Method for locating an interproximal tooth region

A method for locating one or more interproximal regions in a digital tooth image wherein adjacent teeth have no clear demarcation, comprising:

• defining an origin point in a binary image of the digital tooth image;
• casting a fan of ray lines outward from the origin point in a plurality of angles;
• defining a contour line at points at which each ray line first encounters a boundary between tooth and background areas;
• determining internal and external markers from the binary image of the digital tooth image;
• applying a marker-controlled watershed transformation to a gradient image of a grayscale version of the digital tooth image with the internal and external markers to form first and second groups of water basins;
• and
• identifying at least a first interproximal region as those pixels having substantially the same distance to the first and second groups of water basins.

A method for locating one or more interproximal regions in a digital tooth image, comprising:

• applying a distance transformation to a binary image of the digital tooth image, to form a distance image;
• determining internal and external markers using the distance image;
• applying a marker-controlled watershed transformation to a gradient image of a grayscale version of the digital tooth image combined with the internal and external markers to form two groups of water basins;
• and
• identifying at least a first interproximal region as those pixels having substantially the same distance to the two groups of water basins.