I am reading about active contours models. It is said that this can be broadly classified as either parametric active contour models and geometric active contour models. The first one are represented explicitly as parameterized curves in a Lagragian framework, while the geometric active contours are represented implicitly as level sets of a 2-dimensional function that evolves in a Eulerian framework.
What is an Eulerian approach and an Lagragian approach?
Thanks,