Finding and using the Point Spread Function via FFT in Labview

In summary, my partners and I are trying to find the Point Spread Function (PSF) for a new microscope we are building, but we are having difficulty. There are some online resources that can help, but it requires some programming knowledge.
  • #1
Prodigalvanic
7
0
Hello!

My partners and I are building an NSOM microscope and it is mostly finished. Now we need to find the Point Spread Function.

My questions is how do I find the PSF in labview and how do I use it to deblur in labview?

What follows is some background on what I have attempted so far.

I built a VI and tested it with the image, object and PSF provided at the top of the wikipedia page (see below). It made FFTs of the image and object then divided the image FFT with the object FFT. In other words it deconvolved the image by the object. I figure the result should look like the PSF provided. It does not it is totally black.
Neither can I deconvolve the provided image by the provided PSF to get the provided object.

I am new to all of this. I understand another approach is to do a gaussian fit to a surface of the image. Then I can deconvolve that with the image. I cannot understand how to do this as the resources assume too much prior knowledge.

How do I deconvolve an FFT by a gaussian?! The websites discusses use of a "kernel" but I can find no explanation of what a kernel is. (I assume it has nothing to do with my operating system).


A webs resource I consulted
http://zeiss-campus.magnet.fsu.edu/articles/basics/psf.html

The source of my test images
http://en.wikipedia.org/wiki/Point_spread_function
 
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  • #2
If you know of a resource that explains this in lay terms please let me know. Thanks for your help!Unfortunately, deconvolution using Labview is not an easy task. The best way to approach this would be to use a mathematical approach, such as a gaussian fit. You can find some resources online that explain how to do this in Labview, although they might be a bit technical. It's also important to realize that the PSF is something that needs to be empirically determined for your particular system, so it's not something that can easily be calculated in Labview. You can also try using a library like scipy, which provides a deconvolution function. This can be used with Labview as well, but requires some basic knowledge of programming in python. If you are still having trouble, you could try reaching out to someone in your local area who has experience with this type of thing. There may be a professor or lab technician who could provide more specific advice on how to get started. Good luck!
 

Related to Finding and using the Point Spread Function via FFT in Labview

1. What is a Point Spread Function (PSF) and why is it important?

A Point Spread Function is a mathematical representation of how an imaging system or instrument blurs a point source of light. It is important because it provides information about the resolution and aberrations of the system, which is crucial for accurately interpreting and analyzing images.

2. How is the Point Spread Function determined using FFT in Labview?

The Point Spread Function can be determined using FFT (Fast Fourier Transform) in Labview by taking an image of a point source, such as a pinhole, and then analyzing the FFT of the image. The peak in the FFT corresponds to the PSF, which can then be used for further analysis.

3. Can the Point Spread Function vary for different imaging systems?

Yes, the Point Spread Function can vary for different imaging systems depending on factors such as the optics, sensor, and image processing algorithms. It is important to determine the PSF for each specific system in order to accurately interpret and analyze images.

4. Can the Point Spread Function be used to improve image quality?

Yes, the Point Spread Function can be used to improve image quality by providing information about the aberrations and limitations of the system. This information can be used to correct and compensate for these aberrations, resulting in sharper and more accurate images.

5. Are there any limitations to using FFT for determining the Point Spread Function?

While FFT is a powerful and commonly used method for determining the Point Spread Function, it may not be suitable for all imaging systems. In some cases, other methods such as deconvolution may be more appropriate. Additionally, the accuracy of the PSF determined by FFT can be affected by noise and other artifacts in the image.

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