[Insight-users] Re: Jacobian determinant image of the deformation field

[Tom Vercauteren]

Hi Mathieu,

Just my two cents about it. I do agree with you that the current
implementation is not computing a really meaningful quantity. However,
the current name is misleading. Without adding an Id matrix, it
actually computes the Jacobian of the deformation field, but what we
usually need is the Jacobian of the spatial transformation... In my
code, I have added an itk::WarpJacobianDeterminantFilter to make
things a bit clearer.

Best,
Tom

On 9/6/07, Mathieu De Craene <decraene at tele.ucl.ac.be> wrote:

Hi ITK folks,


I found this email on the mailing list

        http://public.kitware.com/pipermail/insight-users/2006-August/019246.html

and I think these two users are right.

I was wondering if we shouldn't add the following line at line 250 of
itkDeformationFieldJacobianDeterminantFilter.h to correct the problem

        if (i == j) J[i][j] += 1.;


so that we effectively compute


        det[ dT/dx ] = det[ I + du/dx ]



Thanks for any comment,



Mathieu