Re: Possible bug with perimeter calculation on composite selections

Posted by Chris Bradhurst on Jan 27, 2009; 4:28am
URL: http://imagej.273.s1.nabble.com/Possible-bug-with-perimeter-calculation-on-composite-selections-tp3693924p3693925.html

On Mon, 26 Jan 2009 12:31:48 -0600, Kenneth Sloan <[hidden email]>
wrote:

>It's worth noting that "perimeter" is a notoriously difficult concept
>to nail down.
>The answer depends on scale, and on what you think a "pixel" is, and
>on precisely
>where you think the boundary is.
>
>In my opinion, "perimeter" is nearly useless when used across
>different studies
>done by different observers.

For my application, I would like to compare the average perimeter per object
in one class of images versus the average perimeter per object in another
class.  The actual real-world value of measurement is not important in this
case.  So provided the method of perimeter calculation works consistently, I
think it should be fine.

As far as whether perimeter will actually have any discriminating value
remains to be seen, although I suspect it will likely be ineffective, in
accord with your experience.