Re: Accurate edge detection?

> > probably true, but doesn't this still simply assert that the maximum
> > slope/gradient of the real physical edge image corresponds to the true
> > edge location?
>
> It is not an assertion; it is a proof, under certain assumptions.

Not true. Simple samples like Fraunghofer's diffraction, have no such
a property. True edge location is a thing, what has a meaning only for
some sort of images. But, if you have a grayscale image, you may have
no such things as an edge at all. Unfocused photo, for example. But,
even for two color images, where edge position has of course sence,
its proper location depends on the whole image. Interferention and
diffraction, nothing to do. Therefore, it is not a local problem. The
only way to solve it is using knowledge of how the source inage is
transformed (this info may be calculated or measured, using some test
images with known structure) and which this sorce image could be
(smooth edges, for example, not a random set of colored dots), to find
such a source, what after transform looks like scanned image what one
has. To start with some rough approximation and, step by step,
iteration by iteration, morph it, trying to get something similar to
scanned one.