Smooth gray-level based surface interpolation for an isotropic data sets

A method of locating, relative to a source point, a closest target point on a surface of an object in three-dimensional space, wherein the object is represented by a decision rule and plurality of volume elements arranged in slices comprising rows and columns, wherein each volume element carries at least one value, and wherein the decision rule determines membership of each volume element to the object in accordance with the at least one value of the volume element, the method comprising:

• determining a contour of a representation of the object within each slice;
• locating on the contour of each slice a homing point closest to the source point;
• fitting a curve to the located homing points;
• and
• identifying a point on the fitted curve closest to the source point as the closest target point.

An apparatus for determining a distance of a source point to a surface of an object in three-dimensional space, wherein the object is represented by a decision rule and a plurality of volume elements arranged in slices comprising rows and columns, wherein each volume element carries at least one value, and wherein the decision rule determines membership of each volume element to the object in accordance with the at least one value of the volume element, the apparatus comprising:

• a processor and memory;
• logic stored in memory and executable by the processor, said logic comprising
• logic for determining a contour of a representation of the object within each slice;
• logic for locating on the contour of each slice a homing point closest to the source point;
• logic for fitting a curve to the located homing points;
• and
• logic for determining a distance from the source point to the fitted curve as the distance to the surface of the object.

An apparatus for locating, relative to a source point, a closest target point on a surface of an object in three-dimensional space, wherein the object is represented by a decision rule and a plurality of volume elements arranged in slices comprising rows and columns, wherein each volume element carries at least one value, and wherein the decision rule determines membership of each volume element to the object in accordance with the at least one value of the volume element, the apparatus comprising:

• a processor and memory;
• logic stored in memory and executable by the processor, said logic comprising
• logic for determining a contour of a representation of the object within each slice;
• logic for locating on the contour of each slice a homing point closest to the source point;
• logic for fitting a curve to the located homing points;
• and
• logic for determining a point on the fitted curve closest to the source point as the closest target point.

An apparatus for registering a plurality of source points to a surface of an object in three-dimensional space, wherein the object is represented by a decision rule and a plurality of volume elements arranged in slices comprising rows and columns, wherein each volume element carries at least one value, and the decision rule determining the membership of each volume element to the object in accordance with the at least one value of the volume element, the apparatus comprising:

• a processor and memory;
• logic stored in memory and executable by the processor, said logic comprising
• logic for determining a contour of a representation of the object within each slice;
• logic for determining a target point for each of the plurality of source points;
• and
• logic for adjusting the plurality of source points to the corresponding target points;
• wherein the logic for determining a target point for each of the plurality of source points comprises:
• logic for locating on the contour of each slice a homing point closest to a source point;
• logic for fitting a curve to the located homing points closest to the source point;
• and
• logic for determining a point on the fitted curve closest to the source point as a target point.