学习的协同KPCANet模型。该算法能够对现场采集到的人脸数据和特征进行提取和分类,通过提取分块直方图特征进行编码协同表示,将测试样本归于残差最小的类中对人脸数据进行识别和运算。实验结果表明,协同KPCANet模型在滤波器数量L1=10时一层卷积层与L2=15时二层卷积层的正确率分别达到99.17%和99.44%。协同KPCANet模型不仅能使运算过程简洁,还能提高识别结果准确度,提升识别效率。 相似文献
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利用边缘像素负载信息的二值图像密写 总被引：4，自引：0，他引：4
We present a novel scheme for embedding secret data into a binary image without introducing noticeable artifacts. Unlike some block-based methods, the proposed scheme encodes the secret bits directly into boundary pixels by checking each pixel of the cover image in a pseudo-random order for embedding eligibility. A set of rules ensures correct identification of data-carrying pixels in blind extraction. The proposed scheme does not generate isolated dots, and can incorporate various coding methods such as matrix encoding to further improve the embedding performance. It is shown that up to one fourth of the boundary pixels may be used to carry secret data. Experimental results indicate that the method can achieve good visual quality with fairly large data capacity. 相似文献
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It is known by entropy theory that image is a source correlated with a certain characteristic of probability. The entropy rate of the source and ? entropy (rate-distortion function theory) are the information content to identify the characteristics of video images, and hence are essentially related with video image compression. They are fundamental theories of great significance to image compression, though impossible to be directly turned into a compression method. Based on the entropy theory and the image compression theory, by the application of the rate-distortion feature mathematical model and Lagrange multipliers to some theoretical problems in the H.264 standard, this paper presents a new the algorithm model of coding rate-distortion. This model is introduced into complete test on the capability of the test model of JM61e (JUT Test Model). The result shows that the speed of coding increases without significant reduction of the rate-distortion performance of the coder. 相似文献
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一种基于零树的树形扫描图像压缩编码方法 总被引：1，自引：0，他引：1
金彩虹 《宁夏师范学院学报》2004,25(6):7-10
嵌入式零树编码被认为是目前国际上最先进的图像编码方法之一，但该算法在编“孤立零”码时会造成比特位冗余．因此本文提出了基于零树的树形扫描的图像压缩编码方法．实验结果表明该方法在保证恢复图像具有良好视觉效果的前提下，提高了压缩比，缩短了编码时间． 相似文献
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Image subbands can be obtained by using filterbank. Traditional compression method uses direct entropy coding for each subband. After studying the energy distribution in image subbands, we proposed a vector quantization (VQ) coding algorithm to image subband. In the algorithm, vector quantizers were adaptively designed for high-frequency bands in an image. In particular, the edges of the image were examined and fewer bits were assigned to high-energy regions. The experimental result showe… 相似文献
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介绍了预测编码、变换编码、分形图像编码等几种常用的图像压缩编码方法,在进行系统分析和比较的基础上,指出了各种压缩编码方法的优缺点,阐明了压缩技术未来的技术发展方向和应用发展方向. 相似文献
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分形图像压缩编码是图像压缩领域中一种全新的编码算法,具有潜在的高压缩比、高信噪比以及任意尺度上的精细放大等特性。本文论述了分形图像压缩的背景、编码方法、改进方法和发展趋势。 相似文献
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lintroductionCompressionofdigitalimagesandvideosignalstoreducetheirstorageandtransmissionbandwidthrequirementsisofgreatinterestintheimplementationofcolnnlunicationsystems.Moreandmorecompressioncodingmethod$fordigitalimagesandvideosignalshavebeenproposedto… 相似文献
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合成孔径雷达(SAR:Synthetic Aperture Radar)具有海量的成像数据,极大的动态范围,不仅要用浮点来表示数据,而且令JPEGJ、PEG 2000和H.264等标准最初为光学图像而设计,并且主要针对8比特整数图像数据的标准压缩算法难以胜任.本文应某研究所的要求,针对32位的SAR浮点模图像数据, 相似文献
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分形图像压缩编码技术以新颖的思想冲破了传统图像编码方法的理论框架,为图像编码开辟了一条新的途径,成为当今图像压缩领域中最新的方法之一。文章对分形图像压缩编码发展的历史与现状进行了研究,分析了分形图像压缩编码的特点与存在的不足,以及针对不足所采取的一些改进方法。 相似文献
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HU Yuping YU Shengsheng ZHOU JingLi SHI Lei College of Computer Science Technology Huazhong University of Science Technology Wuhan P.R. China 《重庆大学学报(英文版)》2004,3(1):34-38
1.IntroductionInrecentyears,digitalimagewatermarkingtechni-queshavegrowndramatically.Digitalimagewater-markingisconcernedwithhidinginformationintoadigitalimage.Thisinformationmaybeusedforvariousapplicationssuchasauthentication,copyright,andproofofownership.Insomeapplicationsitisrequirednotonlytoidentifytherightfuluserofanimage,butalsotoembedsomeadditionalinformation.Forexample,incopyrightprotectionapplication,thewatermarkmaycontainadate,atime,aserialnumber,oranidentificationoftherightfuluser.… 相似文献
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1 Ｉｎｔｒｏｄｕｃｔｉｏｎ Ｔｈｅｉｍａｇｅｌｏｓｓｌｅｓｓｃｏｍｐｒｅｓｓｉｏｎｃｏｄｉｎｇｉｓａｎｉｍｐｏｒｔａｎｔｐａｒｔｏｆｔｈｅｄｉｇｉｔａｌｉｍａｇｅｃｏｍｐｒｅｓｓｉｏｎｒｅｓｅａｒｃｈ .Ｍｅｄｉｃａｌｉｍａｇｅｓ,ｓａｔｅｌｌｉｔｅｉｍａｇｅｓａｎｄｓｅｉｓｍｉｃｄａｔａｄｅｍａｎｄｌｏｓｓ ｌｅｓｓｃｏｄｉｎｇ .Ｔｈｅｂａｓｉｃｉｄｅａｏｆｃｏｍｐｒｅｓｓｉｏｎｉｓｔｏｅｘｐｌｏｉｔｔｈｅｃｏｒｒｅｌａｔｉｏｎｓｔｒｕｃｔｕｒｅｐｒｅｓｅｎｔｅｄｉｎｍｏｓｔｒｅａｌｌｉｆｅｉｍ … 相似文献
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孙洪 《新疆教育学院学报》2004,20(2):96-98
本文介绍了图像压缩的原因及数字图像压缩缟码。对图像压缩缟码技术中有关无损压缩的几种方法进行了比较，对其中适合于实际应用的无损压缩算法进行了探讨。 相似文献
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An addition scheme applicable to time-delay integration (TDI) CMOS image sensor is proposed,which adds signals in the charge domain in the pixel array.A two-shared pixel structure adopting two-stage charge transfer is introduced,together with the rolling shutter with an undersampling readout timing.Compared with the conventional TDI addition methods,the proposed scheme can reduce the addition operations by half in the pixel array,which decreases the power consumption of addition circuits outside the pixel array.The timing arrangement and pixel structure are analyzed in detail.The simulation results show that the proposed pixel structure can achieve the charge addition with negligible nonlinearity,therefore the power consumption of the periphery addition circuits can be reduced by half theoretically. 相似文献
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《天津大学学报(英文版)》2017,(6)
Conventional camera calibration that employs calibration targets is a commonly used method to acquire a camera's intrinsic and/or extrinsic parameters. The calibration targets are usually designed as periodic arrays of simple high-contrast patterns that provide highly accurate world coordinate system points and the corresponding image pixel coordinate system points. The existing pixel coordinate extraction algorithms can reach a sub-pixel level; however, they treat each single pattern in one image as an independent individual, which makes it difficult to further improve extraction accuracy. In this paper, a novel method is proposed by utilizing the periodic arrangement characteristics of the calibration target pattern as a global constraint to improve the calibration accuracy. Based on a camera's pinhole model, the intersection point of two fitted curves is used as an optimized pixel point to replace the initial one. Following the pixel coordinate optimization procedures, experiments were performed using real data from a 3D laser line scanner and a dynamic precision calibration target. Our results show that the relative errors of camera homography matrix elements obtained by the proposed optimization method were reduced compared with the commonly used method. The average coordinate measurement accuracy can be improved by nearly 0.05 mm. It is shown that the proposed optimization method can enhance the camera calibration accuracy,especially when the extracted pixels are of poorer precision. 相似文献
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李靖 《天津职业院校联合学报》2012,14(8):51-53
为了满足某些图像的高效存储及快速传送的目的,提出一种基于感兴趣区域（ROI）的压缩算法。对图像进行分析,选出ROI区域,并在小波变换的基础上,对ROI小波变换低频子带采用无损编码的方法,而对ROI高频子带及非ROI小波变换子带采用改进的SPIHT压缩编码算法。在保证了图像所含信息量的同时,增加了图像的压缩编码效率。 相似文献