Motion adaptive pro-scan converter with two dimensional contour enhancement

To effectively suppress deficiencies associated with the interlaced scanning, which yields a poor result in terms of the vertical picture resolution, a practical motion adaptive pro-scan line interpolator was developed. The system is composed of an intrafield interpolator, an interfield interpolator, three contour compensation filters, and a motion detector. For still pictures, the interpolated lines of the previous field are properly delayed and intermingled with the scanning lines of the actual field, in order to up convert the vertical sampling rate. When moving pictures are present, the scanning lines of the up-converted frames are obtained by switching the outputs of the intrafield interpolator. The progressive commutation between the interfield and intrafield interpolation processes is controlled by a motion detector with a frame averaging filter. In the proposed system, each line averaging filter acts mainly as a vertical low-pass filter which, together with the corresponding horizontal low-pass filter, constitutes the core of the contour compensation circuit