查询词典 Fourier cosine transform

Adaptive filtering ; time-domain LMS ; discrete Fourier transform ; discrete cosine transform ; discrete wavelet transform

自适应滤波；时域LMS ；离散Fourier变换；离散余弦变换；小波变换

The JPEG standard algorithm ; arithmetic fourier transform; discrete cosine transform; fast discrete cosine transform

JPEG标准算法；算术傅立叶变换；离散余弦变换；快速离散余弦变换

In this paper, an improved technique of static image compression is completed based on the JPEG standard, the technique uses a new Fourier analysis technique called the arithmetic Fourier transform to compute discrete cosine transform coefficient.

本文在国际标准组织制定的静态图像压缩标准JPEG的基础上，提出了一种采用新的傅立叶分析技术—算术傅立叶变换来快速计算离散余弦变换系数值，改进了静态图像压缩技术，克服了DCT运算速度慢的缺点，同时克服了传统的快速离散余弦变换程序复杂，子进程多的缺点。

in order to simplify a process of getting parameters of daubechies biorthonormal wavelet, according to the fourier cosine transform of scale equation of daubechies biorthonormal wavelet, an algorithm is proposed when the daubechies biorthonormal wavelet has even symmetry double scale parameters.

摘 要：为简化daubechies双正交小波因数的求解，以紧支集daubechies正交小波中尺度关系的fourier变换余弦形式为基础，提出1种当双尺度因数为偶对称时，推导daubechies双正交小波对偶尺度方程因数的方法，并给出构造数值实例。

The exact solutions are then obtained for the equations characterizing flows of such fluids under an arbitrary pressure gradient by the method of integral transforms (Fourier Cosine transform and Laplace transform).

运用积分变换方法(Fourier余弦变换和Laplace变换)，求得了在任意压力梯度下流体运动方程的精确解。

It is shown that many of the existing integral transforms (including their logically equivalents) such as chirplet transform, dispersion transform, wavelet transform, chirp-Fourier transform, short-time Fourier transform, Gabor transform, Fourier transform, cosine transform, sine transform, Hartley transform, Laplace transform, z transform, Mellin transform, Hilbert transform, autocorrelation function, cross-correlation function, and the energy and mean of a signal, can each be considered as a special case of the FMmlet transform with specific parameters. In fact, an inventory of subspaces of FMmlet transform runs into countless numbers. The subspaces mentioned above are merely a few among a zoo of subspaces. They are essentially obtained by cutting the transform space of FMmlet transform at different positions, and can be likened to the computed tomography in medical diagnosis. Through these subspaces we actually see different slices or profiles of the FMmlet transform.

将现有诸多变换置于统一的 FMmlet 变换中加以审视，发现 chirplet 变换、频散变换、小波变换、 chirp-Fourier 变换、短时 Fourier 变换、 Gabor 变换、 Fourier 变换、余弦变换、正弦变换、 Hartley 变换、 Laplace 变换、变换、 Mellin 变换、 Hilbert 变换、自相关函数、互相关函数、能量和均值等，均为 FMmlet 变换在其参数取特定值时的特例；上述诸变换之间的差别，主要在于变换空间的维数有别，以及在不同空间维上取值的不同；这些变换有如医学诊断中的 CT，均由压缩 FMmlet 变换域空间所致，可以说我们通过这些变换看到的，是 FMmlet 变换的不同剖面。

Contents : Chapter 4 Image Enhancement (contrast enhancement, gray transform, histogram dressing, image smoothing, sharpening, Pseudo-color and false color enhancement); Chapter 5 of Image Restoration (inverse filter rehabilitation, Wiener filtering method); Chapter 6 of image processing orthogonal transformation Fourier transform, discrete cosine transform (DCT, the Walsh transform, Based on the eigenvectors of transformation, Hotelling transform, SVD transform, wavelet transform, Mallat algorithm; Chapter 7 Image Coding Hoffman (Huffman coding, arithmetic coding, RIc, the bit-plane coding, predictive coding, DPCM.

内容：第4章图像增强（对比度增强、灰度变换法、直方图修整法、图像平滑、图像锐化、伪彩色和假彩色增强）；第5章图像复原（逆滤波复原、维纳滤波方法）；第6章图像处理中的正交变换（傅立叶变换、离散余弦变换、沃尔什变换、基于特征向量的变换、霍特林变换、SVD变换、小波变换、Mallat算法）；第7章图像压缩编码（霍夫曼编码、算术编码、游程编码、位平面编码、预测编码、DPCM、JPEG 2000编码

In model experiments, we find that the deviation of the first derivative calculated by Fourier transform is very large to comparing with the theoretical derivative, but the fitting effect of the derivative of anomalies calculated by cosine transform is very good. The calculation accuracy of data are all very high except that errors of several data on the boundary are large because of the residual Gibbus effect induced by finite truncation of gravity anomalies. Errors are -009%～5%.

模型实验中发现，用Fourier变换计算的一阶导数与理论导数偏差很大，而余弦变换计算的导数与理论异常导数拟合效果非常好，除边界几个数据因重力异常的有限截断产生的吉布斯效应残留使误差较大外，数据的计算精度均很高，误差为-009%～5%。

The horizontal and vertical first derivatives of magnetic anomalies of an infinite cylinder are calculated by the cosine transform method, in which the maximum errors are -0.28 nT/m and 0.47nT/m, respectively and the percent errors are generally within -3.57%~3.27% and -1.94%~1.88%, respectively except several data of the boundary and part are bigger because of remains of Gibbus effect. The calculating curve and theoretical curve are approximately coincident, and there is no influence by effective magnetic dip angle in computing. But the errors with the Fourier transform method are -10.62nT/m and 14.42nT/m, there is large departure between the calculating curve and theoretical curve and evident influence by effective magnetic dip angle in computing.

利用余弦变换法计算的无限长水平圆柱体磁异常水平和垂向一阶导数的最大误差分别为-0.28nT/m、0.47nT/m；水平一阶导数的误差一般在-3.57%~3.27%之间，垂向一阶导数的误差一般在-1.94%~1.88%之间；计算的磁异常一阶导数值与理论值大致重合，而且不受有效磁化倾角的影响而Fourier变换法计算的水平和垂向一阶导数最大误差分别为-10.62nT/m、14.42nT/m，计算曲线与理论曲线偏离大，受磁化倾角的影响也较大。

For fast orthogonal transformation algorithm, the paper carries out detailed research and analysis. In terms of many transform coding, it put forward these four rapid transformation algorithms which are Discrete Cosine Transform, Discrete Fourier Transform, Harr Transform, Walsh-Handmaid Transform, and analysis of these fast algorithms in image compression applications.

对于正交变换的快速算法本文进行了详细的研究与分析，并根据各种变换编码，提出了离散余弦变换、离散傅立叶变换、Harr变换、Walsh-Hadamard变换这四种变换的快速算法，并分析了这些快速算法在图象压缩中的应用。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。