Dear Michel, dear Luca,
Coming back to Hessian-based measures of Yours, which I've tried out two years ago: Is my understanding correct that the response function V of [Descôteaux et. al.MICCAI 2006] and [Luca ITK-Journal 2007] differ for N=3 and M=2? i.e. for N=3, M=2: Rblob = vnl_math_abs( l3 + l3 - l2 - l1 ) / l3 in itkDescoteauxSheetnessImageFilter corresponding to Ra (NOT Rb) in itkHessianToObjectnessMeasureImageFilter, which is undefined for N=3, M=2. Rsheet = l2 / l3 in itkDescoteauxSheetnessImageFilter corresponds to Rb in itkHessianToObjectnessMeasureImageFilter, both equal for N=3, M=2. When has each definition its optimal use? Additionally, In Descôteaux2006 a zero level-set segmentation approach is described based on a vector field constructed from initial ellipsoids positioned at high sheetness measures. Are there ITK-Filters to achieve that same approach or something similar? Which would I need? Many thanks again for Your replies and help. Roman On 05/09/12 17:10, Audette, Michel A. wrote: > Do a google on sheetness. Maxime Descôteaux and I had modified this type of > operator a few years back to improve the detection of curviplanar bones > (MICCAI > paper, republished in J. Computer Assisted Surgery), which was a tweak of his > and Frangi's work on vesselness operators. > > Michel > > Michel Audette, Ph.D. > Assistant Professor, > Department of Modeling, Simulation and Visualization Engineering, > Old Dominion University, > Norfolk, VA. > ________________________________________ > From: insight-users-boun...@itk.org [insight-users-boun...@itk.org] on behalf > of > Ho Cheung [hocheun...@gmail.com] > Sent: Wednesday, September 05, 2012 8:41 AM > To: Dr. Roman Grothausmann > Cc: insight-us...@itk.org; vmtk-users@lists.sourceforge.net; Luca Antiga > Subject: Re: [Insight-users] enhancing plate like structures (by modifying > itkHessianSmoothed3DToVesselnessMeasureImageFilter) > > 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 > > _____________________________________ > 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 > > > -- > BEGIN-ANTISPAM-VOTING-LINKS > ------------------------------------------------------ > > Teach CanIt if this mail (ID 699566122) is spam: > Spam: > https://www.spamtrap.odu.edu/b.php?i=699566122&m=6758d860fb26&t=20120905&c=s > Not spam: > https://www.spamtrap.odu.edu/b.php?i=699566122&m=6758d860fb26&t=20120905&c=n > Forget vote: > https://www.spamtrap.odu.edu/b.php?i=699566122&m=6758d860fb26&t=20120905&c=f > ------------------------------------------------------ > END-ANTISPAM-VOTING-LINKS > -- 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 D-30625 Hannover Tel. +49 511 532-9574 ------------------------------------------------------------------------------ _______________________________________________ vmtk-users mailing list vmtk-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/vmtk-users
