| 摘要 |
A method and apparatus for transmitting digital luminance and chrominance television signals utilize unchanged PCM codewords and PCM codewords which have been converted into DPCM codewords. The DPCM codewords each contain the difference between the scan values to which they are allocated and the scan values for the adjacent, unchanged PCM codewords. If the amplitude value of an unchanged PCM codeword is B and if the amplitude values of the adjacent PCM codewords are A and C, inverting registers are employed to invert the amplitude value B in relation to the other amplitude values. Adders then form different codewords with the amplitude values A-B and C-B which are encoded in DPCM coders. At the correct time a parallel-series register converts the unchanged PCM codeword and the newly formed DPCM codewords into a time division multiplex signal. Corresponding reconversion is undertaken at the receiving side. |
