Algorithm 1.

Vessel Segmentation

Require: Enhanced epifluorescence-based vessel image I

Ensure: Background-Vessel mask MaskVessel (1:Vessel, 0:BG)

1: ℋ(I)←Hessian(I)

2: g(∇I) = exp(−|∇Gσ(x, y) * I(x, y)|) // Edge stopping function

3: FA(x, y) = c1 × (trace(ℋ(I(x, y))) + c2) // Differential geometric adaptive force

4: Maskridge(x, y)←Initialize ridge mask

5: Maskridge(trace(ℋ) < ε)←1 // Set ridge (vessel) pixels to 1

6: Maskridge = Maskridge ⊕ se // Dilate ridges

7: ϕ = SignedDist( Maskridge) //Initialize ϕ using signed distance transform of Maskridge; Maskridge = = 0→ϕ > 0

8: while stopping/convergence condition not met do

9: Evolve ϕ using g(∇I) and spatially adaptive force FA.

10: end while

11: MaskVessel(x, y)←0; MaskVessel(ϕ < 0)←1 // 1: Vessel, 0:BG