Abstract: A video signal recording and reproducing system enables recording and reproducing of a video signal with high quality. The system includes a recording system for recording the video signal on a record medium by means of a median filter and a reproducing system for reproducing the video signal from the record medium. The recording system separates a brightness signal and a color signal from an interlaced scanning signal. The recording system divides picture elements of each line into two phases by sorting the elements such that an element is put into one phase and the next element into the other. The recording system then carries out two-dimensional subsampling to the brightness signal and the color signal to reduce the amount of data. Then, the recording system compresses and time-division multiplexes the brightness signal and the color signal to provide a video signal to be recorded onto a record medium.

Abstract: An HDTV signal (dot density: 2N dots/line) is converted into a luminance signal and a line sequential color signal, and the resulting signals are both subjected to vertical interpolation and vertical filtering to derive a sequential scanning luminance signal and a sequential scanning color signal. The resulting sequential scanning luminance signal and sequential scanning color signal are subjected to frame thinning to reduce the frequency thereof to a half. Then, subsampling is performed to reduce the dot density to N dots/line. Next, dot rearranging for distributing adjacent dots to adjacent lines is performed to double the number of frames, whereby the dot density of each frame is reduced to N/2 dots/line. These consequently derived frames are encoded for recording. In this manner, the frequency bandwidth required to a recording medium for recording HDTV signals can be reduced.

Abstract: A frequency converter circuit for converting the frequency of a Hi-Vision carrier chrominance signal into the frequency of an NTSC signal includes a buffer memory wherein color signal data are written in according to a writing signal derived from the Hi-Vision (source) subcarrier frequency, and color signal data are read out according to a reading signal derived from the NTSC (target) subcarrier frequency. The reading signal may correspond to a delayed writing signal, which is delayed by a time derived from the target subcarrier frequency.