Description: Image Compression
A collection of simple routines for image compression using different techniques.
图象压缩的不同方法
BTCODE:
Image compression Using Block Truncation Coding.
PYRAMID:
Image compression based on Gaussian Pyramids.
DCTCOMPR:
Image compression based on Discrete Cosine Transform.
IMCOMPR:
Image compression based on Singular Value Decomposition.
The given codes can be also used in 2D noise suppression.
Notes:
The function \"conv2fft\" performs a 2D FFT-based convolution.
Type \"help conv2fft\" on Matlab command window for more informations. Platform: |
Size: 10228 |
Author:王云云 |
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Description: VC编写的高效的图象2D快速傅立叶正变换程序,编译通过.适合256色bmp图象变换.效果和matlab的fft2()没法比,但是程序值得借鉴.适合图象处理初学者,有助于理解傅立叶变换在图象处理中的重要作用.-VC efficient preparation of the image is 2D fast Fourier transform procedures compile. Bmp for 256-color image transformation. Results and Matlab fft2 () no match for, but the procedure is worth learning from. Image processing for beginners, helps to understand Fourier transform in the image processing an important role. Platform: |
Size: 84992 |
Author:李安定 |
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Description: 本实验要求开发一个2-D FFT程序包，使其可以应用于后续的几个实验。这个程序需要完成的功能是用因子（-1）^(x+y)乘以输入图像以实现滤波的中心变换，并还要求用一个实矩阵乘以一个复数矩阵通过调用两个图像的乘法程序来实现对应元素的相乘，同时计算反傅立叶变换，得到的结果乘以（-1）^(x+y)并取其实部最后计算频谱。实验中用到傅立叶变换的基本公式，通过实验我们可以更加深刻的理解频域滤波的基础。-The experiment calls for the development of a 2-D FFT package so that it can be applied to a number of follow-up experiment. This process needs to be done is to factor the function (-1) ^ (x+ y) multiplied by the input image to achieve the center of filter change, and also requires a real matrix multiplied by a complex matrix by calling the two images of the multiplication process to achieve multiplication of the corresponding elements, calculating the anti-Fourier transform at the same time, the result multiplied by (-1) ^ (x+ y) and check the final calculation of the Department of the spectrum in fact. Fourier transform experiment used the basic formula, we can experiment more profound understanding of the basis of frequency domain filtering. Platform: |
Size: 142336 |
Author:jhm |
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Description: Presently FFT usage in GPS receivers has been a
topic of extensive study and many improved FFT-based
acquisition methods with averaging correlation
technique also have emerged. Although averaging
arithmetic can reduce the instant processing points of
FFT/IFFT, their noise performance is not promising. In
this paper a novel compress-sampling algorithm for
FFT-base GPS signal acquisition method is proposed.
It not only diminishes the size of FFT/IFFT core but
also enhances the noise immunity of receiver with its
“redundancy” structure. Simulation results of Matlab
testify that the computational complexity of the novel
algorithm has been efficiently suppressed to only
0.93 over the 2D search method in time domain. At
the same time the lower amplitude threshold obtained
from the novel method gets a lower false alarm
probability comparing with the direct DFT algorithm
with no compression. The noise immunity is enhanced-Presently FFT usage in GPS receivers has been a
topic of extensive study and many improved FFT-based
acquisition methods with averaging correlation
technique also have emerged. Although averaging
arithmetic can reduce the instant processing points of
FFT/IFFT, their noise performance is not promising. In
this paper a novel compress-sampling algorithm for
FFT-base GPS signal acquisition method is proposed.
It not only diminishes the size of FFT/IFFT core but
also enhances the noise immunity of receiver with its
“redundancy” structure. Simulation results of Matlab
testify that the computational complexity of the novel
algorithm has been efficiently suppressed to only
0.93 over the 2D search method in time domain. At
the same time the lower amplitude threshold obtained
from the novel method gets a lower false alarm
probability comparing with the direct DFT algorithm
with no compression. The noise immunity is enhanced Platform: |
Size: 254976 |
Author:zohreh |
Hits:
Description: Presently FFT usage in GPS receivers has been a
topic of extensive study and many improved FFT-based
acquisition methods with averaging correlation
technique also have emerged. Although averaging
arithmetic can reduce the instant processing points of
FFT/IFFT, their noise performance is not promising. In
this paper a novel compress-sampling algorithm for
FFT-base GPS signal acquisition method is proposed.
It not only diminishes the size of FFT/IFFT core but
also enhances the noise immunity of receiver with its
“redundancy” structure. Simulation results of Matlab
testify that the computational complexity of the novel
algorithm has been efficiently suppressed to only
0.93 over the 2D search method in time domain. At
the same time the lower amplitude threshold obtained
from the novel method gets a lower false alarm
probability comparing with the direct DFT algorithm
with no compression. The noise immunity is enhanced-Presently FFT usage in GPS receivers has been a
topic of extensive study and many improved FFT-based
acquisition methods with averaging correlation
technique also have emerged. Although averaging
arithmetic can reduce the instant processing points of
FFT/IFFT, their noise performance is not promising. In
this paper a novel compress-sampling algorithm for
FFT-base GPS signal acquisition method is proposed.
It not only diminishes the size of FFT/IFFT core but
also enhances the noise immunity of receiver with its
“redundancy” structure. Simulation results of Matlab
testify that the computational complexity of the novel
algorithm has been efficiently suppressed to only
0.93 over the 2D search method in time domain. At
the same time the lower amplitude threshold obtained
from the novel method gets a lower false alarm
probability comparing with the direct DFT algorithm
with no compression. The noise immunity is enhanced Platform: |
Size: 87040 |
Author:zohreh |
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Description: How to apply the 2D FFT functions in Matlab
如何使用MATLAB中的FFT2对图像进行二维的FFT处理详细教程-How to apply the 2D FFT functions in Matlab
如何使用MATLAB中的FFT2对图像进行二维的FFT处理详细教程 Platform: |
Size: 7168 |
Author:xuyutong |
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Description: This is the processing of images to be converted into 2D. from the original picture, it will be first converted to grayscale in the form, then do 2 Dimensional FFT on the image, then the image is done in 2D FFT on the result of changes filter.seluruh images displayed. Platform: |
Size: 1024 |
Author:azmi |
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Description: 这是一个简单的FFT为无电位1 +1 +1 Ð 薛定谔方程的光束传播方法。如果该软件灵活，允许引入的术语（如果是极少数需要包括色散效应高阶导数）。例如，如果一个人渴望解决的一个方程的形式：
（四/ dz的+ Ð ^ 2/dx ^ 2 - 0.25 * Ð ^ 3/dx ^ 3）== 0 Ÿ
它可以解决使用以下代码：
Ž = linspace（0,1,512）
x = linspace（-5,5,1024）
psi0 =进出口（- x的。^ 2）
Ð = D_lateral1D（十，2）-0.25 * D_lateral1D（十，3）
字段= LinearBPM（psi0，有D，Z）
凡D_lateral1D是一个函数，提供“取代”的微分算子。
这个函数是在一个非线性的BPM，我曾对（分步，谱方法等），将提交给我，当我完成他们的文件和组织功能更复杂的设置非常初期阶段。
-This is a simple FFT based beam propagation method for potential-free 1+1+1D Schrodinger equation. The software if flexible and allows to introduce high-order derivatives in the term (very handful if is needed to include dispersion effects). For example, if one desires to solve an equation in the form:
(d/dz+ d^2/dx^2- 0.25*d^3/dx^3)Y == 0
It can be solved using the following code:
z=linspace(0,1,512)
x=linspace(-5,5,1024)
psi0=exp(-x.^2)
D=D_lateral1D(x,2)-0.25*D_lateral1D(x,3)
field=LinearBPM(psi0,D,z)
Where D_lateral1D is a provided function that "replaces" the derivative operator.
This function is a very early stage in a more complex set of non-linear BPM functions that I have made (split-step, spectral methods, etc.) and I will submit them when I finish their documentation and organization.
Sorry for my English, I m eager for your comments.
Platform: |
Size: 2048 |
Author:zhou |
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Description: 一系列展示图像压缩技术的源代码。包括有：使用块截断编码的图像压缩(Block Truncation)、基于高斯金字塔变换的图像压缩(Gaussian Pyramids)、基于离散余弦变换对图像压缩(Discrete Cosine Transform)、基于奇异值分解(SVD)的图像压缩(Singular Value Decomposition)。给出的代码还可以用于2D图像噪声消除。-Image Compression
A collection of simple routines for image compression using different techniques.
BTCODE:
Image compression Using Block Truncation Coding.
PYRAMID:
Image compression based on Gaussian Pyramids.
DCTCOMPR:
Image compression based on Discrete Cosine Transform.
IMCOMPR:
Image compression based on Singular Value Decomposition.
The given codes can be also used in 2D noise suppression.
Notes:
The function "conv2fft" performs a 2D FFT-based convolution.
Type "help conv2fft" on Matlab command window for more informations. Platform: |
Size: 56320 |
Author:依米 |
Hits:
Description: Matlab动力系统和时间序列分析工具箱:这个工具箱用来分析动力系统和时间序列，它可以定制为：常微分方程、随机微分方程。所有分析的方法被封装在工具箱中，你可以通过命令行或GUI来调用。包含的功能：
ODE常微分方程, SDE随机微分方程和map integration 分析时间序列，过滤、归一化/均衡化、直方图、2D直方图、ACF, MAI, FFT,最大lyapunov指数计算、模式识别。
动力系统分析：创建Poincare截面、分岔图、计算lyapunov指数。-The kit used to analyze the power systems and time series, it can be customized as: ordinary differential equations, stochastic differential equations. All analysis methods are encapsulated in the toolbox, you can call the command line or GUI. Includes features: ODE ordinary differential equation, SDE Stochastic Differential Equations and map integration analysis of time series, filtering, normalization/equalization, histogram, 2D histogram, ACF, MAI, FFT, the maximum lyapunov index, pattern recognition . Power System Analysis: Creating Poincare section, bifurcation diagrams, calculations lyapunov index. Platform: |
Size: 381952 |
Author:朱凤宇 |
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Description: 二维傅里叶变换,对图像进行二维傅里叶变换处理-Two-Dimensional Fast Fourier Transform
The purpose of this project is to develop a 2-D FFT program "package" that will be used
in several other projects that follow. Your implementation must have the capabilities to:
(a) Multiply the input image by (-1)x+y to center the transform for filtering.
(b) Multiply the resulting (complex) array by a real function (in the sense that the
the real coefficients multiply both the real and imaginary parts of the transforms).
Recall that multiplication of two images is done on pairs of corresponding elements.
(c) Compute the inverse Fourier transform.
(d) Multiply the result by (-1)x+y and take the real part.
(e) Compute the spectrum. Platform: |
Size: 1024 |
Author:solo |
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Description: Pass the Images Through Optics -- Use a Gaussian "Aperture Function"
This code segement can use a measured aperture function just as easily - simply replace the next five lines by "load measured_aperture" where measured_aperture is the measured function strored in ASCII and the data stored in the file measured_aperture.mat is a MATLAB .mat file that contains the matrix apfunction. (in MATLAB type "help load" for how to use load and look at the c and fortran code that shows how to read and write MATLAB .mat files).
(Note: When the Point Spread Function is Gaussian, then so is the Aperture function)
To simulate the effect of the tracker optics, each of the movie frames is now blurred using a 2-D FFT (Fast Fourier Transform). The first frame of the resulting image is shown in Figure 1.
- Pass the Images Through Optics -- Use a Gaussian "Aperture Function"
This code segement can use a measured aperture function just as easily - simply replace the next five lines by "load measured_aperture" where measured_aperture is the measured function strored in ASCII and the data stored in the file measured_aperture.mat is a MATLAB .mat file that contains the matrix apfunction. (in MATLAB type "help load" for how to use load and look at the c and fortran code that shows how to read and write MATLAB .mat files).
(Note: When the Point Spread Function is Gaussian, then so is the Aperture function)
To simulate the effect of the tracker optics, each of the movie frames is now blurred using a 2-D FFT (Fast Fourier Transform). The first frame of the resulting image is shown in Figure 1.
Platform: |
Size: 1024 |
Author:sabah_altaie |
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Description: 2D FFT and 2D IFFT in matlab. inputs are original data and block size. ex) block size = [8 8] Platform: |
Size: 231424 |
Author:nishina |
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Description: 基于MATLAB实现了极坐标下的傅里叶变换，对一个给定 n×n 的二维信号，其计算复杂度等价于笛卡尔坐标下的2D-FFT，可广泛应用于图像处理和分析。-A fast high accuracy Polar FFT algorithm is given in the software package written in MATLAB. For a given 2D signal of size n×n, the algorihtm s complexity is just like in a Cartesian 2D-FFT, which can be used widely in image processing and analysis. Platform: |
Size: 579584 |
Author:周清保 |
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Description: Image Compression
A collection of simple routines for image compression using different techniques.
BTCODE:
Image compression Using Block Truncation Coding.
PYRAMID:
Image compression based on Gaussian Pyramids.
DCTCOMPR:
Image compression based on Discrete Cosine Transform.
IMCOMPR:
Image compression based on Singular Value Decomposition.
The given codes can be also used in 2D noise suppression.
Notes:
The function conv2fft performs a 2D FFT-based convolution.
Type help conv2fft on MATLAB command window for more informations.-Image Compression
A collection of simple routines for image compression using different techniques.
BTCODE:
Image compression Using Block Truncation Coding.
PYRAMID:
Image compression based on Gaussian Pyramids.
DCTCOMPR:
Image compression based on Discrete Cosine Transform.
IMCOMPR:
Image compression based on Singular Value Decomposition.
The given codes can be also used in 2D noise suppression.
Notes:
The function conv2fft performs a 2D FFT-based convolution.
Type help conv2fft on MATLAB command window for more informations. Platform: |
Size: 9216 |
Author:keyvan |
Hits:
Description: MATLAB中的雷达目标生成和检测,调频连续波,FFT（用于范围检测的1D）,FFT (2D for distance and speed detection),2d恒定火焰警报率（2D-CFAR）(Radar target generation and detection in MATLAB, FM continuous wave, FFT (1D for range detection), FFT (2D for distance and speed detection), 2d constant flame alarm rate (2D-CFAR)) Platform: |
Size: 648192 |
Author:黛汐520 |
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Search - fft in 2d matlab