The plusend filaments under tracing is represented
as an ordered point sequence
The point sequence is then modeled with second order
prior dynamics that allow appropriate balance between smoothness and
flexibility.
Using Bayesian rules and Markovian hypothesis, the
tracing is to find the most probably next point based on the posterior
recursion
The posterior can be approximated by sampling
The weights are given by the
likelihood
The prediction is given by
the prior dynamics
where R is a rotation
matrix.
Since plusends
filaments are unlikely to have inflections, we approximate the mean tracing
direction change by fitting a parabola segment to a set of traced points.
The tracing direction change is then modelled by a normal distribution
The likelihood is calculated from the similarity between the intensity at the predicted
point and
the intensity of the microtubule wall:
The intensity of the microtubule wall is estimated as
a Gaussian distribution based on the segmented microtubule body in previous
step.
