Abstract: A 3.times.3 sub-band coding-decoding circuit for coding and decoding video signals and a method thereof includes: a horizontal dividing section, a vertical dividing section, a vertical synthesizing section, and a horizontal synthesizing section. The transmitting signals are divided into a horizontally compressed low band, a horizontally compressed medium band and a horizontally compressed high band. From these three bands, first to sixth bands (LL-HL) are formed. At the receiving section, the six bands are restored into three bands, i.e., a vertically restored low band, a vertically restored medium band and a vertically restored high band. Then the three restored bands are finally restored to the form before the coding by expanding the horizontal components and by adding them together.

Abstract: A convertor for converting a sub-sample television signal such as MUSE signal, which is obtained from a high density television signal by way of offset sub-sampling the horizontal scan lines of the high density television signal and time compressing the transmission band, to a standard television signal includes odd field and even field vertical filters for filtering odd lines and even lines in the MUSE signal, and time base expanders for selecting predetermined lines from the lines filtered by the odd and even field vertical filters and for expanding on time base the selected predetermined lines. Also, another vertical filter is provided for processing the signal from the time base expanders according to the sub-sampling phase.

Abstract: Motion compensated coding of interlaced digital video signals is provided. Pixel data from successive interlaced video fields is compared to similarly situated pixel data in a plurality of previous fields to find a preferred counterpart for each current field set of pixel data. A prediction error signal is generated for each current field set of pixel data indicative of the difference between it and its preferred counterpart from a previous field. Each prediction error signal is encoded with data indicative of the previous field in which the preferred counterpart can be found. In a preferred embodiment, each set of current field pixel data is compared to a range of similarly situated pixels in each of the previous fields, and the prediction error signal is also encoded with motion vector data indicative of the location of the preferred counterpart in its previous field.