Applications Of The Two-Dimensional Fast Fourier Transform For Optical Systems Analysis

1979 ◽  
Author(s):  
William N. Peters
Keyword(s):  
Fourier Transform ◽  
Fast Fourier Transform ◽  
Systems Analysis ◽  
Optical Systems ◽  
Two Dimensional

scholarly journals Application of two-dimensional fast Fourier transform algorithm, analog of the Cooley-Tukey algorithm, for 4k fixed format digital image of satellite data in frequency domain processing

2020 ◽  
Vol 149 ◽  
pp. 02010 ◽  
Author(s):  
Mikhail Noskov ◽  
Valeriy Tutatchikov
Keyword(s):  
Fourier Transform ◽  
Numerical Experiment ◽  
Fast Fourier Transform ◽  
Frequency Domain ◽  
Discrete Fourier Transform ◽  
Satellite Data ◽  
Digital Image ◽  
Digital Images ◽  
Two Dimensional ◽  
Fast Fourier Transform Algorithm

Currently, digital images in the format Full HD (1920 * 1080 pixels) and 4K (4096 * 3072) are widespread. This article will consider the option of processing a similar image in the frequency domain. As an example, take a snapshot of the earth's surface. The discrete Fourier transform will be computed using a two-dimensional analogue of the Cooley-Tukey algorithm and in a standard way by rows and columns. Let us compare the required number of operations and the results of a numerical experiment. Consider the examples of image filtering.

Computer aided measurement of biomechanical characteristics of cadaverous lumbar spines

Open Physics ◽  
2004 ◽  
Vol 2 (3) ◽  
Author(s):  
Luděk Bartoněk ◽  
Jiří Keprt ◽  
Jiří Charamza ◽  
Lumír Hrabálek
Keyword(s):  
Fourier Transform ◽  
Fast Fourier Transform ◽  
Laser Light ◽  
Ccd Camera ◽  
Optical Signal ◽  
Two Dimensional ◽  
Fast Fourier Transform Algorithm ◽  
Interference Fringes ◽  
Computer Aided

AbstractSpecial computer-aided equipment was designed for measurement of biomechanical characteristics of lower part of the spine (L1-L5). When the stress is applied, it is necessary to observe the shift of the sample elements, together with measurement of the spine rigidity. This shift is determined with the help of circular targets fitted to the appropriate vertebra. The targets, illuminated by lamp or laser light, are monitored and their digitalized images are scanned by CCD camera is stored as computer media. The two dimensional Fourier transform of the digital optical signal is obtained by the fast Fourier transform algorithm. The period and direction of the interference fringes determine the size and the direction of the sample shift.

Fast Fourier Transform Based Numerical Methods for Elasto-Plastic Contacts of Nominally Flat Surfaces

2008 ◽  
Vol 75 (1) ◽  
Author(s):  
W. Wayne Chen ◽  
Shuangbiao Liu ◽  
Q. Jane Wang
Keyword(s):  
Fourier Transform ◽  
Numerical Methods ◽  
Fast Fourier Transform ◽  
Analytical Solutions ◽  
Three Dimensional ◽  
Stress And Strain ◽  
Two Dimensional ◽  
Response Functions ◽  
Strain Fields ◽  
Flat Surfaces

This paper presents a three-dimensional numerical elasto-plastic model for the contact of nominally flat surfaces based on the periodic expandability of surface topography. This model is built on two algorithms: the continuous convolution and Fourier transform (CC-FT) and discrete convolution and fast Fourier transform (DC-FFT), modified with duplicated padding. This model considers the effect of asperity interactions and gives a detailed description of subsurface stress and strain fields caused by the contact of elasto-plastic solids with rough surfaces. Formulas of the frequency response functions (FRF) for elastic/plastic stresses and residual displacement are given in this paper. The model is verified by comparing the numerical results to several analytical solutions. The model is utilized to simulate the contacts involving a two-dimensional wavy surface and an engineering rough surface in order to examine its capability of evaluating the elasto-plastic contact behaviors of nominally flat surfaces.

scholarly journals Application of parallel version two-dimensional fast Fourier transform algorithm, analog of the Cooley-Tukey algorithm, for digital image processing of satellite data

2019 ◽  
Vol 75 ◽  
pp. 01012 ◽  
Author(s):  
Mikhail Noskov ◽  
Valeriy Tutatchikov ◽  
Mikhail Lapchik ◽  
Marina Ragulina ◽  
Tatiana Yamskikh
Keyword(s):  
Remote Sensing ◽  
Fourier Transform ◽  
Fast Fourier Transform ◽  
Satellite Images ◽  
Satellite Image ◽  
Digital Processing ◽  
Two Dimensional ◽  
Fast Fourier Transform Algorithm ◽  
Suburban Areas ◽  
Parallel Version

In modern systems of remote sensing two-dimensional fast Fourier transform (FFT) has been widely used for digital processing of satellite images and subsequent image filtering. This article provides a parallel version two-dimensional fast Fourier transform algorithm, analog of the Cooley-Tukey algorithm and its implementation for processing the satellite image of Krasnoyarsk and its suburban areas.

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