This image processing apparatus (100) acquires the ratio (α) of the pixel values between the scattered radiation reduced image (52) after the scattered radiation component is reduced and the radiation image (51) before the scattered radiation component is reduced. The pixel ratio acquisition means (23) is included, and the noise reduction means (22) for reducing the noise component from the scattered radiation reduction image based on the ratio of the pixel values is provided.この画像処理装置（１００）は、散乱線成分の低減後の散乱線低減画像（５２）と、散乱線成分の低減前の放射線画像（５１）との間の画素値の比率（α）を取得する画素比率取得手段（２３）を含み、画素値の比率に基づいて、ノイズ成分を散乱線低減画像から低減するノイズ低減手段（２２）を備える。
