Figure 2

Visualization of different coordinate systems with example data. PCS: Patient based coordinate system (manual delineation line). ICS: Image coordinate system (volume data). de-rotated PCS: de-rotated patient based coordinate system with same scale and origin as PCS but same orientation as ICS (de-rotated best fitting ellipse dBFE _nl , de-rotated control points dCP _n ). sample space: The transformation matrix Λ dCP n maps the de-rotated data {dBFE _n ,dCP _n } to $\{{\overline{\mathit{\text{BFE}}}}_n,{\overline{\mathit{\text{CP}}}}_n\}$ in the sample space.