<DIV>Hi Jakub, </DIV>
<DIV> </DIV>
<DIV>I took a look on your filter. However, I think there was a misunderstanding. </DIV>
<DIV> </DIV>
<DIV>I don't want to perform a pixel-wise log operation on my image. </DIV>
<DIV> </DIV>
<DIV>Actually, I want to perform a kind of histogram transform called <STRONG>histogram logarithmic</STRONG> to improve the contrast of my image. </DIV>
<DIV> </DIV>
<DIV>So far, I performed histogram usual rescaling to transform my intensities into the interval 0-255. Now, I would like my distribution of gray intensities would be adjusted to improve contrast like:</DIV>
<DIV> </DIV>
<DIV>f`'(x,y) = f min * (fmax / fmin) * P(f(x,y)) where P is the cumulated histogram.</DIV>
<DIV> </DIV>
<DIV>So adaptor will not help me, because this is an overall transform of the image. Maybe I have to create my own filter but how can I access the matrice of my pixel data form my image? </DIV>
<DIV> </DIV>
<DIV>thanks,</DIV>
<DIV> </DIV>
<DIV>Isabelle</DIV>
<DIV><BR><BR><B><I>Jakub Bican <jakub.bican@matfyz.cz></I></B> a écrit :</DIV>
<BLOCKQUOTE class=replbq style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #1010ff 2px solid"><BR>Hi Isabelle,<BR><BR>logarithmic scaling can be done by these filters:<BR><BR>LogImageFilter ( <BR>http://www.itk.org/Doxygen/html/classitk_1_1LogImageFilter.html )<BR>Log10ImageFilter ( <BR>http://www.itk.org/Doxygen/html/classitk_1_1Log10ImageFilter.html )<BR><BR>and/or adaptors:<BR><BR>LogImageAdaptor ( <BR>http://www.itk.org/Doxygen/html/classitk_1_1LogImageAdaptor.html )<BR>Log10ImageAdaptor ( <BR>http://www.itk.org/Doxygen/html/classitk_1_1Log10ImageAdaptor.html )<BR><BR>Hope this will help you.<BR><BR>Regards,<BR>Jakub<BR><BR><BR>Renaud Isabelle napsal(a):<BR><BR>> Hi Luis,<BR>> <BR>> In one of your numerous posted replies, you already mentioned the use <BR>> of *logarithmic scaling* to improve visualisation of images.<BR>> <BR>> "It is not rare to use a logarithmic intensity transformation in order <BR>> to display the FFT output and still be able to
"see" something."<BR>> http://public.kitware.com/pipermail/insight-users/2004-November/011201.html<BR>> <BR>> This is actually what I need to do to improve the quality of my <BR>> ultrasonographic image.<BR>> <BR>> --> Could you tell me a way to perform this logarithmic scaling? Is <BR>> there already a function for that, or maybe could I compute my own one <BR>> if you tell me how to get access of the pixel data of my image <BR>> displayed with ITK and VTK.<BR>> <BR>> Thanks for answer,<BR>> <BR>> Isabelle<BR>><BR>> ------------------------------------------------------------------------<BR>> *Appel audio GRATUIT partout dans le monde* avec le nouveau Yahoo! <BR>> Messenger<BR>> Téléchargez le ici ! <BR>> <HTTP: fr.messenger.yahoo.com *http: default mail_taglines messenger
us.rd.yahoo.com><BR>><BR>><BR>>------------------------------------------------------------------------<BR>><BR>>_______________________________________________<BR>>Insight-users mailing list<BR>>Insight-users@itk.org<BR>>http://www.itk.org/mailman/listinfo/insight-users<BR>> <BR>><BR>_______________________________________________<BR>Insight-users mailing list<BR>Insight-users@itk.org<BR>http://www.itk.org/mailman/listinfo/insight-users<BR></BLOCKQUOTE><p>
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