Figure 5.

Ambiguity of affine image alignment due to non-uniform leaf motion. In addition to global geometrical transformations, such as image scaling, translations and rotations, plants exhibit uncorrelated motion of leaves which can not be compensated by a single affine alignment. (A) Diagonal (T₁₁), off-diagonal (T₁₂), and translational components (T₃₁, T₃₂) of the affine transformation matrix determined for different scale factors undergo considerable variation which reflects ambiguity of affine alignment of structurally non-identical images. (B) Single-step PC registrations of differently scaled images (S_i) may lead to partial overlaps of different parts of the plant. In order to improve accuracy of PC registration of non-uniformly moving plant structures, the results of multiple registrations are integrated into a single integrated mask (IM) which provides significantly better coverage of the entire plant shoot in FLU and VIS images.