To provide an image distortion correction apparatus capable of correctly deciding the presence of thin ruled lines and ruled lines on which skew remains, resulting in that the image quality of a corrected image can be improved.

The image distortion correction apparatus extracts rectangles including black pixels each with a predetermined threshold or below in a main scanning direction configuring ruled lines and selects rectangles including ruled lines utilized for distortion correction of a scanned image among thin and long rectangles in the sub scanning direction. Since the image distortion correction apparatus can correctly decide the presence of the thin ruled lines and the ruled lines on which skew remains and enhance the frequency of distortion correction by utilizing the ruled lines of the image wherein the ruled lines exist, the image quality of the corrected image can be improved as a result.

COPYRIGHT: (C)2005,JPO&NCIPI