250 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 ...
639 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, ...
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?
2k views

### Understanding FFT of an Image

I am having trouble identifying the frequency components of an image, Here I simply generated, 256x256 binary-image. a = [zeros(256,128) ones(256,128)]; imshow(a); ...
7k 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 ...
470 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 ...
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 ...
663 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 ...
563 views

### Importance of Phase in FFT of an image

While processing digital images in the Fourier domain, mostly we exploit the amplitude and not the phase. This could be because the amplitude is much more structured and the amplitude spectrum reveals ...
21k views

### Frequency spectrum of a set of images in Matlab

I wish the compute the frequency distribution of a set of images. I basically am keen on finding out how the the frequency varies in the images. I know I can use the 'fft2' function to compute the 2-...
342 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 ...
1k 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 ...
1k 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 ...