In order does noise decrease processing without in addition making the edge of the picture signal become dim, without depending on signal-to-noise ratio quality, to indicate in fixed picture quality, the luster scanning the medical picture, it reads the digital x-ray graphics data and (S301), making use of the similarity threshold P which considers signal-to-noise ratio quality in every notice pixel it decides and (S302 - S304) whether the picture signal component or the noise component, the processing which receives the decision result that the picture signal component to the notice pixel (S305), or the processing which receives the decision that the noise component (S306), either one it administers one side.ディジタルX線画像データをS/N特性に依存することなく、また画像信号のエッジ部をボケさせることなくノイズ低減処理を行い、一定の画質で表示するために、医用画像をラスタ走査して読み込み(S301)、着目画素毎にS/N特性を考慮した類似性閾値Pを用いて画像信号成分かノイズ成分かを判定し(S302~S304)、着目画素に画像信号成分との判定結果を受けた処理(S305)、またはノイズ成分との判定を受けた処理(S306)、のどちらか一方を施す。
