| 摘要 |
PROBLEM TO BE SOLVED: To improve recognizing precision by obtaining specific each reference candidate line on rectangular coordinate system to fix an area surrounded by the reference candidate lines of them as an irradiating field. SOLUTION: An irradiating field recognizing device 100 is provided with an edge candidate point detecting means 10, a reference candidate line detecting means 20 and an irradiating field deciding means 30. Then this device obtains a curve expressed by ρ=xicosθ+yisinθ at each edge candidate point by setting the coordinates xi, yi of each edge candidate point at rectangular coordinate system within a radiation picture face. Then the number of curves intersecting each other at each intersection (ρj, θj) of the obtained curves is counted to extract prescribed intersections (ρj, θj) in the order of reducing this count value. Then each reference candidate line on a rectangular coordinate system (xy coordinate system) regulated by ρj=xcosθj+ysinθj corresponding to each extracted intersection (ρj, θj) is obtained to fix the area surrounded by these plural reference candidate lines as the irradiating field. |
