Two dimensional discrete Fourier transform units

In summary, the units associated with each pixel in the frequency domain will be 1/length, with the specific unit depending on the units of the pixel width used in the transformation.
  • #1
LizardCobra
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Homework Statement


I have am doing a two dimensional discrete Fourier transform on an image (using MATLAB). What are the units associated with each pixel of the image in the frequency domain?



Homework Equations





The Attempt at a Solution


I thought that the frequency should be (+/-number of pixels away from the DC component)/(pixel width, in meters). This would give units of 1/length, which would make sense. Is this correct?
 
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  • #2


As a scientist who has experience with Fourier transforms, I can confirm that your understanding is correct. The units associated with each pixel in the frequency domain will be 1/length, as the Fourier transform represents the spatial frequency components of the image. The units will depend on the units of the pixel width used in the transformation. In the case of MATLAB, the default units are typically pixels, so the units in the frequency domain would be 1/pixel. However, if you have specified a different unit for the pixel width, such as meters, then the units in the frequency domain would be 1/meter. It is important to keep track of the units used in the transformation to ensure accurate interpretation of the results.
 

Related to Two dimensional discrete Fourier transform units

1. What is a two dimensional discrete Fourier transform (2D DFT) unit?

A 2D DFT unit is a mathematical algorithm used to convert a 2D signal from the spatial domain into the frequency domain. It decomposes the signal into its constituent frequencies, allowing for analysis and manipulation of the signal in the frequency domain.

2. How does a 2D DFT unit work?

A 2D DFT unit works by breaking down a 2D signal into its individual frequencies using a series of complex mathematical calculations. It then maps these frequencies onto a grid, known as a frequency domain grid, where the amplitude and phase of each frequency can be analyzed and manipulated.

3. What are the applications of 2D DFT units?

2D DFT units have a wide range of applications in fields such as signal processing, image and video processing, and pattern recognition. They are commonly used in image compression, noise reduction, and feature extraction.

4. Are there any limitations to using 2D DFT units?

One limitation of 2D DFT units is that they assume the signal is periodic, meaning that it repeats infinitely in both the x and y directions. This may not accurately represent real-world signals, leading to potential errors in the analysis and manipulation of the signal in the frequency domain.

5. How does a 2D DFT unit differ from a 1D DFT unit?

A 2D DFT unit operates on 2D signals, while a 1D DFT unit operates on 1D signals. This means that a 2D DFT unit takes into account both the horizontal and vertical frequencies of a signal, while a 1D DFT unit only considers the horizontal frequencies. Additionally, a 2D DFT unit produces a 2D frequency domain grid, while a 1D DFT unit produces a 1D frequency domain grid.

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