| Re: Thinning image morphological operator [message #49160] |
Thu, 29 June 2006 23:45  |
Karsten Rodenacker
Messages: 98
Registered: July 1997
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Member |
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Ja, you are right. The idl implementation THIN seems to result from times
where connectivity was an unfamiliar term. The routine is comparingly
quick but not connectivity preserving. Maybe a closing (MORPH_CLOSE) might
help in some cases.
Unluckily the implementation of EROSION and DILATION is likewise not just
satisfying. I had a long fruitless discussion about that with RSI. At
least they add some more documentation concerning the unusual border
behaviour. Possibly critical remarks might help to convince VTT that there
is some necessity to train somebody in mathematical morphology. In terms
of math. morph and connectivity my reference is a very old program from
Ecole de Mines, Fontainebleau, France, microMORPH, unluckily not freeware,
where connectivity and border behaviour are implemented consistently.
Regards
Karsten
Am Fri, 30 Jun 2006 00:15:04 +0200 schrieb Tom S. <twslankard@gmail.com>:
> I had a question about the THIN function in IDL. I was under the
> impression that this operation was supposed to preserve connectivity.
> Am I mistaken? The IDL implementation does not seem to do so.
>
> The image linked below is output from a program I wrote. It simply
> takes the image on the left and applies the THIN function, yielding the
> image on the right. (Note the gap that forms toward the bottom.)
>
> http://twslankard.googlepages.com/fluke.jpg
>
> Is this a problem with my understanding of the thinning operation or is
> it a problem with the THIN function? Any assistance is greatly
> appreciated!
>
> Regards,
> Tom S.
>
--
Erstellt mit Operas revolutionï¿œrem E-Mail-Modul: http://www.opera.com/m2/
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| Re: Thinning image morphological operator [message #49233 is a reply to message #49160] |
Wed, 05 July 2006 07:21  |
Ulan
Messages: 8
Registered: April 2005
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Junior Member |
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Yeah, I 've also noticed connectivity loss with THIN. I used Laplacian
filter prior to thinning to insure the THIN doesn't remove thinner
parts ...
Regards,
Ulan
Karsten Rodenacker wrote:
> Ja, you are right. The idl implementation THIN seems to result from times
> where connectivity was an unfamiliar term. The routine is comparingly
> quick but not connectivity preserving. Maybe a closing (MORPH_CLOSE) might
> help in some cases.
>
> Unluckily the implementation of EROSION and DILATION is likewise not just
> satisfying. I had a long fruitless discussion about that with RSI. At
> least they add some more documentation concerning the unusual border
> behaviour. Possibly critical remarks might help to convince VTT that there
> is some necessity to train somebody in mathematical morphology. In terms
> of math. morph and connectivity my reference is a very old program from
> Ecole de Mines, Fontainebleau, France, microMORPH, unluckily not freeware,
> where connectivity and border behaviour are implemented consistently.
>
> Regards
> Karsten
>
> Am Fri, 30 Jun 2006 00:15:04 +0200 schrieb Tom S. <twslankard@gmail.com>:
>
>> I had a question about the THIN function in IDL. I was under the
>> impression that this operation was supposed to preserve connectivity.
>> Am I mistaken? The IDL implementation does not seem to do so.
>>
>> The image linked below is output from a program I wrote. It simply
>> takes the image on the left and applies the THIN function, yielding the
>> image on the right. (Note the gap that forms toward the bottom.)
>>
>> http://twslankard.googlepages.com/fluke.jpg
>>
>> Is this a problem with my understanding of the thinning operation or is
>> it a problem with the THIN function? Any assistance is greatly
>> appreciated!
>>
>> Regards,
>> Tom S.
>>
>
>
>
> --
> Erstellt mit Operas revolutionärem E-Mail-Modul: http://www.opera.com/m2/
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