| 摘要 |
PURPOSE: To exactly extract the part of a blood vessel in an image measuring a diagnostic part by reading tracking candidate points on a tracking candidate line selected by using the average density value of a line from a calculated attention point as attention points, and tracking the blood vessel up to the conditions of tracking end. CONSTITUTION: A point P and a direction D are the attention point and a tracking direction and become a tracking start point and a tracking start direction inputted from an input device when starting tracking, a radial straight line toward the circle of a radius with the attention point P as a center within the range of ±π/2 from the tracking direction D is calculated and its average density value is calculated. A weighing function equipped with a peak in the tracking direction D is multiplied to this average density value and a direction Dn, in which this weighed average density value is maximum, is selected as the tracking direction. Then, tracking candidate points Pn on the circumference in the direction Dn are read as the attention points and with the tracking candidate points as the attention points, tracking is repeated up to the tracking end conditions. Therefore, the main part of the blood vessel is exactly tracked without erroneously tracking a branch 127 or a noise 28 of the blood vessel. |
