'Fourier transform' diaporamas de présentation

Fourier Transform J.B. Fourier 1768-1830

Fourier Transform J.B. Fourier 1768-1830. Image Enhancement in the Frequency Domain 1-D. A. A. sin(x). 3 sin(x). B. + 1 sin(3x). A+B. + 0.8 sin(5x). C. A+B+C. + 0.4 sin(7x). D. A+B+C+D. A sum of sines and cosines. =. Fourier spectrum of step function.

2.3k views • 114 slides

38655 BMED-2300-02 Lecture 13: CT Reconstruction Ge Wang, PhD Biomedical Imaging Center

38655 BMED-2300-02 Lecture 13: CT Reconstruction Ge Wang, PhD Biomedical Imaging Center CBIS/BME , RPI wangg6@rpi.edu March 6, 2018. Are Your Scores Good?. BB Schedule for S18. Office Hour: Ge Tue & Fri 3-4 @ CBIS 3209 | wangg6@rpi.edu

916 views • 53 slides

MRI Image Formation

MRI Image Formation. Karla Miller FMRIB Physics Group. Image Formation. Gradients and spatial encoding Sampling k -space Trajectories and acquisition strategies Fast imaging Acquiring multiple slices Image reconstruction and artifacts. field strength. field offset.

4.16k views • 53 slides

ENG4BF3 Medical Image Processing

ENG4BF3 Medical Image Processing. Wavelet and Multiresolution Processing. Introduction. Unlike Fourier transform, whose basis functions are sinusoids, wavelet transforms are based on small waves, called wavelets, of limited duration.

1.04k views • 49 slides

An Overview of Fractional Order Signal Processing (FOSP) Techniques

An Overview of Fractional Order Signal Processing (FOSP) Techniques. YangQuan Chen*, Rongtao Sun+, Anhong Zhou#. *Center for Self-Organizing and Intelligent Systems (CSOIS), Department of Electrical & Computer Engineering, Utah State University +Phase Dynamics, Inc. Richardson,TX75081

1.04k views • 47 slides

Fractional fourier transform

Fractional fourier transform. Presenter: Hong Wen-Chih. Outline. Introduction Definition of fractional fourier transform Linear canonical transform Implementation of FRFT/LCT The Direct Computation DFT-like Method Chirp Convolution Method Discrete fractional fourier transform

1.26k views • 47 slides

EE 7730

EE 7730. 2D Fourier Transform. Summary of Lecture 2. We talked about the digital image properties, including spatial resolution and grayscale resolution. We reviewed linear systems and related concepts, including shift invariance, causality, convolution, etc. Fourier Transform.

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Image Processing Basics

Image Processing Basics. What are images?. An image is a 2-d rectilinear array of pixels. Pixels as samples. A pixel is a sample of a continuous function. Images are Ubiquitous. Input Optical photoreceptors Digital camera CCD array Rays in virtual camera (why?) Output TVs

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Outline

Outline. Transmitters (Chapters 3 and 4, Source Coding and Modulation) (week 1 and 2) Receivers (Chapter 5) (week 3 and 4) Received Signal Synchronization (Chapter 6) (week 5) Channel Capacity (Chapter 7) (week 6) Error Correction Codes (Chapter 8) (week 7 and 8)

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Chapter 2 Signals and Systems

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Unit 5

Unit 5. The Fourier Transform. Courtesy of Professor Alan M. Nathan, University of Illinois at Urbana-Champaign. Unit 5. Many, many different equations for Fourier Transforms . . . . . 1. Mathematician Approach 2. Engineering Approach Even within each approach there are many equations.

435 views • 30 slides

ERL & Coherent X-ray Applications

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Vibrational Wavefunctions

Vibrational Wavefunctions. Spectrometers - Prism. Diffraction. Gratings. Flash Photolysis. Signal-to-Noise. Fourier Transform. http://talklikeaphysicist.com/2008/must-see-fourier-transform-tattoo/. Microwave Spectrometers. Microwave Sources. Microwave Ovens. Spectrometers Compared.

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Symmetry and the DTFT

Symmetry and the DTFT. If we know a few things about the symmetry properties of the DTFT, it can make life simpler. First, for a real-valued sequence x(n), the amplitude spectrum (magnitude of the DTFT) is an EVEN function of w . To show this first show that,. Symmetry and the DTFT.

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Interstellar Levy Flights

Interstellar Levy Flights. Collaborators: Stas Boldyrev (U Chicago: Theory) Ramachandran (Berkeley: Pulsar Observing) Avinash Deshpande (Arecibo, Raman Inst: More Pulsars) Ben Stappers (Westerbork: Crucial pulsar person). Outline of Talk: Gambling with Pennies Statistics

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Theory of Reconstruction

Theory of Reconstruction. What are inside the gantry?. Schematic Representation o f the Scanning Geometry of a CT System. X-ray. 2 % attenuation change detectable in film. CT. 0.2 % change in attenuation coefficient. y. x. f(x,y). CT, like X-ray measure line integrals.

379 views • 18 slides

Fourier Transform

Fourier Transform. Analytic geometry gives a coordinate system for describing geometric objects. Fourier transform gives a coordinate system for functions. Decomposition of the image function. The image can be decomposed into a weighted sum of sinusoids and cosinuoids of different frequency.

391 views • 18 slides

Image Compression - JPEG

Image Compression - JPEG. Video Compression. MPEG Audio compression Lossy / perceptually lossless / lossless 3 layers Models based on speech generation (throat), or ear characterisitics Image compression JPEG based Images take much more memory than voice

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Lecture 11

Lecture 11. Fourier Transforms. Fourier Series in exponential form. Consider the Fourier series of the 2T periodic function: Due to the Euler formula It can be rewritten as With the decomposition coefficients calculated as:. (1). (2). Fourier transform.

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Matched Filters

4.07k views • 14 slides