IMAGE PROCESSING APPARATUS, METHOD AND STORAGE MEDIUM

There is disclosed an image processing apparatus. A contour interval intended to be extracted is designated (S1). A start point designated in S1 is used as the initial position of an attended point, and an end point is set as a target point of contour tracing (S2). A positional relation of the attended point and the target point is calculated (S3). A blind mask for blinding pixels in the vicinity of the attended point is prepared (S4). This mask processing permits a considerably free contour line tracing, while setting a restriction to securely converge to the target point. The pixel with the maximum edge strength is searched for from the pixels in the vicinity of the attended point (S5), and the searched contour pixel is set as a new attended point (S6). The operation is repeated from S3 to S6 until the new attended point reaches the target point (S7).