| 摘要 |
PURPOSE:To finish a pulmonary field area which is a concerned area with a contrast easy to see without being influenced by the size of the heart superposed with the pulmonary field part in a chest radiographic image. CONSTITUTION:On the basis of an image signal read as a radiographic quantity in a human body chest party, the pulmonary field area and mediastinum area in an image are recognized in a pulmonary field/mediastinum recognizing part 21. In an area ratio detecting part 22, then, the number of picture elements contained in the respective areas are counted, whereby the area ratio between both the areas is determined. In a gradation processing condition determining part 23, the gradation processing condition is variably set so that the contrast on low signal side is higher when the area of the mediastinum area is relatively large. By determining the gradation processing condition, the contrast in the superposed part is enhanced when the heart is large and the pulmonary part superposed with the heart is large, and the pulmonary part of the concerned area is finished with a gradation easy to see. |
