PROBLEM TO BE SOLVED: To obtain an X-ray image which includes much internal information of a subject, and is suitable for observation.SOLUTION: The radiation imaging apparatus includes: an X-ray sensor 102 for irradiating the subject 1000 with an X-ray from an X-ray generating part 101, and photographing the X-ray image A based on a transmission X-ray 101b transmitting the subject 1000 a histogram calculating part 103 for calculating a histogram concerning the respective pixel values of the X-ray image A and an X-ray irradiation condition determining part 104 for determining the X-ray irradiation condition of the irradiation X-ray 101a to be radiated from the X-ray generating part 101, so as to allow the distribution of the histograms to be flat.COPYRIGHT: (C)2010,JPO&INPIT【課題】被写体の内部情報をより多く含む、観察に適したX線画像の取得を実現できるようにする。【解決手段】X線発生部101から被写体1000にX線を照射して、被写体1000を透過した透過X線101bに基づくX線画像Aの撮像を行うX線センサ部102と、X線画像Aの各画素値に係るヒストグラムを算出するヒストグラム算出部103と、ヒストグラムの分布が平坦となるように、X線発生部101から照射する照射X線101aのX線照射条件を決定するX線照射条件決定部104を有する。【選択図】図1
