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Re: Modifying Image Histograms

Posted by Burger Wilhelm on Jun 22, 2007; 9:40am
URL: http://imagej.273.s1.nabble.com/Modifying-Image-Histograms-tp3698976p3698980.html

Hello,

histogram matching (or specification) IS available for ImageJ in the source code section of our book's support site at www.imagingbook.com . While the English edition is scheduled to appear in September, you could for now download the source code for the German edition from

   http://www.imagingbook.com/fileadmin/de/java2/ch05.zip

which contains English comments anyway. Hope this helps.

WB

--
Dr. Wilhelm BURGER
| upper austria univ. of applied sciences
| digital media
| A4232 Hagenberg, Austria
| www.fh-hagenberg.at/staff/burger
| www.imagingbook.com



> -----Original Message-----
> From: ImageJ Interest Group [mailto:[hidden email]] On
> Behalf Of Giancarlo Mascetti
> Sent: Thursday, June 21, 2007 7:01 PM
> To: [hidden email]
> Subject: Re: Modifying Image Histograms
>
> Hello Tony,
>          A method called "histogram matching" probably could
> solve your
> problem (the use the same threshold for a large number of "similar"
> images)... but unfortunately it is not yet available in
> ImageJ (or as a plugin)
> Some years ago I have written a matlab routine to perform
> such task but was
> very slow...
>
> Giancarlo
>
> At 10.27 21/06/07 -0500, you 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
>
> Giancarlo Mascetti, Ph.D.
> X-Istituto di Calcolo Scientifico
>
> c/o Paramed Health Services Ltd.
> c.so F. M. Perrone, 73r - 16152 Genova, Italy
> tel. 010-6489265 - mob. 335-7787927 - fax. 010-7404530
> E-mail: [hidden email]
>