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Re: Modifying Image Histograms

Posted by Noel BONNET on Jun 28, 2007; 8:12am
URL: http://imagej.273.s1.nabble.com/Modifying-Image-Histograms-tp3698976p3698977.html

Hello,

Could I suggest another way to "solve" (???) the problem. Instead of
modifying the histogram (in fact, the image) in order to be able to use
always the same threshold, it is sometimes more appealing to avoid
thresholding...
This is basically the philosophy of our approach published in (Bonnet N.,
Cutrona J. and Herbin M. "No-threshold" histogram-based image segmentation.
Pattern Recognition 2002, 35, 2319-2322).
A plugin for ImageJ (called Segmentation_fuzzy_514) is available at:
http://www.univ-reims.fr/INSERM514/ImageJ
A more extended description of the method is also available.

Since no threshold has to be defined, the approach is (in principle!) able
to work on series of images without modifying anything.

I hope it helps.

Noel Bonnet




On Thu, 21 Jun 2007 10:27:37 -0500, Rotella, Anthony M. (GRC)[]
<[hidden email]> wrote:

>Hello,
>
> I need to threshold a large number of images that are similar,
>but not quite the same. The vast majority threshold satisfactorily
>within the same range, but some are far enough off to throw the
>calculations and the accuracy out the window. Basically, I was wondering
>if there is a way to change the images so that the important features of
>the histograms of the slices in the stack fit into the same range, but
>so that the pixels still maintain their relative values between each
>other, so the same features of the image still threshold out correctly.
>Unfortunately the Autothreshold is way off. I tried Enhance Contrast,
>but makes the images very messy and doesn't work well. Another fix to my
>problem is if someone knows how to increase the difference in pixel
>intensities between objects in the foreground and background. I can
>clearly see the difference , but of course, ImageJ can't just do what I
>want, and some of the objects that I want to have thresholded out have
>the same intensities as something in the background, maybe somewhere
>else in the image. Unfortunately, I am hesitant to post the images on a
>hosting service, but I can e-mail them to anyone that wants to see them.
>Thanks, and sorry for the vague question!
>
>Tony Rotella
>========================================================================