Halo area of an object

How to calculate the halo area of an object out of focus?

thanks

Answer 1

[Image Analyst]

I think you mean the "Point Spread Function", which is the proper term, not halo area. You can measure this by taking the image of a point. Or you can also get it from an edge (the blurred profile of what should be a sharp edge) if you do some math involving the Fourier transform. Thresholding (your tag) does not really come into play.