Difference between focus and out of focus images.

Hello everyone.

I have a stack of images and I am trying to find which of those are in focus and which of those are out of focus?

How can I do this?

thanks

Answer 1

[Image Analyst]

You can use contrast detection. See http://en.wikipedia.org/wiki/Autofocus

Or you can take the FFT and sum up the higher frequencies.

Or you can call stdfilt() or imgradient() and take the mean of the output image, the thought being that the in focus image will have more edges and thus the mean will be higher.