Landsat-TM光谱图像数据压缩技术的研究

采用提升格式的整数小波变换，对Landsat-TM图像数据进行小波分解。在分析Landsat-TM图像整数小波变换后系数特点的基础上，将小波变换压缩技术中的零数编码推广到多光谱图像压缩中。采用整数97小波变换同时去除空间与谱间冗余，对单波段图像各个子带小波系数的能量、均值、方差进行了数据统计。由小波系数的相关性，采用3DSPIHT对小波系数进行压缩编码。实验结果表明，该方法的去相关性能良好，压缩效果大大改善。     

基于提升整数小波变换的虹膜识别

提出了一种基于小波提升方案的虹膜识别算法。与传统基于卷积的小波变换方法相比,该方法在特征提取上计算简单,运算速度快,而且实现的是从整数到整数的变换,更有利于虹膜信息的量化。先对虹膜图像进行提升整数小波变换,然后对子图进行量化编码得到特征,采用屏蔽了噪声位的汉明距来进行模式识别。实验结果表明,基于提升整数小波变换的虹膜识别方法在识别率和等错率方面都能达到好的识别效果,在特征提取速度上也得到了较大提升,更能满足实时性的要求。     

基于提升方案的整数Deslauriers—Dubuc（m,n）插值小波变换结合SPIHT应用于图象无损压缩性能的研究

研究了基于提升方案的Deslauriers-Dubuc(m,n）插值小波变换结合SPIHT应用于图象无损压缩编码的性能，实验结果表明，基于提升方案和整数运算的插值小波变换是整－整可逆变换，适于快速的，渐进性的直至无损图象压缩，无损压缩性能远好于Huffman,WinRar,Raw WinZip,JPEGLS,以（4，4）插值小波为例平均而言压缩比较分别比上述编码方法提高了63％、49％、46％，34％左右，由于实现的可逆小波变换是基于整数运算的，可由加法和移位完成，运算速度快，便于运态图象编码及硬件实现。     

动态心脏超声波序列图像压缩的脊波方法

在介绍脊波理论的基础上,采用平行束投影(Radon变换)加整数小波变换的方法来实现脊波变换,以此为基础设计出一种压缩方案,并将其应用到动态心脏超声波序列图像的压缩中。由于平行束投影对噪声具有抑制作用,整数小波变换可以节约系数的存储空间,因此在相同的压缩环境下,与直接用2-D整数小波变换进行压缩相比,文中的方法能得到更大的压缩比。编码脊波系数时,提出按投影分度方向来组织和预测脊波系数的思想,使得该方法在实现嵌入式编码的同时还具有了较强的鲁棒性。文中的方法可用于远程医疗、CT、MRI和视频压缩等领域。     

基于提升方案的整数Deslauriers-Dubuc(m,n)插值小波变换结合SPIHT应用于图象无损压缩编码性能的研究

研究了基于提升方案的 Deslauriers- Dubuc( m ,n)插值小波变换结合 SPIHT应用于图象无损压缩编码的性能 .实验结果表明 ,基于提升方案和整数运算的插值小波变换是整 -整可逆变换 ,适于快速的 ,渐进性的直至无损图象压缩 .无损压缩性能远好于 Huffm an、Win Rar、Raw Win Zip、JPEGL S.以 ( 4,4)插值小波为例平均而言压缩比分别比上述编码方法提高了 63 % ,49% ,46% ,3 4%左右 .由于实现的可逆小波变换是基于整数运算的 ,可由加法和移位完成 ,运算速度快 ,便于动态图象编码及硬件实现     

整数小波变换和EZW编码在基于ROI图像渐进传输中应用研究

整数小波变换能够克服浮点数小波变换所带来的缺陷,是一种真正意义上的无损可逆小波变换,基于整数小波变换的EZW编码是一种嵌入式编码技术,能够有效地应用于图像的压缩与渐进传输.介绍了整数小波变换和EZW编码的工作原理,然后将它们应用于ROI图像压缩与渐进传输,并给出了实验结果.     

基于改进提升小波变换SPIHT的图像压缩算法

通过对提升小波变换的SPIHT算法进行改进和优化,提出了一种适用于无线多媒体传感器网络(WMSNs)的简单、高效、节能的有损图像压缩算法;该算法采用只包含加法和移位操作的整数小波提升算法,使得小波分解的计算量减半,大大提高了变换速度;采用量化截断的预处理技术,省去大量不重要高频系数的量化编码,解决了提升变换后SPIHT算法编码效率低的问题;去除了最外层高频系数的分解和编码,有效地减少了变换和编码的能耗;理论分析和仿真结果均表明,在保证一定重建图像质量的前提下,该算法大大降低了图像压缩能耗,提高了算法的压缩效率和执行效率,非常适合于资源受限的WMSNs中的图像压缩。     

一种高效的数字笔迹多维数据编码算法

提出了一种高效的数字笔迹数据编码算法IWPHSP(integer wavelet packet based hierarchical set partitioned).该算法通过引入整数小波包变换、层次性集合分裂、重要位组合编码和快速自适应算术编码等方法,无损地压缩了数字笔迹多维数据.实验证明,提出的IWPHSP算法是高效的.     

基于最佳补偿比例因子的整数小波变换

为了提高提升格式下整数小波变换的有损压缩性能,提出了基于最佳补偿比例因子的优化算法。根据变换后小波系数和滤波器的特性,分别采用子带近似线性逼近和量化补偿噪声取代取整运算的方法,求得小波分解后各个子带的最佳补偿比例因子。利用这个比例因子补偿整数小波变换的非线性带来的近似误差以达到优化目的。实验结果表明,在不增加运算复杂度的情况下,所得压缩图像的峰值信噪比(PSNR)与基于浮点运算的传统离散小波变换几乎一样。     

动态心脏超声波序列图像压缩的脊波方法

在介绍脊波理论的基础上，采用平行束投影（Radon变换）加整数小波变换的方法来实现脊波变换，以此为基础设计出一种压缩方案，并将其应用到动态心脏超声波序列图像的压缩中。由于平行束投影对噪声具有抑制作用，整数小波变换可以节约系数的存储空间，因此在相同的压缩环境下，与直接用2-D整数小波变换进行压缩相比，文中的方法能得到更大的压缩比。编码脊波系数时，提出按投影分度方向来组织和预测脊波系数的思想，使得该方法在实现嵌入式编码的同时还具有了较强的鲁棒性。文中的方法可用于远程医疗、CT、MRI和视频压缩等领域。     

A chronological and mathematical overview of digital circle generation algorithms – introducing efficient 4- and 8-connected circles

Circles are one of the basic drawing primitives for computers and while the naive way of setting up an equation for drawing circles is simple, implementing it in an efficient way using integer arithmetic has resulted in quite a few different algorithms. We present a short chronological overview of the most important publications of such digital circle generation algorithms. Bresenham is often assumed to have invented the first all integer circle algorithm. However, there were other algorithms published before his first official publication, which did not use floating point operations. Furthermore, we present both a 4- and an 8-connected all integer algorithm. Both of them proceed without any multiplication, using just one addition per iteration to compute the decision variable, which makes them more efficient than previously published algorithms.     

An interior point cutting plane heuristic for mixed integer programming

We explore the use of interior point methods in finding feasible solutions to mixed integer programming. As integer solutions are typically in the interior, we use the analytic center cutting plane method to search for integer feasible points within the interior of the feasible set. The algorithm searches along two line segments that connect the weighted analytic center and two extreme points of the linear programming relaxation. Candidate points are rounded and tested for feasibility. Cuts aimed to improve the objective function and restore feasibility are then added to displace the weighted analytic center until a feasible integer solution is found. The algorithm is composed of three phases. In the first, points along the two line segments are rounded gradually to find integer feasible solutions. Then in an attempt to improve the quality of the solutions, the cut related to the bound constraint is updated and a new weighted analytic center is found. Upon failing to find a feasible integer solution, a second phase is started where cuts related to the violated feasibility constraints are added. As a last resort, the algorithm solves a minimum distance problem in a third phase. The heuristic is tested on a set of problems from MIPLIB and CORAL. The algorithm finds good quality feasible solutions in the first two phases and never requires the third phase.     

Integer Matrix Approximation and Data Mining

Integer datasets frequently appear in many applications in science and engineering. To analyze these datasets, we consider an integer matrix approximation technique that can preserve the original dataset characteristics. Because integers are discrete in nature, to the best of our knowledge, no previously proposed technique developed for real numbers can be successfully applied. In this study, we first conduct a thorough review of current algorithms that can solve integer least squares problems, and then we develop an alternative least square method based on an integer least squares estimation to obtain the integer approximation of the integer matrices. We discuss numerical applications for the approximation of randomly generated integer matrices as well as studies of association rule mining, cluster analysis, and pattern extraction. Our computed results suggest that our proposed method can calculate a more accurate solution for discrete datasets than other existing methods.     

一种基于整数小波变换的图像无损压缩方法

由于第二代小波变换可以实现图像的整数到整数的变换,而且图像的恢复质量与变换时边界采用何种延拓方式无关,完全可以克服由第一代小波变换所带来的缺陷。该文利用这个特性,提出了一种基于整数小波变换的图像无损压缩算法。该方法首先将图像进行整数小波变换,然后利用不同子带的小波系数分布特性,对不同的子带采用不同的预测方式,最后将预测误差进行哈夫曼编码。实验结果表明,该方法算法简单,有较好的压缩性能,与JPEG无损压缩模式相比较,有较大的优势。     

Integral Approximation of Rays and Verification of Feasibility

An algorithm is presented that produces an integer vector nearly parallel to a given vector. The algorithm can be used to discover exact rational solutions of homogeneous or inhomogeneous linear systems of equations, given a sufficiently accurate approximate solution.As an application, we show how to verify rigorously the feasibility of degenerate vertices of a linear program with integer coefficients, and how to recognize rigorously certain redundant linear constraints in a given system of linear equations and inequalities. This is a first step towards the handling of degeneracies and redundandies within rigorous global optimization codes.     

A computational comparison of gomory and knapsack cuts

A common method of solving integer programs is to solve the problem first as a linear program (LP) then add constraints that cut off noninteger solutions from the set of LP feasible solutions. As soon as an optimal LP solution is all integer, then it is an optimal solution to the integer program. The method of Gomory can generate a variety of different cuts but there is a dearth of reports on systematic testing of the effectiveness of different cuts. We report extensive computational comparisons between a number of different cuts, including a successful one not previously publicised. It has been known for some time that Gomory cuts can be unsuccessful because of slow convergence with the accompanying difficulties of computer round-off error. Recently a method has been proposed for generating, for 0–1 integer problems, cuts that are usually tighter than Gomory cuts and thus give faster convergence. This method of knapsack cuts is tested in comparison with Gomory cuts for moderate size problems and is found to be superior for 0–1 problems having dense constraint matrices but only slightly better than Gomory cuts for problems with sparse matrices. On the other hand, knapsack cuts applied to general integer problems reformulated as 0–1 are found to be less successful than Gomory cuts applied to the original integer problem.     

基于9-7整数小波变换的SPIHT的改进

对SPIHT进行了研究，提出了基于9-7整数小渡变换的改进的SPIHT。它首先对图像进行整数小渡分解，然后对低频子带图像采用DPcM预测编码，对高频子带改变扫描方式来获得最大系数和按照频率优先的原则输出系数。实验结果表明算法在相同的输出码率情况下不仅得到了更好的恢复效果，而且缩短了编码时间。     

整数变换实现大容量图像无损信息隐藏

目的 针对图像无损信息隐藏中嵌入容量和隐藏图像质量问题,描述了一种基于可逆整数变换算法在图像中实现较大容量数据嵌入的无损隐藏方法。方法 定义的可逆整数变换算法先计算图像块n个像素点的整数平均值,在整数变换过程中将各像素点与平均值之间的差值扩展到4倍。结果 整数变换后图像块所有像素点最低两位有效位相同,产生的冗余信息可用来嵌入2(n-1)比特数据。结论 给出了一种新的可逆整数变换算法并实现较大容量图像无损信息隐藏,实验结果表明该方法具有较大的数据嵌入容量和较好的隐藏图像质量,嵌入数据和原宿主图像均能从隐藏图像中无失真恢复。     

基于格的高效通用累加器与被累加值的零知识证明

通用累加器作为一种具有数据压缩性质的重要密码学元件,其多应用于隐私保护相关的区块链系统、身份认证系统以及各类权限管理系统。研究发现目前已有的基于小整数解（SIS）问题困难性假设的通用累加器内部计算效率不高,且更新效率低。因此,本文设计并实现了首个基于环小整数解（Ring-SIS）问题困难性假设的高效通用累加器,其更新开销在平均意义上远低于以往方案,更加适用于更新操作频繁,成员数量更庞大的应用场景。另外针对Ring-SIS通用累加器内的所有成员,本文基于Schnorr-like协议框架提出了首个单轮次执行合理性错误可忽略的被累加值的零知识证明协议。     

集装箱堆场预倒箱问题的混合优化算法

堆场出口箱区通常通过集装箱的预倒箱操作来提高后续装船作业的效率. 为此, 开发了由邻域搜索算法与整数规划算法组成的两阶段混合算法对预倒箱问题进行优化, 第1 阶段通过启发式规则压缩末终堆存状态空间, 第2 阶段通过整数规划算法缩短第1 阶段得到的预倒箱序列的长度. 两个阶段循环交替进行以快速求得最优的预倒箱序列. 借助不同种类仿真算例的实验结果及与现有研究方法下所得结果的对比, 验证了混合优化算法的有效性和实用性.