How to find the PSF of an image?

Hi! I have a reconstructed image, I need to divide the image into four quadrants and find the PSF in each quadrant..Can somebody help me with a Code? Thanks in advance..

[Image Analyst]

Do you have what is known to be a point source, or a perfectly sharp edge in the image (not too hard)? Or is it just some general scene (try guessing)?

[ARUNKARTHIHEYAN THIYAGARAJAN]

I don't have an image of the point source..The image that I have is a Reconstructed image which doesn't have a sharp edge...

[Image Analyst]

Do you have the ground truth image? If not, then I think you can't do it. There could be lots of PSFs that could give that resulting image. For example a Gaussian with a sharp image, or a genuinely blurry image with a delta function for a PSF - they could both give the same image.

[ARUNKARTHIHEYAN THIYAGARAJAN]

I don't understand what you mean by a ground truth image. Please specify that. I have attached the picture that I am working on.

All I need to do is, divide the picture into four quadrants and find the psf of each quadrant.

[Image Analyst]

A ground truth image is an image of the true, known values. I'd say that you might be able to assume that the little lights are smaller than a pixel and therefore a point source as far as the image is concerned. So I'd crop out a blurry point source and call that the PSF.

[ARUNKARTHIHEYAN THIYAGARAJAN]

I am not able to understand...Could you please elaborate.. It would be very helpful if you can give me a code for calculating the psf of some random image..