Method of recognizing irradiation field, and method of adjusting image processing conditions

摘要

In a method of recognizing an irradiation field, image signals at respective positions on a recording medium are detected based on image information detected from the recording medium, and X and Y axis are set along two adjacent sides of a contour of a rectangular irradiation field on the recording medium. The image signals are added up in the X and Y axis directions respectively, and Y axis positions at which levels of added-up signals in the X axis direction are equal to a threshold value and X axis positions at which levels of added-up signals in the Y axis direction are equal to the threshold value are detected. A region surrounded by straight lines passing through these positions along the X and Y axes is recognized as the irradiation field. In the method of adjusting image processing conditions, the image processing conditions are adjusted based on the image information inside of the irradiation field thus recognized.