| 摘要 |
PROBLEM TO BE SOLVED: To observe an image in an image area to be observed with high contrast by using a histogram equalization method thereby converting a histogram of a density level of picture elements of an image in an attentional area. SOLUTION: When an instruction signal denoting automatic conversion of gradation of an image in the attentional area is given to a gradation transformation execution means 110, an image data read section 202 reads a coordinate value of corresponding graphic data stored in a coordinate data storage section 200 and provides an output of the coordinate to a histogram calculation section 204. The calculation section 204 calculates a histogram of a gray level of pixels according to a received gradation transformation execution signal and provides the calculated histogram to a gradation transformation curve generating section 206. The generating section 206 coverts the received histogram. A gray level conversion section 208 converts a density level of each picture element of the image data corresponding to the image in the received concerned area and provides an output of the converted image data to a window memory 84. |
