Perimeter, Does anyone know exactly how perimeter works?

[TLowe]

The perimeter function in ImageJ appears to act on edge pixels, assigning pixels along the edge os a selection then either a +1 length or a sqrt(2) length. It generally follows the equation Y+Xsqrt(2); where Y and X are whole numbers. I've been trying to come up with a list of "rules" for this assignment, but unsuccessfully. I've also been unable to come up with source code that should reveal what rules are being used. Does anyone know exactly how perimeter works?

[Herbie-4]

Tom Lowe,

ImageJ is open source, i.e. you should be able to find the very code.
Actually I found it easily:

<http://imagej.nih.gov/ij/source/ij/plugin/filter/Analyzer.java>

On this page do a search for PERIMETER.

HTH

Herbie

:::::::::::::::::::::::::::::::
On 26.10.14 17:38, TLowe wrote:

> The perimeter function in ImageJ appears to act on edge pixels, assigning
> pixels along the edge os a selection then either a +1 length or a sqrt(2)
> length. It generally follows the equation Y+Xsqrt(2); where Y and X are
> whole numbers. I've been trying to come up with a list of "rules" for this
> assignment, but unsuccessfully. I've also been unable to come up with source
> code that should reveal what rules are being used. Does anyone know exactly
> how perimeter works?
>
>
>
> -----
> Tom Lowe
> Chemical Technician
> Eastman Kodak
> --
> View this message in context: http://imagej.1557.x6.nabble.com/Perimeter-Does-anyone-know-exactly-how-perimeter-works-tp5010191.html
> Sent from the ImageJ mailing list archive at Nabble.com.
>
> --
> ImageJ mailing list: http://imagej.nih.gov/ij/list.html
>

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ImageJ mailing list: http://imagej.nih.gov/ij/list.html

[Mark Hiner]

Hi everyone,

>ImageJ is open source, i.e. you should be able to find the very code.
Actually I found it easily:

For reference, see also this FAQ entry
<http://imagej.net/FAQ#How_do_I_find_more_information_about_Command_X.3F>
for general steps on finding more information about a given command. Please
let me know if you try to use these instructions and have any problems.

Best,
Mark

On Sun, Oct 26, 2014 at 2:48 PM, Herbie <[hidden email]> wrote:

> Tom Lowe,
>
> ImageJ is open source, i.e. you should be able to find the very code.
> Actually I found it easily:
>
> <http://imagej.nih.gov/ij/source/ij/plugin/filter/Analyzer.java>
>
> On this page do a search for PERIMETER.
>
> HTH
>
> Herbie
>
> :::::::::::::::::::::::::::::::
>
> On 26.10.14 17:38, TLowe wrote:
>
>> The perimeter function in ImageJ appears to act on edge pixels, assigning
>> pixels along the edge os a selection then either a +1 length or a sqrt(2)
>> length. It generally follows the equation Y+Xsqrt(2); where Y and X are
>> whole numbers. I've been trying to come up with a list of "rules" for this
>> assignment, but unsuccessfully. I've also been unable to come up with
>> source
>> code that should reveal what rules are being used. Does anyone know
>> exactly
>> how perimeter works?
>>
>>
>>
>> -----
>> Tom Lowe
>> Chemical Technician
>> Eastman Kodak
>> --
>> View this message in context: http://imagej.1557.x6.nabble.
>> com/Perimeter-Does-anyone-know-exactly-how-perimeter-works-tp5010191.html
>> Sent from the ImageJ mailing list archive at Nabble.com.
>>
>> --
>> ImageJ mailing list: http://imagej.nih.gov/ij/list.html
>>
>>
> --
> ImageJ mailing list: http://imagej.nih.gov/ij/list.html
>

--
ImageJ mailing list: http://imagej.nih.gov/ij/list.html

[Adam Hughes]

You may want to read this older thread, where we got into a discussion on
various encoding algorithms.  I also found the perim. attribute to be
counter-intuitive in certain cases, and this clarified.

http://comments.gmane.org/gmane.comp.java.imagej/31695

On Mon, Oct 27, 2014 at 9:04 AM, Mark Hiner <[hidden email]> wrote:

> Hi everyone,
>
> >ImageJ is open source, i.e. you should be able to find the very code.
> Actually I found it easily:
>
> For reference, see also this FAQ entry
> <http://imagej.net/FAQ#How_do_I_find_more_information_about_Command_X.3F>
> for general steps on finding more information about a given command. Please
> let me know if you try to use these instructions and have any problems.
>
> Best,
> Mark
>
> On Sun, Oct 26, 2014 at 2:48 PM, Herbie <[hidden email]> wrote:
>
> > Tom Lowe,
> >
> > ImageJ is open source, i.e. you should be able to find the very code.
> > Actually I found it easily:
> >
> > <http://imagej.nih.gov/ij/source/ij/plugin/filter/Analyzer.java>
> >
> > On this page do a search for PERIMETER.
> >
> > HTH
> >
> > Herbie
> >
> > :::::::::::::::::::::::::::::::
> >
> > On 26.10.14 17:38, TLowe wrote:
> >
> >> The perimeter function in ImageJ appears to act on edge pixels,
> assigning
> >> pixels along the edge os a selection then either a +1 length or a
> sqrt(2)
> >> length. It generally follows the equation Y+Xsqrt(2); where Y and X are
> >> whole numbers. I've been trying to come up with a list of "rules" for
> this
> >> assignment, but unsuccessfully. I've also been unable to come up with
> >> source
> >> code that should reveal what rules are being used. Does anyone know
> >> exactly
> >> how perimeter works?
> >>
> >>
> >>
> >> -----
> >> Tom Lowe
> >> Chemical Technician
> >> Eastman Kodak
> >> --
> >> View this message in context: http://imagej.1557.x6.nabble.
> >>
> com/Perimeter-Does-anyone-know-exactly-how-perimeter-works-tp5010191.html
> >> Sent from the ImageJ mailing list archive at Nabble.com.
> >>
> >> --
> >> ImageJ mailing list: http://imagej.nih.gov/ij/list.html
> >>
> >>
> > --
> > ImageJ mailing list: http://imagej.nih.gov/ij/list.html
> >
>
> --
> ImageJ mailing list: http://imagej.nih.gov/ij/list.html
>

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