There is only one set of initial parameters construed for AffineRegistration. Hence this set has the form [ 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0 ] (identity matrix for rotation column-wise and zero offset ).
If some rigid transformation is selected, only the first 6 parameters are taken into account (since 6dof optimization). The initial rotation in x has the value 1 rad ( 57 deg ) which makes the registration problem 'ill-posed'.
| Status | Assigned | Task | ||
|---|---|---|---|---|
| Resolved | None | T14638 [Metabug] Diffusion test results | ||
| Resolved | None | T14627 Rigid registration is initialized with wrong parameters |
The responsible code part is the following method
ImageRegistrationMethodAccessFunctor::AccessItkImage
lines 106 - 121 ( zeroInitial variable )
which does not distinguish between the different transformation types and their initial positions ( resulting into identity transformation ) correctly.
[e58788]: Merge branch 'bug-14627-Fix-initial-parameter-in-registration'
2013-03-06 14:48:59 Jan Hering [6e9d2c]
Fixing transform parameter setting for registration