一种高吞吐率JPEG2000 9/7离散小波变换VLSI设计(英文)

为提高JPEG2000系统中离散小波变换的计算并行度,设计了一种高吞吐率二维9/7离散小波变换VLSI架构.其行变换核采用翻转结构,并根据行列变换核输入数据流的差异,在行变换核基础上增加输入选择器和数据缓存模块得到列变换核.对行列变换的归一化过程进行融合以节省乘法器,并论证了其合理性.通过多路选择器重排4个行变换核的输出,使每个列变换核处理的数据量减半,实现四路输入、四路输出.对一幅N×N的灰度图像进行一层9/7小波变换,计算时间为0.25N2+1.5N个周期,关键路径延迟为1个乘法器延迟,且只需5N存储空间.FPGA后仿真结果表明,时钟频率可达136 MHz,吞吐率达到544M sample/s,可以满足高速率应用的要求.     

基于快速离散曲波变换的图像去噪

针对软阈值和硬阈值去噪方法存在的不足,采用加权平均的思想,构造了一种基于快速离散曲波变换的新阈值函数。实验结果表明,利用新阈值函数去噪后的图像峰值信噪比明显提高,视觉效果也有较大程度的改善。     

基于小波变换的跨膜蛋白跨膜螺旋区段预测

1 Introduction In existing genome databases ,about 20 %-30 %ofgenetic products have been esti mated as encodedmembrane proteins[1]. However , about 30 % of allproteins are membrane proteins inliving cells .The TMproteins play ani mportant role especiallyi…     

Multiple descriptions based wavelet image coding

INTRODUCTIONJPEG2 0 0 0 (LawsonandZhu ,2 0 0 2 )isanewlypublishedstillimage codinginternationalstandard .Itsintroductionmeantthatforthefirsttime,thediscretewavelettransform (DWT)wouldbeusedforthedecompositionandrecon structionofimagestogetherwithanefficientcod ingscheme.IntheJPEG2 0 0 0coder,beforeanywaveletdecompositionisperformed ,theimageispartitionedintonon overlappingtiles.Thesetilesareofequalsizeexceptpossiblyforthoseadjacenttotheimageboundary .Thenwavelettransformisappliedtotr…     

离散仿射小波变换神经网络函数逼近方法

通过对仿射离散小波框架的分析,用离散仿射小波变换时频局部化集中与神经网络的有关理论,研究了前传神经网络的组织结构与简化,提出了处理方案,并利用此理论对波函数的逼近给出了一般算法．     

新的基于奇异值分解和小波变换的图像水印技术

基于传统的奇异值分解技术和小波变换技术,这里将两种技术相结合,提出了一种新的数字图像水印技术。将灰度水印图像嵌入到了载体小波变换分解后的中频子带。仿真实验结果表明,该算法比较有效,能够抵抗多种攻击,具有较好的鲁棒性和透明性。     

一种基于离散小波变换的数字水印算法

提出了一种基于离散小波变换的数字图像水印算法。实验结果证明,该算法不仅具有透明性、安全性和稳定性而且进行图像处理时具有较强的鲁棒性。     

Entropy of images after wavelet transform

We studied the variation of image entropy before and after wavelet decomposition, the optimal number of wavelet decomposition layers, and the effect of wavelet bases and image frequency components on entropy. Numerous experiments were done on typical images to calculate （using Matlab） the entropy before and after wavelet transform. It was verified that, to obtain minimal entropy, a three-layer decomposition should be adopted rather than higher orders. The result achieved by using biorthogonal wavelet decomposition is better than that of the orthogonal wavelet decomposition. The results are not directly proportional to the vanishing moment, however.     

Wavelet packet decomposition entropy threshold method for discrete spectrum interferences rejection of on-line partial discharge monitoring

1. Introduction For suppressing discrete spectrum interference (DSI) in partial discharge (PD) signals, the presently wide-used approaches are hardware filters and Fourier transform based digital notch filters [1], which, definitely having gained effect in some extent, lead to relatively large energy loss of original PD signals and the preset parameters wont work when new interference appears or some center frequency changes. Adaptive filters [2] adjust parameters automatically with poor st…     

Multiple description scalable video coding based on 3D lifted wavelet transform

INTRODUCTION With the expansion of multimedia applications, video transmission is becoming an important issue in the research area of communication. It is very im- portant to compress a large amount of video data effectively, which has already attracted considerable attention recently. To make source coders both er- ror-resilient and network-adaptive are two main challenges facing the video compression techniques. It is necessary to make the bitstreams temporal, spa- tial and SNR scalabl…     

A data-mining approach to biomarker identification from protein profiles using discrete stationary wavelet transform

Objective: To develop a new bioinformatic tool based on a data-mining approach for extraction of the most infor-mative proteins that could be used to fred the potential biomarkers for the detection of cancer. Methods: Two independent datasets from serum samples of 253 ovarian cancer and 167 breast cancer patients were used. The samples were examined by surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF MS). The datasets were used to extract the informative proteins using a data-mining method in the discrete stationary wavelet transform domain. As a dimensionality re-duction procedure, the hard threshoiding method was applied to reduce the number of wavelet coefficients. Also, a distance measure was used to select the most discriminative coefficients. To find the potential biomarkers using the selected wavelet coefficients, we applied the inverse discrete stationary wavelet transform combined with a two-sided t-test. Results: From the ovarian cancer dataset, a set of five proteins were detected as potential biomarkers that could be used to identify the cancer patients from the healthy cases with accuracy, sensitivity, and specificity of 100%. Also, from the breast cancer dataset, a set of eight proteins were found as the potential biomarkers that could separate the healthy cases from the cancer patients with accuracy of 98.26%, sensitivity of 100%, and specificity of 95.6%. Conclusion: The results have shown that the new bioinformatic tool can be used in combination with the high-throughput proteomic data such as SELDI-TOF MS to find the potential biomarkers with high discriminative power.     

基于自适应双正交局部离散余弦变换的直接序列扩频通信干扰抑制技术

A novel time-frequency domain interference excision technique is proposed. The technique is based on adaptive biorthogonal local discrete cosine transform (BLDCT). It uses a redundant library of biorthogonal local discrete cosine bases and an efficient concave cost function to match the transform basis to the interfering signal. The main advantage of the algorithm over conventional transform domain excision algorithms is that the basis functions are not fixed but can be adapted to the time-frequency structure of the interfering signal. It is well suited to transform domain compression and suppression of various types of interference. Compared to the discrete wavelet transform (DWT) that provides logarithmic division of the frequency bands, the adaptive BLDCT can provide more flexible frequency resolution. Thus it is more insensitive to variations of jamming frequency. Simulation results demonstrate the improved bit error rate (BER) performance and the increased robustness of the receiver.     

Wavelets: Applications to image compression-II

We explain here, the wavelet based thresholding procedure, one of the key factors behind the successful application of wavelets in image compression. We then elaborate on quantization and go on to outline the basic ideas underlying Huffman coding, the other important tool for data compression.     

小波变换在植被格局分析中的应用

本文通过野外实地观测,利用小波理论尝试性地分析了1000m样带上植被总盖度在不同尺度下的分布特征。通过不同尺度下小波变换映像值的分析,解决了植被格局研究中在不同尺度下同时进行规模、强度、纹理分析这一久而未决的难题,发现了植被格局规模在不同尺度下的变化符合分形性质的特点。     

小波变换在图像边缘检测中的应用

提出将小波变换应用于图像边缘检测的具体算法原理,将其应用于图像边缘检测具有定位精度高、去噪效果好的优点,仿真结果表明了此方法的正确性和有效性。     

小波变换在数字图像处理中的应用

主要分析了基于小波变换的图像分解和图像压缩的技术，并运用Matlab软件对图像进行分解，然后提取其中与原图像近似的低频信息，达到对图像进行压缩的目的．分别作第一层分解和第二层分解，并比较图像压缩的效果。     

Optical encryption with cascaded fractional wavelet transforms

INTRODUCTION Recently, with the development of science andtechnology, more and more people become interestedin researching image encryption techniques. Manymethods have been proposed for optical image en-cryption. Random phase encoding methods and digi-tal holography techniques are effectively used inencrypting (Javidi and Nomura, 2000; Unnikrishnanet al., 2000a; Hennelly and Sheridan, 2003; Nishchalet al., 2004). Meantime some important properties oflight are used to realize encryptio…     

快速小波变换在MEMS陀螺信号处理中的应用

介绍了Mallat快速小波分解和重构算法,分析了一种可以大大降低运算负担,并且十分易于硬件实时实现的快速算法.该算法不再需要小波变换过程中的内插和抽取步骤,给出了相应的分解和重构过程的公式.对MEMS陀螺仪测量信号的仿真结果表明:算法只需更短的处理时间就可以完成去噪声过程,并且可以取得同样的去噪效果.在TMS320C6713芯片上实现了该算法,每个数据的处理时间只需0.014ms,静态漂移信号的标准差也从78.435 5(°) /h降到36.763 5(°) /h,完全可以满足信号实时处理的需要.     

基于小波变换的地震信号去噪方法研究

提高信噪比是地震信号数字处理的主要任务．研究了几种常用的小波去噪方法在地震信号中去除随机噪声的应用,分析了各自的特点,并改进了算法．通过MATLAB的仿真结果表明,小波变换的去噪效果明显优于传统的Fourier变换方法．