To provide a digital image processing apparatus and method for preventing moire patterns from being generated without deteriorating a reproduced image with a simple circuit.

A complementary calculation unit 200 finds seven virtual sampling points which are identical to image data in sampling frequency but different in phase by complementary calculation. When it is determined that the current pixel is an edge portion by an image edge detecting unit 230, an image complementary data selecting unit 250 outputs image data which was subjected to filter processing for emphasizing the edge by an image edge emphasizing unit 240 to a subsequent stage. When it is determined that the current pixel is not an edge portion, and only when peal point or valley point is one respectively, the point is assumed to be a representative value. In other cases, the point of actual sampling is assumed to be a representative value. When forming an image, points to be plot-outputted are switched for every pixel by a position of above representative value.