How to design for Fourier filters?

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Discussion Overview

The discussion revolves around the design of Fourier filters for optical image processing, specifically focusing on high pass filtering techniques for edge enhancement. Participants explore methods for determining filter dimensions and characterizing spatial frequencies within the context of Fourier optics.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant seeks assistance on how to design high pass filters for edge enhancement in Fourier optics.
  • Another participant suggests converting images to the Fourier domain, removing low-frequency components, and then applying the inverse Fourier transform, noting that filter design is a complex topic.
  • A participant expresses difficulty in calculating the dimensions of the high pass filter and characterizing spatial frequencies, stating that existing literature does not provide adequate methods for their specific needs.
  • One suggestion is made to seek further assistance from the comp.dsp USENET newsgroup for additional insights.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the methods for designing filters, and multiple competing views regarding the approach to high pass filtering remain evident.

Contextual Notes

Limitations in the discussion include a lack of specific methodologies for filter design and characterization of spatial frequencies, as well as potential dependencies on definitions that are not fully explored.

jaycee4u
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I am working on an experiment on Fourier optics-optical image processing. In order to get edge enhancement, how do we actually go about high pass filtering. How to design filters? How to decide the filter dimensions? Can anyone please help me?
 
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Convert the image to the Fourier domain, lop off the low-frequency components you don't want, then take the inverse Fourier transform to get back an image. The design of filters is an immense topic, much too large to describe here.

- Warren
 
I have done that. But to get edge enhancement, hoe to calculate the dimensions of the high pass filter? How to characterize the spatial frequencies? I went through a few books but none gave a method to design filters for my purpose. Would you help me?
 
jaycee4u said:
I have done that. But to get edge enhancement, hoe to calculate the dimensions of the high pass filter? How to characterize the spatial frequencies? I went through a few books but none gave a method to design filters for my purpose. Would you help me?

i would take this question to the comp.dsp USENET newsgroup. Google Groups is one way to post there.
 

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