| US 7,570,792 B2 | ||
| Image processing apparatus and control method and program therefor | ||
| Naoto Takahashi, Utsunomiya (Japan) | ||
| Assigned to Canon Kabushiki Kaisha, Tokyo (Japan) | ||
| Filed on Jan. 31, 2005, as Appl. No. 11/45,283. | ||
| Claims priority of application No. 2004-028532 (JP), filed on Feb. 04, 2004. | ||
| Prior Publication US 2005/0169534 A1, Aug. 04, 2005 | ||
| Int. Cl. G06K 9/00 (2006.01) | ||
| U.S. Cl. 382—132 [250/363.01; 250/370.09] | 5 Claims |
| 1. An image processing apparatus which extracts an irradiation field area whose overall size is a circle shape or a square
shape, in an image taken by radiography, comprising:
first irradiation field recognition means for extracting a closed curve obtained by connecting a plurality of irradiation
field end candidate points as a perimeter of the irradiation field area in the image;
shape analysis means for determining whether an overall shape of the irradiation field area extracted by said first irradiation
field recognition means is a circle shape or a square shape on the basis of the perimeter or an area surrounded by the perimeter;
and
second irradiation field recognition means for extracting an overall shape of the irradiation field area as a circle shape
when said shape analysis means determines that the overall shape of the irradiation filed area is the circle shape, and extracting
an overall shape of the irradiation filed area is the square shape when said shape analysis means determines that the overall
shape of the irradiation filed area is the square shape.
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