Posted by
Cammer, Michael on
Dec 05, 2016; 4:26pm
URL: http://imagej.273.s1.nabble.com/32-bit-to-8-bit-conversion-problem-tp5017682p5017687.html
Image > Adjust > Brightness/Contrast
Set (lower left button) the value you want to be zero and the value you want converted to 255.
Image > Type > 8-bit
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Michael Cammer, Microscopy Core & Skirball Institute, NYU Langone Medical Center
Cell: 914-309-3270 Office: Skirball 2nd Floor main office, back right
http://ocs.med.nyu.edu/microscopy &
http://microscopynotes.com/-----Original Message-----
From: ImageJ Interest Group [mailto:
[hidden email]] On Behalf Of Csaba DÁVID
Sent: Monday, December 05, 2016 3:13 AM
To:
[hidden email]
Subject: 32-bit to 8-bit conversion problem
Hello,I tried to convert images from 32-bit to 8 bit, which contain a lot of zero pixels, and a few pixels with different values. I checked up in the help and found: ImageJ converts 16-bit and 32-bit images to 8-bit by linearly scaling from min--max to 0--255
Therefore I set one pixel to the value 255, and thought it will result in an 8-bit image, where the original pixel values will be displayed (all of them are smaller than 255, of course).
But it did not happen. The original greates value was converted to 255 the others linearly scaled and the pixel which i set to 255 was also converted to 255. After hours of trial and error, i found that converting the image to results, and converting it back to image and then converting it to 8-bit gives the expected pixel values.
My questiona are:Why is it so? How can I solve the problem without this back and forth conversion?
all the bestsCsaba
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