Patent Number: 
Section: claims

1. An X-ray radioscopy apparatus having a grid on a front surface of a radiation detection unit for eliminating radiation from a subject, said apparatus comprising:a first extraction unit configured to extract a first grid image component arising from said grid in a first image data obtained from radiation imaging without passing through the subject;a second extraction unit configured to extract a second grid image component arising from said grid in a second image data obtained from radiation imaging through the subject;a calculation unit configured to calculate abundance of scattered component as a scalar value by comparing said first grid image component and said second grid image component; anda determination unit configured to determine an X-ray irradiation condition to reduce said scalar value calculated by said calculation unit. 2. The X-ray radioscopy apparatus according to claim 1, further comprising a storage unit configured to store an equivalence curve data table of irradiated X-ray amount related to X-ray irradiation condition,wherein said calculation unit obtains X-ray images by radiation imaging under a plurality of X-ray irradiation conditions that exist on the equivalence curve from said equivalence curve data table, and calculates said scalar values for each, andwherein said determination unit selects the X-ray irradiation condition which has the smallest scalar value among scalar values calculated by said calculation unit. 3. A method of controlling an X-ray radioscopy apparatus having a grid on a front surface of a radiation detection unit for eliminating radiation from a subject, comprising steps of:extracting a first grid image component arising from the grid in a first image data obtained from radiation imaging without passing through the subject;extracting a second grid image component arising from the grid in a second image data obtained from radiation imaging through the subject;calculating abundance of scattered component as a scalar value by comparing the first grid image component and the second grid image component; anddetermining an X-ray irradiation condition to reduce the scalar value calculated in said calculation step. 4. A non-transitory computer-readable medium storing, in executable form, a computer program for controlling an X-ray radioscopy apparatus having a grid on a front surface of a radiation detection unit for eliminating radiation from a subject, the program comprising code for performing the following steps:extracting a first grid image component arising from the grid in a first image data obtained from radiation imaging without passing through the subject;extracting a second grid image component arising from the grid in a second image data obtained from radiation imaging through the subject;calculating abundance of scattered component as a scalar value by comparing the first grid image component and the second grid image component; anddetermining an X-ray irradiation condition to reduce the scalar value calculated in said calculation step.