Abstract
In variable speed playback of a composite video tape recorder (VTR), the reproduced video must be converted to a standard TV signal because fields in the reproduced video are skipped or repeated. For field conversion processing, a Y/C separation circuit and a line-interpolation circuit are used. In a conventional processor, the picture quality deteriorates due to vertical displacement of the image and lower resolution. Our new motion-adaptive field-conversion circuit that uses inter-field signals can remove these deficiencies. The focus of this paper is on a motion-adaptive line-interpolation technique. It also describes a new line-interpolation filter with a motion detection function that compares the amplitude of inter-field signals. Based on these techniques, three kinds of gate arrays were developed. The arrays were employed in D-2 VTR for NTSC signals. This VTR exhibits none of the problems mentioned above and has picture quality comparable to that at standard play-back speed.
