Dear Roman and all, the itkHessianToObjectnessMeasureImageFilter in ITK Review should allow you to select the target object dimensionality (blob vs line vs plate) by calling SetObjectDimension (0 vs 1 vs 2, respectively; as a note, the filter with dimensionality 1 corresponds to Frangi's vesselness). One aspect you should be very careful about is the scale (or the scale range if you use this filter through itkMultiScaleHessianBasedMeasureImageFilter) expressed in physical units. You can get an example of the use of the filter here http://hdl.handle.net/1926/576 Hope this helps
Luca On Sep 5, 2012, at 2:41 PM, Ho Cheung wrote: > Hi Dr. Grothausmann, > > The measure in ITK appears to be based on Sato > (http://www.spl.harvard.edu/archive/spl-pre2007/pages/papers/yoshi/node3.html#SECTION00021000000000000000) > and I don't see an easy way to modify it so that it detects plate like > structures instead of line like structures. > > If speed is not a major concern for you, may I suggest you implement a > similar measure? Frangi's original vesselness enhancement formula > (http://www.dtic.upf.edu/~afrangi/articles/miccai1998.pdf) can be easily > modified for what you need and is based on Eigenvalues like Sato. > > According to equations 10, 11, 12, 13 in Frangi's paper and my interpretation > of what the measures do, what you need is high Ra, Rb, and S values, so the > formula becomes: > > V = [1 - exp(-Ra^2/2a^2)][1 - exp(-Rb^2/2b^2)][1 - exp(-S^2/2c62)] > > Hope, this helps, > > Ho Cheung > Research Assistant > Bio-Image Analytics Laboratory - University of Houston > (832) 215-6347 > > > > On Sep 5, 2012, at 3:36 AM, Dr. Roman Grothausmann > <grothausmann.ro...@mh-hannover.de> wrote: > >> Dear mailing list members, dear Luca, >> >> >> Recently I was trying to enhance vascular structures from airways with the >> vessel enhancement filters from ITK (objectness and vessel enhancement). The >> problem is that these vessels are not filled in the tomograms our imaging >> technique yields. Only the airway walls are imaged, which corresponds to an >> uneven 2D surface. Since it is only a 3D not an ND problem, I tried to >> modify itkHessianSmoothed3DToVesselnessMeasureImageFilter to enhance not >> vessels (1D) structures but plates/walls. Therefore I exchanged lambda 1 and >> 3 in the weighting function. Sadly, I could not get the filter to enhance >> the airway walls. >> Have I missed anything or would enhancing plateness this way only work for >> not-curved planes? >> >> >> Here the important part of the diff of my changes: >> >> diff -au >> itk/IJ-Vessel_Enhancement_Diffusion.1/itkHessianSmoothed3DToVesselnessMeasureImageFilter.txx >> itk/plateness3D_01/itkHessianSmoothed3DToPlatenessMeasureImageFilter.txx >> >> >> >> + ////swap Lambda1 and Lambda3 to enhance "plateness" >> + double swap_tmp= Lambda1; >> + Lambda3= Lambda1; >> + Lambda1= swap_tmp; >> + ///swapping done >> + >> double Lambda1Abs = vnl_math_abs( Lambda1 ); >> double Lambda2Abs = vnl_math_abs( Lambda2 ); >> double Lambda3Abs = vnl_math_abs( Lambda3 ); >> @@ -162,14 +168,13 @@ >> double vesMeasure_3 = >> ( 1 - vcl_exp( -1.0 * (( vnl_math_sqr( S )) / ( 2.0 * ( >> GammaSqr))))); >> >> - double vesMeasure_4 = >> - vcl_exp ( -1.0 * ( 2.0 * vnl_math_sqr( m_C )) / >> - ( Lambda2Abs * (Lambda3Sqr))); >> + double vesMeasure_4 = 1; ////plateness for now not smoothed >> + //double vesMeasure_4 = vcl_exp ( -1.0 * ( 2.0 * vnl_math_sqr( m_C >> )) / ( Lambda2Abs * (Lambda3Sqr))); ////check if this makes sense for >> plateness >> >> >> Many thanks for any help or hints. >> Roman >> >> -- >> Dr. Roman Grothausmann >> >> Tomographie und Digitale Bildverarbeitung >> Tomography and Digital Image Analysis >> >> Institut für Funktionelle und Angewandte Anatomie, OE 4120 >> Medizinische Hochschule Hannover >> Carl-Neuberg-Str. 1 >> 30625 Hannover >> >> Tel. +49 511 532-9574 >> _____________________________________ >> Powered by www.kitware.com >> >> Visit other Kitware open-source projects at >> http://www.kitware.com/opensource/opensource.html >> >> Kitware offers ITK Training Courses, for more information visit: >> http://www.kitware.com/products/protraining.php >> >> Please keep messages on-topic and check the ITK FAQ at: >> http://www.itk.org/Wiki/ITK_FAQ >> >> Follow this link to subscribe/unsubscribe: >> http://www.itk.org/mailman/listinfo/insight-users > ------------------------------------------------------------------------------ Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ _______________________________________________ vmtk-users mailing list vmtk-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/vmtk-users
