| 摘要 |
PURPOSE:To attain the conversion of density with high density resolution for a noticed area by setting density conversion characteristics based on density information within a range of information on a reproduced picture and performing the density conversion of the picture information according to said conversion characteristics. CONSTITUTION:A thoracic X-ray photograph contains many low-density areas owing to the presence of bones, a mediastinum, etc. Therefore, the low density area has a larger density distribution than a high density area as shown by a curve T. While the density distribution has a higher rate comparatively at the side of a high-density area in a noticed area A as shown by a curve A1 because a lung field exists there. In this connection, the density conversion characteristics are set as shown by a curve A2 based on the density information within a range (b) of the reproduced picture information corresponding to the area A. Thus it is possible to obtain the density information having an output density distribution curve A3 where the density is converted from a noticed area (b) into a density identifiable area (c). Thus a reproduced picture having high density resolution can be displayed on the area A. This eliminates the conventional setting method based on trials and errors and reduces the time needed for conversion of density. |
