| 摘要 |
PURPOSE:To decide a circular pattern with high accuracy by comparing the 1st characteristic value with the 2nd characteristic to decide whether a prescribed picture element is included in a circular pattern or not and thereby separating the circular pattern from a linear pattern with high accuracy via a single filter only. CONSTITUTION:Each difference i (i=1, 2... n) is obtained between the average value QO corresponding to many picture elements including a prescribed picture element PO and stored in a center area and the average value Qi (i=1, 2... n) corresponding to the picture elements Pi - Pn of each peripheral area. Then the 1st characteristic value representing many difference i is obtained together with the 2nd characteristic value showing the variance of many difference i. Then the ratio is obtained between both characteristic values and compared with the prescribed threshold values to device whether the picture element PO is contained in a circular pattern or not. Thus it is possible to separate the circular pattern from a linear pattern with high accuracy via a single filter and then to device with high accuracy whether the element PO designated on an radiation image is included in the circular pattern or not. |
