Image processing method for automatic adaptation of 3-D deformable model onto a substantially tubular surface of a 3-D object

摘要

An image processing method, comprising acquiring an image of a 3-D tubular object of interest to segment; computing a 3-D path that corresponds to the centerline of the tubular object and defining segments on said 3-D path; creating an initial straight deformable cylindrical mesh model, of any kind of mesh, with a length defined along its longitudinal axis equal to the length of the 3-D path; dividing this initial mesh model into segments of length related to the different segments of the 3-D path; computing, for each segment of the mesh, a rigid-body transformation that transforms the initial direction of the mesh into the direction of the related segment of the 3-D path, and applying this transformation to the vertices of the mesh corresponding to that segment. The method comprises avoiding self-intersections in the bent regions of the tubular deformable mesh model and sharp radius changes from one segment of the mesh model to the other, by adapting or modulating the radius of the cylindrical deformable mesh model according to the local curvature of the 3-D path, sample distance of the path points and a predefined input radius.

主权项

1. An image data processing method of automatic adaptation of 3-D surface model to image features, for model-based image segmentation, the method comprising:
creating a deformable tubular mesh model for fitting a 3-D path based on a centerline of a 3-D tubular object of interest, the 3-D path comprising a set of ordered points defining a plurality of path segments, the mesh model having an initial radius and comprising a plurality of mesh segments corresponding to the plurality of path segments; determining, for each mesh segment, a value that is a product of the initial radius and a local curvature of the corresponding path segment; and automatically adapting a length of a mesh radius for each mesh segment having the value greater than one, by applying a shrinking factor to the initial radius, wherein the shrinking factor is a constant value for each of the mesh segments to be adapted, the constant value being less than one and based on the initial radius and the radius of local curvature of the corresponding path segment, wherein automatically adapting the mesh radius comprises,
modulating the initial radius of the deformable tubular mesh model according to a local curvature of the 3-D path to limit self-intersections between bent portions of the deformable tubular mesh model;approximating the local curvature, andapplying a radius modulation technique comprising a bi-cubic spline interpolation from one radius to another.