An image processing apparatus that can convert an interlaced signal generated by the 3-2 or 2-2 pull-down process, to a progressive signal without degrading the quality of the image represented by the interlaced signal, even if the interlaced signal contains an ordinary 60-fields/sec signal. The apparatus has a progressive conversion unit 11. The progressive conversion unit 11 generates an intra-field interpolated signal and an a motion-adaptive interpolated signal to convert an interlaced signal generated by the 3-2 or 2-2 pull-down process and containing an ordinary 60-fields/sec signal, to a progressive signal. The unit 11 then determines, for each pixel, whether the intra-field interpolated signal contains a double-image error. If a double-image error is detected, the unit 11 replaces, for each pixel, the intra-field interpolated signal by the motion-adaptive interpolated signal.