Re: Accurate edge detection?

On Jul 22, 8:59=A0am, aruzinsky <aruzin...@[EMAIL PROTECTED]
> wrote:
> On Jul 22, 8:04=A0am, slus...@[EMAIL PROTECTED]
 wrote:
>
>
>
> > Thank you for your interest and offer to review some sample images.
> > Unfortunately, our concern is not on the software or algorithmic side,
> > but on the optical side. =A0As I mentioned in my original post:
>
> > "Does anyone have references they can point to (or their own
> > pesuasive
> > arguments) that describe where the true edge location should be
> > relative to the edge image function?"
>
> I already did. =A0What is wrong with you?
>
>
>
> > I also mentioned that I originally posted to sci.optics, then added
> > sci.image.processing because I thought the folks here might be more
> > aware of relavent references. =A0The (apparently) commonly held belief
> > that the maximum slope of the edge image, or the midpoint between the
> > maximum and minimum grey level values of the edge image corresponds to
> > the true edge location seems unmotivated or unsup****ted to me, even
> > though it "feels" like common sense. =A0
>
> That is an algorithm, albeit a really stupid one that is not common
> sense, so don't tell me that you are not interest in algorithms.
> Furthermore, that is not a commonly held belief, e.g., it is common
> knowledge that shock filters sharpen an edge around the inflection
> point (the inflection point is preserved) and nobody, I know of,
> pretends that shock filtering is deconvolution.
>
> > We have also performed bench
> > experiments that suggest that neither the max. slope nor the grey
> > level midpoint corresponds to the true edge, with errors being in the
> > range of 0.2 to 0.45 pixels in the experimental set up we used.
>
> I hope my tax money didn't fund that busy work.
>
> >=A0We
> > are continuing our own investigation, but I have to believe that
> > someone has already done this at some time and published their
> > results. =A0I'd love to find out that our own efforts at inventing the
> > wheel are unecessary. :-)
>
> I already gave you a reference to a relatively simple algorithm that
> might do better than 0.2 pixels. =A0 It would be foolish not to try it.

Aruzinsky,

This is a friendly advice: improve your attitude on the forum if you
want to gain more respect. Even a genius with a bad attitude is worse
than an ignorant person.
Then what you say will come across as more useful information, and you
will not be in a situation to repeat yourself to the original poster.
I am sure none of us here want to know where your tax money is spent,
this is not the place to discuss that. Please stick to the point. All
of us are here to learn and share.. not to boast, or vent off.

By the way, you did not reply to my response on references towards
optical effects that are actually non linear.

Stay cool, it will help you.

Peace!