Linked Questions

0
votes
3answers
2k views

What is the basic concept of Fourier transform

I use discrete Fourier transform for digital image processing purposes , but I don't understand basic concept behind it. For example : What information exists in frequency domain? What is ...
10
votes
2answers
217 views

On the de-noising of time-frequency images

I am wondering what techniques might be available for 'de-noising' the following example time-frequency image that was created using Welch's method. The following plot was created from a robotic ...
4
votes
2answers
4k views

Why Frequency Domain conversion is Important in Digital Image Processing?

Any Image enhancement technique can be easily applied to the normal images. Still, most of the folks say that frequency domain conversion of the images can lead to better enhancement. Why do we need ...
3
votes
2answers
2k views

Comparing Image FFT with Sine wave FFT

So, When we take the FFT of any Composite or Single Sine Wave we get exact frequency on x-axis of the plot. The point where we get the original frequency in FFT is depend upon the Sampling Rate and ...
2
votes
2answers
446 views

Fourier Decomposition

Hello everyone have a look at this video of Fourier Decomposition of an image(otherwise you can also refer the image which shows few plots of different extracted waves from an image) . We also know ...
1
vote
2answers
981 views

Finding the Harmonics contained in an Image?

I am beginer in image processing. Any signal whether it is 1D,2D or any multidimensional signal can be represented using combination of number of sine and cosine wavesforms (harmonics). Similerly any ...
1
vote
2answers
291 views

How does Fourier Transform manipulates image technically?

I need a little bit more explanation on technical details regarding Fourier Transform in Image Processing, mainly on the frequency aspect. I see that we can use Discrete Fourier Transform to change ...
0
votes
2answers
73 views

I'm confused about the notion of frequency when it comes to arbitrary data

In signal processing class we keep learning about how it's so useful to bring things into the frequency domain instead of the time or space domain but I'm very confused about what the motivation is or ...
0
votes
2answers
115 views

Filtering + Images [duplicate]

Possible Duplicate: What does frequency domain denote in case of images? I am studying applications of low and high pass filters in images. However, first I'm trying to understand what exactly ...
4
votes
1answer
490 views

Is it possible to decompose an image into basis images using MATLAB?

I have read that: Using Fourier decomposition any arbitrary image can be represented as summation of orthogonal basis images. I want to see the basis images for any image say Lena or Cameraman, ...
4
votes
1answer
2k views

Which information do we get from magnitude and phase spectrum?

I am learning image processing. I want to ask very basic question related to FFT topic Which information do we actually get from "phase spectrum" and "magnitude spectrum" about an image?
3
votes
1answer
450 views

What is the role of Freqency in Digital Images [duplicate]

Possible Duplicate: What does frequency domain denote in case of images? If we look deeply into Digital Images they are purely generated by the pixels distributed in rows and coloumn and the ...
1
vote
1answer
661 views

Frequency Spectrum of an image

I have been studying about Frequency Domain from many days but still i am not able to clear one of the confusion. We say that in frequency domain an image is represented as waves. What I am able to ...
1
vote
1answer
230 views

Can you explain how to imagine frequency in 2D? I need to understand how the concept of frequency exists in images [duplicate]

The concept of frequency spectrum exists because it is possible to sum sines and cosines of various frequencies together to make any periodic signal. The frequencies of these individual sinusoids make ...
0
votes
1answer
3k views

Compare phase and magnitude spectrum results of 2 Images [duplicate]

I have read that from Fourier transform we obtain magnitude and phase spectrum. The magnitude spectrum tells you how strong are the harmonics in a image and the phase spectrum tells where this ...

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