<div dir="ltr"><div class="markdown-here-wrapper" style="font-family:"Lucida Sans",Cantarell,Verdana,sans-serif;color:rgb(11,83,148)"><p style="margin:0px 0px 1.2em!important">Hi Ludwig,</p>
<p style="margin:0px 0px 1.2em!important">Just so I understand, you’d like to be able to pass the RGB volume through a color lookup table too? </p>
<p style="margin:0px 0px 1.2em!important">IMHO, if you have a RGB volume, adding a fourth component for opacity and setting an opacity function with <code style="font-size:0.95em;font-family:Consolas,Inconsolata,Courier,monospace;margin:0px 0.15em;padding:0px 0.3em;white-space:pre-wrap;border:1px solid rgb(218,218,218);background-color:rgb(232,232,232);border-radius:3px;display:inline">IndependentComponentsOff</code> is the best method.</p>
<p style="margin:0px 0px 1.2em!important"><em>Note</em> that with two dependent components, the first component values are used to lookup colors from the color transfer function i.e. the first component can be as small as 1 byte (unsigned char).</p>
<p style="margin:0px 0px 1.2em!important">Hth,<br>Sankhesh</p>
<div title="MDH:SGkgTHVkd2lnLDxkaXY+PGJyPjwvZGl2PjxkaXY+PGRpdj5KdXN0IHNvIEkgdW5kZXJzdGFuZCwg
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aCw8L2Rpdj48ZGl2PlNhbmtoZXNoPC9kaXY+PGRpdj48YnI+PC9kaXY+PC9kaXY+" style="height:0;width:0;max-height:0;max-width:0;overflow:hidden;font-size:0em;padding:0;margin:0"></div></div></div><br><div class="gmail_quote"><div dir="ltr">On Mon, Jul 10, 2017 at 10:47 AM Willy <<a href="mailto:Wiggerl@linhuber.info">Wiggerl@linhuber.info</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Hi,<br>
<br>
i want to visualize a RGB Volume and have a little problem. i do not think<br>
that there is a perfect solution, but maybe i am missing something.<br>
<br>
Here i my problem:<br>
<br>
There are three different Methods to visualize a RGB Volume:<br>
1. Method: IndependentComponentsOn: three components (R,G,B), each with<br>
Colortransferfunction and opacityfunction<br>
2. Method: IndependentComponentsOff: two components, first with<br>
Colortransferfunction and second with opacityfunction<br>
3. Method: IndependentComponentsOff: four components, 1-3(R,G,B) with<br>
Colortransferfunction and fourth with opacityfunction<br>
<br>
Here are the disadvantages for each Method:<br>
1. Method: It is not possible to create a colorTransferFunction or<br>
opacityFunction for the intensity value of a color(voxel), it is only<br>
possible to set these functions for each components seperate. This can lead<br>
to falsified colors if the user changes these functions somehow (if you<br>
have the same color and opacity function for all components).<br>
2. Method: the two components must have the same data type. the color<br>
component needs at least 3 byte, but there is no 3 byte type => 4 bytes for<br>
each component => 8 bytes per voxel => huge overhead. Moreover the image<br>
quality for maximum intensity BlendMode is not as good as for the 1. Method.<br>
If you have (in the volume) for example a green wall with value 250 and a<br>
red area behind it (for the current camera position) with value 200, you<br>
can't see the red area at all. In the first method the red area is displayed<br>
as yellow area (that is better).<br>
3. Method: No colorFunction<br>
<br>
Is there a Method without disadvantages?<br>
<br>
MfG<br>
Ludwig<br>
<br>
<br>
<br>
--<br>
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</blockquote></div><div dir="ltr">-- <br></div><div data-smartmail="gmail_signature"><div dir="ltr"><div class="inbox-markdown-here-wrapper" style="font-family:'proza libre',sans-serif;color:rgb(0,56,107)"><h5 id="inbox-sankhesh-jhaveri" style="margin:1.3em 0px 1em;padding:0px;font-size:1.1em;border-bottom-width:1px;border-bottom-style:solid;border-bottom-color:rgb(238,238,238);font-weight:bold;color:rgb(11,65,148)">Sankhesh Jhaveri</h5>
<h6 id="inbox--sr-research-development-engineer-kitware-http-www-kitware-com-518-881-4417" style="margin:1.3em 0px 1em;padding:0px;font-size:1em;color:rgb(11,83,148);font-family:'open sans',sans-serif;font-weight:normal"><em>Sr. Research & Development Engineer</em> | <a href="http://www.kitware.com/">Kitware</a> | (518) 881-4417</h6>
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