[ImageJ-devel] Fwd: Hist thresh toolbox license question

Gabriel Landini G.Landini at bham.ac.uk
Mon Feb 18 16:39:23 CST 2013


On Monday 18 Feb 2013 21:13:42 Barry DeZonia wrote:
> I think Gabriel can shed light maybe on our change and if it was by design
> or not. (Gabriel its been present since 1.0). And I see your new version is
> >='s on both ends. So maybe this email is overkill. Any clarification on
> your thinking re: the 1.03 change would be appreciated.

Hi,
I am almost sure that the ">" was changed to ">=" because the algorithm might 
not find the threshold in the smoothed histogram if the values between the 
peaks are constant.

So it is possible to have a smoothed bimodal histogram in which the test 
y(k-1) > y(k) & y(k+1) > y(k)
is never passed.
Relaxing the ">" to ">=" finds a threshold which is the first value of the 
minimum in the smoothed histogram.

Cheers

Gabriel





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