How to estimate the modulation transfer function of images?
The &quot;classic&quot; way of estimating blurriness is (as far as I know) the difference of Gaussians approach: you filter your image with Gaussian blur filters of different variance. Then, you at which level of blurriness the most info is lost (i.e. where the largest difference between the last level of blurriness and the next level is).
If your image content is reliably high-frequency to begin with, a simple high pass filter followed by energy detection on regions (i.e. parts) of the image can be used to.
In the end, if you combine the idea of mapping linear operations (Gaussian blur, high pass filters) to spatially constrained regions, you end up with wavelets. This might be a very promising approach if you need to analyze properties of images later on (think, as a simple example, something like &quot;images which are sharp in about ¼ of the area&quot;, or &quot;images that contain both very blurred and very in-focus regions&quot; or so).