PURPOSE: To protect erroneous discrimination of edge area by obtaining an edge quantity for discriminating whether a relevant picture element is in an edge area, and by controlling the mixture of the smoothing component and the edge intensifying quantity by whether or not the edge quantity exceeds a threshold value.

CONSTITUTION: In a half tone data restore section 101, a restore data calculating section 114, based on the pseudo half tone binary image data to be input, generates the max absolute value data of edge discrimination quantity. Further, a smoothing value calculating section 112 calculates an average value obtained by smoothing picture elements data within a predetermined area and outputs it to a restore data calculating section 114. In this constitution, when obtaining an edge intensifying quantity in the edge intensifying direction, the image processor detects an edge component from the difference between the number of picture elements in two windows. Here, the edge quantity is obtained, and the mixture of the smoothing component and the edge intensifying quantity is controlled by whether the edge quantity exceeds a threshold value. This control makes it possible to reduce erroneous discrimination for edge area.