Steve on Image Processing with MATLAB

Image processing concepts, algorithms, and MATLAB


Steve on Image Processing with MATLAB has been archived and will not be updated.

Posts 1 - 10 of 22

Results for: Fourier transforms

FFT Spectral Leakage 10

A MATLAB user recently contacted MathWorks tech support to ask why the output of fft did not meet their expectations, and tech support asked the MATLAB Math Team for assistance. Fellow Georgia Tech... read more >>

Fourier series animation using phasor addition 9

I just saw a great animation illustrating the Fourier series decomposition of a square wave. Check it out. The video includes two different animations, so be sure to watch it all the way through to... read more >>

Sinusoids and FFT frequency bins 13

ContentsConstruct the signalExploring the "spread" around the peakMoving the sinusoid frequency to line up with a binUsing a longer signalSummaryNote: I really didn't expect to be writing about the... read more >>

FFT Stories

My last meeting of the day ended just a little while ago, and I was starting to think seriously about figuring out a blog post for this week. What to write about? That's when I happened to see that Cleve posted just yesterday about the FFT. Ah ha! I'll write about that, too (in honor of National Blog About the FFT Week).... read more >>

Fourier transforms, vertical lines, and horizontal lines 14

A reader asked in a blog comment recently why a vertical line (or edge) shows up in the Fourier transform of an image as a horizontal line. I thought I would try to explain this using the... read more >>

Complex surprises from fft 9

One of the discrete-time Fourier transform properties that many people learn is that if a sequence is conjugate symmetric, , then the Fourier transform is real. Therefore it... read more >>

Plotting the DTFT using the output of fft 6

In my Fourier transform series I've been trying to address some of the common points of confusion surrounding this topic. For today's espisode I want to look at how to use the fft... read more >>

Negative frequencies 10

I recently asked for your advice about how to continue my Fourier transform series. I appreciate all the enthusiastic and helpful responses. I'd like to continue focusing on some basic points... read more >>

Fourier transforms – where to go from here 26

Last fall I started posting occasionally about Fourier transforms. This topic causes much confusion, which is particularly unfortunate given how many people are interested in it. I... read more >>

No units in the DTFT 4

OysterEngineer (I love that name!) asked some interesting questions in response to my last Fourier transform post, which concerned the relationship between the discrete-time Fourier transform... read more >>

Posts 1 - 10 of 22