共查询到19条相似文献,搜索用时 171 毫秒
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传真图像的信息量非常大,对其进行数据压缩,不仅可以节省存储空间,而且可以有效地降低传输时间。针对MR码,设计了一种编码和译码算法,并利用MATLAB软件进行实现;采用该算法对传真图像进行数据压缩,并比较MH编码和MR编码的压缩比,仿真实验表明,该算法可以满足传真图像对压缩比和压缩速度的要求,并证明了该算法的可行性。 相似文献
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通过对现有图像压缩和水印技术的研究,考虑图像压缩率和图像恢复的容错能力,提出了一种基于分形图像压缩编码的整数小波图像水印技术.水印嵌入时,用分形压缩编码技术对灰度水印图像进行高效压缩,再把压缩编码嵌入到载体图像的整数小波系数里,实现了在数字图像整数小波变换域中水印的大容量无损嵌入.根据提取算法,盲提取水印图像的分形编码,分形解压缩获得水印图像.经过实验验证,本水印技术具有较好的数据压缩和隐蔽性能,达到预期的设计目的. 相似文献
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嵌入式零树编码在天气雷达回波数据压缩中的应用 总被引:1,自引:0,他引:1
本文研究基于小波零树编码的天气雷达立体扫描数据压缩算法。根据雷达回波数据的特点,提出了一种有效的雷达数据预处理方案,然后利用Shapiro的嵌入式小波零树算法对预处理后的图像数据进行压缩实验。实验结果表明,该雷达回波数据压缩算法,在低比特率情况下,仍有很高的PSNR值和满意的主观效果。 相似文献
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就静止图像数据压缩编码方法进行了研究,在传统零树编码算法的基础上,提出了改进的基于小波零树编码并结合视觉加权的图像压缩算法.该改进算法充分利用了小波变换后各子带系数对图像恢复的重要程度和人眼的视觉特性,取得了良好的压缩效果和视觉效果,并通过实验证明了算法的有效性. 相似文献
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李柏岩 《计算机应用与软件》2001,18(1):62-67
本文在著名的LZW数据压缩算法基础上,提出一种新的数据压缩算法。新算法以对已压缩过的数据进行历史分析为手段,采用三个编码器对源数据序列分类编码。该算法适用压缩各种类型的数据,完全兼容LZW算法,并在平均压缩率方面较后者有较大的提高。 相似文献
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在医学研究中会产生大量需要储存、传输的图像数据,如计算机断层扫描(CT)等.医院要处理海量患者的所有数据相当困难,必须对这些数据进行压缩.随着人工智能技术的发展,应用机器学习的医学图像数据压缩方法成为新的研究热点.文中首先总结了传统医学图像数据压缩方法;然后基于机器学习的医学图像数据压缩方法,对各类方法针对脑部CT、肺部CT等不同医学图像的压缩效果进行对比,并对这些方法在压缩率、算法复杂度、重构质量等方面的优缺点进行系统的总结,指出机器学习和感兴趣区域结合的方法可以在享受有损压缩带来的高压缩率的同时保留重要区域的特征信息,比其他压缩方法更贴合医学数据的压缩要求;最后展望了该领域的未来方向和挑战. 相似文献
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On a method of binary-picture representation and its application to data compression 总被引:1,自引:0,他引:1
A method of representing a binary pictorial pattern is developed. Its original idea comes from a sequence of terminal symbols of a context-free grammar. It is a promising technique of data compression for ordinary binary-valued pictures such as texts, documents, charts, etc. Fundamental notions like complexity, primitives, simplifications, and other items about binary-valued pictures are introduced at the beginning. A simple context-free grammar G is also introduced. It is shown that every binary-valued picture is interpretable as a terminal sequence of that G. The DF-expression is defined as the reduced terminal sequence of G. It represents the original picture in every detail and contains no surplus data for reproducing it. A quantitative discussion about the total data of a DF-expression leads to the conclusion that any binary-valued picture with complexity less than 0.47 is expressed by the DF-expression with fewer data than the original ones. The coding algorithm of original data into the DF-expression is developed. It is very simple and recursively executable. Experiments were carried out using a PDS (photo digitizing system), where test pictures were texts, charts, diagrams, etc. with 20 cm × 20 cm size. Data compression techniques in facsimile were also simulated on the same test pictures. Throughout these studies it was made clear that the DF-expression is a very effective technique as a data compression for binary pictorial patterns not only because it yields high data compression but also because its coding and decoding algorithms are very feasible. 相似文献
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针对气象传真图,提出一种基于Contourlet变换的图像增强方法。充分考虑气象传真图的自身特征和Contourlet变换系数的稀疏性,应用Contourlet变换将包含噪声的图像分解成噪声系数和信号系数,利用气象传真图的主要稀疏系数对分解图像进行增强处理。实验结果表明,该方法是一种有效的气象传真图像增强方法。 相似文献
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四类机码是传真通信中一种高压缩比的信源码,目前已被广泛采用.在接收端,由于传输信道噪声影响或是接收手段不同,有时会产生传输误码.由于没有线同步码,在译码过程中一旦出现误码,即使是一比特错误,也可能产生严重的误码扩散,导致后续报文无法恢复.针对随机错误和突发错误的滑动窗口纠错译码技术,能够有效地纠正窗口范围内的多比特错误.在误码较严重而无法纠正时,重新同步技术,可有效控制误码扩散,提高报文恢复质量. 相似文献
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Various picture compression schemes are proposed which achieve a reduction in the capacity of refresh storage by exploiting the redundancy in computer graphic pictures. Many different types of compression scheme have previously been considered, particularly for facsimile transmission of black and white pictures. This paper studies a compression scheme which takes into account the two dimensional nature of computer graphic pictures and which are digitized into more than two grey levels. A practical implementation of the method is also proposed for a real time computer display system. 相似文献
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Analysis of Compressed Document Images for Dominant Skew, Multiple Skew, and Logotype Detection 总被引:1,自引:0,他引:1
A.Lawrence Spitz 《Computer Vision and Image Understanding》1998,70(3):321-334
Among the most commonly used compression algorithms for document images are those defined by the Consultative Committee for International Telephone and Telegraph (CCITT). CCITT Group III compression is used in all facsimile transmission by modem over analog telephone lines. CCITT Group IV is used in digital transmission and storage of document images. Sufficient readily interpretable spatial information exists in these compressed document images to enable their characterization. In particular, it is possible to locate the positions of the bottoms of both black and white structures. Using the bottoms of black structures we can determine the peak strength of their alignment in order to determine the dominant skew angle of the image. This method can be expanded, by finding minor peaks, to identify multiple skew angles in single images. The angular distributions of the peak alignments of both white and black structures are assembled to form an alignment signature. Logotypes can be designed which generate distinct alignment signatures that are detectable in the compressed representation. 相似文献
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《CVGIP: Graphical Models and Image Processing》1994,56(4):352-356
This paper proposes a method for identifying the existence of bar codes in compressed images without any decompression. The compressed images considered here are produced by the CCITT Group 4 (or 2-D coding in Group 3) facsimile compression standard. The proposed method is tested against forms, with Code 39 bar codes, and the results of our experiments show the method is very effective and robust against different form types and for scanning imperfection. 相似文献
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基于无线通信网络的G3传真终端的实现 总被引:1,自引:1,他引:1
无线通信技术已经广泛应用于社会各个方面,无线传真业务更是扩展了无线通信技术的应用范围。本文介绍了传真业务在CDMA,GSM等无线网络中的实现,设计了基于GSM的无线传真通信规程以及无线传真终端,并通过实验完成了无线传真的接收与发送,收到了满意的效果。 相似文献
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本文提出了模M多维差分变换的图象表示和压缩方法.变换是在对N维图象数组的2~N元分割所产生的2~N元树上进行,其效果是利用了图象的N维数据相关性,使得图象灰度值分布得到了显著的改善,它既适合于二值图象,也适合于多值图象,对于线图、文本以及具有块状或体状的图象或数组尤为有效,变换算法的复杂度非常简单,并且是递归可执行的。 相似文献