Re: Octave 4.0.3: normxcorr2 producing unexpected result

[supr8sung]

I think this worked thanks.....


Supreet Singh

On Wed, Apr 19, 2017 at 12:30 AM, Hartmut [via Octave] <
address@hidden> wrote:

> When you use t = [1 1 1] you will get only 0s as result. And this is also
> correct.
>
> Reason:The normalized cross correlation is also normalized to the standard
> deviation of s and t. So in places where s or t have a standard deviation
> of 0 (like t in your case, try std(t) ) you will get an undefined result.
> Matlab decided to return a 0 value is this case. For the definition of the
> normalized cross correlation as well as for this Matlab behavior, see [1].
>
> If you want so search for image templates that are fully flat (i.e. with a
> standard deviation zero) than you should probably be using something
> different, but not normxcorr2. You might want to try corrcoef (in future
> Octave version 4.4) for your 1-D example, your just use stdfilt or
> rangefilt on real 2D images.
>
>      Hartmut
>
>
> [1] Matlab help page of normxcorr2:
>      Defintion: https://de.mathworks.com/help/images/ref/normxcorr2.html#
> bvibmz_-5
>      Dealing with std=0: https://de.mathworks.com/help/
> images/ref/normxcorr2.html#bvh5vek-3
>
> ------------------------------
> If you reply to this email, your message will be added to the discussion
> below:
> http://octave.1599824.n4.nabble.com/Octave-4-0-3-normxcorr2-producing-
> unexpected-result-tp4681543p4682910.html
> To unsubscribe from Octave 4.0.3: normxcorr2 producing unexpected result, 
> click
> here
> <http://octave.1599824.n4.nabble.com/template/NamlServlet.jtp?macro=unsubscribe_by_code&node=4681543&code=c3VwcmVldHNpbmdoMTA2QGdtYWlsLmNvbXw0NjgxNTQzfC0xODMwNzAzMDc1>
> .
> NAML
> <http://octave.1599824.n4.nabble.com/template/NamlServlet.jtp?macro=macro_viewer&id=instant_html%21nabble%3Aemail.naml&base=nabble.naml.namespaces.BasicNamespace-nabble.view.web.template.NabbleNamespace-nabble.view.web.template.NodeNamespace&breadcrumbs=notify_subscribers%21nabble%3Aemail.naml-instant_emails%21nabble%3Aemail.naml-send_instant_email%21nabble%3Aemail.naml>
>




--
View this message in context: 
http://octave.1599824.n4.nabble.com/Octave-4-0-3-normxcorr2-producing-unexpected-result-tp4681543p4682914.html
Sent from the Octave - General mailing list archive at Nabble.com.