Patent ID: 6900801

Claim:
An apparatus for detecting an edge in a three-dimensional image, comprising: a scan-line approximation unit creating an approximated quadratic curve with regard to each scan-line corresponding to each surface of the three-dimensional image by scanning the three-dimensional image in a set-up direction; a curvature value calculation unit calculating approximated curvature values with regard to each division point estimated as different surfaces of the three-dimensional image on the quadratic curve approximated from the scan-line approximation unit; and an edge decision unit deciding an edge by comparing the approximated curvature values of the division points calculated from the curvature value calculation unit with a predetermined threshold, wherein the curvature calculation unit calculates the curvature values of the division points through a mathematical expression represented by; k ❘ x = x 0 = ⅆ θ ⅆ S ❘ x = x 0 = tan - 1 ⁢ ( f 2 ′ ⁢ ( x 2 ) ) - tan - 1 ⁢ ( f 1 ′ ⁢ ( x 1 ) ) 2 where k is a curvature value, x 0 is a division point on a quadratic curve, x 1 is a point placed at left as much as a length of a unit arc from the x 0 point on a quadratic curve, x 2 is a point placed at right as much as a length of a unit arc from the x 0 point on a quadratic curve, θ is a tangent angle of lines of two functions forming the division point, and S is a length of an arc.