| 摘要 |
PURPOSE:To calculate a more accurate binarizing threshold value not by making a binary decision on whether or not the pattern of a model, etc., of an image edge is normal, but by deciding adaptability including intermediate information. CONSTITUTION:A window having a specific range is set on a multi-level image and image data is supplied to a histogram generation part 23 and an illegal pattern histogram generation part 22. The illegal pattern histogram generation part 22 generates a histogram as to the degree of illegality obtained by subtracting one from the maximum value among values of adaptibity in eight directions wherein a proper binary-coding process can be performed by using a membership function found based on the difference in brightness between the center picture element in the window and its peripheral picture elements. A picture quality histogram generation part 24 divides the output value of the illegal pattern histogram generation part 24 by the output value of a brightness histogram generation part to perform normalization and a picture quality histogram is obtained as a criterion. |
