Method and system for determining a boundary surface network

A boundary surface network determination system for determining a boundary surface network of a tubular object, comprising

• an input interface, configured to supply an ordered series of contours on the basis of image data;
• a segment object determination unit including a computer system configured to execute computer-readable instructions to
• specify a transformation function for respectively transforming consecutive contours in the ordered series of contours from a source space into a unit space, the unit space being a three-dimensional Euclidean space having a normalized length, width and height, and which is different from the source space, and
• create a unit space segment object in the unit space on the basis of the consecutive contours;
• a distance determination unit, configured to determine a separation from a unit space segment object on the basis of a signed distance function established for each segment object in the unit space;
• a position determination unit, configured to determine relative positional information of a query point in the source space from a surface of a segment object in the source space, said segment object being based on the consecutive contours, on the basis of the local signed distance function;
• and
• an output interface, configured to supply a boundary surface network on the basis of a multiplicity of relative positional information determined via the position determination unit;
• wherein the contours are freeform contours.