How to compute power spectrum from 2D FFT

Posted by user1452954 on Stack Overflow See other posts from Stack Overflow or by user1452954
Published on 2013-11-08T19:42:01Z Indexed on 2013/11/08 21:53 UTC
Read the original article Hit count: 172

Filed under:

matlab

|

fft

I've encounter a problem when doing my lab assignment, not sure how to implement this:

Use fft2 on a gray image and to do Fourier transform and then compute the power spectrum. This is my code so far:

>> Pc = imread('pckint.jpg');
>> whos Pc;
  Name        Size             Bytes  Class    Attributes

  Pc        256x256            65536  uint8              

>> imshow(Pc);
>> result = fft2(Pc);

My question is from the result. How to computer power spectrum?

© Stack Overflow or respective owner

Related posts about matlab

Importing matlab functions in matlab

as seen on Stack Overflow - Search for 'Stack Overflow'
Hi, I have some Matlab functions defined in .m files and I'd like to import them into Matlab (as in I'd like them to form part of the commands). Is this possible please and how can I do this? Thank you very much and regards, Krt_Malta >>> More
c# with matlab dll should be running on pc without matlab

as seen on Stack Overflow - Search for 'Stack Overflow'
hi, i have a very big problem. ich wrote a programm which is using a matlab dll. i build some classes with the matlab .net builder. it runs on my pc :) the problem is, i want to use ist on a pc without matlab. so i installed mcr, but it dont run :( what are the steps i should do? the system variable… >>> More
Matlab and .NET Interaction

as seen on Stack Overflow - Search for 'Stack Overflow'
Hi All! I'm having an issue interacting between Matlab and .NET. I've managed to call .NET methods from Matlab code and vice versa. However, if I call a .NET method that, in turn, instantiates a Matlab object, it crashes (with a type initialization exception). Think about this scenario: a .NET… >>> More
Matlab matrix replacement assignment gives error

as seen on Stack Overflow - Search for 'Stack Overflow'
Hello, when i tried to update some part of a matrix, i got the following error message: ??? Assignment has fewer non-singleton rhs dimensions than non-singleton subscripts My code tries to update some values of a matrix that represent a binary image. My code is as follows: outImage(3:5,2:4,1) =… >>> More
MATLAB matrix replacement assignment gives error

as seen on Stack Overflow - Search for 'Stack Overflow'
I tried to update some part of a matrix, I got the following error message: ??? Assignment has fewer non-singleton rhs dimensions than non-singleton subscripts My code tries to update some values of a matrix that represent a binary image. My code is as follows: outImage(3:5,2:4,1) = max(imBinary(3:5… >>> More

Related posts about fft

Do you know a good and efficient FFT?

as seen on Stack Overflow - Search for 'Stack Overflow'
Hi, I am trying to find a very fast and efficient Fourier transform (FFT). Does anyone know of any good ones. I need to run it on the iPhone so it must not be intensive. Instead, maybe you know of one that is wavelet like, i need frequency resolution but only a narrow band (vocal audio range up… >>> More
fft understanding

as seen on Stack Overflow - Search for 'Stack Overflow'
Can somebody give a good explanation of FFT image transform How the FFT transformed image and it's Re^2+Im^2 image can be analyzed? I just want to understand something when loiking to the image and it's frequency. >>> More
c++ FFT Beat detection library?

as seen on Stack Overflow - Search for 'Stack Overflow'
Hi, I am currently looking around for a good allround beat detection library / source code in C++ since I found it really hard to achieve satisfying results with the beat detection code I wrote myself using this tutorial: http://www.gamedev.net/reference/programming/features/beatdetection/ It's… >>> More
Normalize FFT magnitude to imitate WMP

as seen on Stack Overflow - Search for 'Stack Overflow'
So, I've been working on a little visualizer for sound files, just for fun. I basically wanted to imitate the "Scope" and "Ocean Mist" visualizers in Windows Media Player. Scope was easy enough, but I'm having problems with Ocean Mist. I'm pretty sure that it is some kind of frequency spectrum, but… >>> More
VB FFT - stuck understanding relationship of results to frequency

as seen on Stack Overflow - Search for 'Stack Overflow'
Trying to understand an fft (Fast Fourier Transform) routine I'm using (stealing)(recycling) Input is an array of 512 data points which are a sample waveform. Test data is generated into this array. fft transforms this array into frequency domain. Trying to understand relationship between freq,… >>> More