
250 Image Analysis and Modeling in Ophthalmology
two-dimensional images into a line parameter domain. Each line in the original image
will yield a peak in the transform domain; the position of this peak indicates the corre-
sponding line parameters [21]. Hence, lines within images are transformed into points in
the Radon domain.
Mathematically, a line can be expressed as: ρ = x × cos θ + y × sin θ, where θ is a line
angle and ρ is the offset from the origin of the coordinate system.
Given a continuous function g(x, y), the Radon transform is dened as:
Rg gs
ρθ ρθ θρ
α
α
,cos sin, sincos
()
=−+
−
+
d (14.1)
Equation 14.1 describes an integral f ...