<br>Hi Michael,<br><br>Assuming that you are doing this just for the purpose of providing<br>an image for visualization, as opposed to an image that is going <br>to undergo further processing...<br>
<br><br>You can build a quick sharpen filter by taking the original image<br>and subtracting from it its smoothed version.<br><br><br>From the spectral point of view, this is equivalent to removing<br>low frequencies from the image, hence equivalent to enhancing<br>
high spatial frequencies.<br><br>You may want to go a step further and multiply the smoothed<br>image by a constant to get some control on how much you<br>attenuate the low frequencies.<br><br>In pseudocode you end up with<br>
<br><br> Sharpened image = Image - K . Smoothing( Image, Sigma )<br><br><br> Typically K will be in the range [0,1].<br><br><br>and... you may want to go with a large Sigma, (e.g. spanning<br>more pixels than the details that you want to enhance).<br>
<br><br><br><br> Regards,<br><br><br> Luis<br><br><br>--------------------------------------------------------------------------------<br><div class="gmail_quote">On Tue, Jun 9, 2009 at 9:34 AM, Michael Knopke <span dir="ltr"><<a href="mailto:Michael.Knopke@gmx.de">Michael.Knopke@gmx.de</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
<div link="blue" vlink="purple" lang="EN-US">
<div>
<p>Hi ,</p>
<p> </p>
<p>Thanks for the hint David, that’s what I want to do
later (needs bridging between vtk-itk first).</p>
<p>I just wanted to have some simple sharpen filter to apply
onto the image (just like vtkImageGaussianSmooth but for sharpening).</p>
<p>I know about vtkButterworthHighpass, but this is no option
since it is terrible slow…</p>
<p>Anybody else?</p>
<p> </p>
<p>Michael</p>
<p> </p>
<p> </p>
</div>
</div>
<br>_______________________________________________<br>
Powered by <a href="http://www.kitware.com" target="_blank">www.kitware.com</a><br>
<br>
Visit other Kitware open-source projects at <a href="http://www.kitware.com/opensource/opensource.html" target="_blank">http://www.kitware.com/opensource/opensource.html</a><br>
<br>
Please keep messages on-topic and check the VTK FAQ at: <a href="http://www.vtk.org/Wiki/VTK_FAQ" target="_blank">http://www.vtk.org/Wiki/VTK_FAQ</a><br>
<br>
Follow this link to subscribe/unsubscribe:<br>
<a href="http://www.vtk.org/mailman/listinfo/vtkusers" target="_blank">http://www.vtk.org/mailman/listinfo/vtkusers</a><br>
<br></blockquote></div><br>