Re: Math > Log Problem?

Posted by Wayne Rasband on Feb 20, 2006; 2:46am
URL: http://imagej.273.s1.nabble.com/Math-Log-Problem-tp3703653p3703654.html

> I tried to use the Process > Math > Log functions on the
> sample image "TEM_filter_sample.gif" in both ImageJ and
> Scion Image but the result is different!
> What could be the problem? The image in ImageJ seems to
> be much lighter after the processing than it looks in Scion
> Image where it is darker. How can the same procedure give
> different results in different softwares?

NIH Image and Scion Image display display 0 pixels as white and 255  
pixels as black. You can get ImageJ to behave the same way by  
inverting the image (Edit>Invert) and using an inverting lookup table  
(Image>Lookup Tables>Invert LUT). Or use the Process>Math>Exp command  
added in ImageJ 1.35q.

-wayne