I applied SHPARM-PDM extension, and then obtained the coefficients of spherical harmonic.

I wonder if I can reconstruct the original mode by just use the coefficients.

Yes, you can. You need to sample the spherical parametrization space and then evaluate the spherical harmonic series at those sample. SlicerSALT is doing that already for you, by using a spherical sampling scheme based on an icosahedron subdivision. The tool that does this is called ParaToSPHARMPDM, which first fits the coefficients and then generates a reconstructed surface from those coefficients.

Martin

Dear Martin,

Thank you for your response.

Actually, I have tried to reconstruct the shapes by the output the spherical harmonic coefficients

.

Just generated the series of spherical harmonics for each v(phi, theta), and then multiply the coefficients.

However, the result shape is just like a surface.

Because I am trying to develop a tool to apply the spherical harmonic coefficients

.

I wonder if I miss any other parameters.

Cheng

Martin Styner via 3D Slicer Community slicer@discoursemail.com 於 2019年10月25日 週五 上午4:40寫道：

Not sure what may be wrong in your reconstruction code, but you can look at the code in SlicerSALT:

surface reconstruction:

SPHARM reconstruction at phi/theta:

(look at function Evaluate)

Martin

Dear Martin,

Thanks a lot.

Originally, I implemented my code by Python and apply scipy.special.sph_harm and np.linalg.lstsq to solve the coefficients.

It might have some differences in the details.

I think I can start to modify my code by reference your code.

Regards

Cheng

Regards

Cheng

Martin Styner via 3D Slicer Community slicer@discoursemail.com 於 2019年10月25日 週五 下午10:52寫道：