| 摘要 |
<p>PURPOSE:To prevent deterioration of a picture with simple constitution by treating an interframe encoded signal of a TV signal with a small two-dimensional block and preparing a code for a pattern of higher frequency of occurrence among a group of patterns that occur at statistically high frequency, to select an error signal or an encoded signal. CONSTITUTION:The TV signal from an input terminal 1 is converted into PCM code by an A/D converter 2, supplied to a TDM scan converter circuit 3, and is separated into brightness and chromaticity signals. After the said conversion, the signals are scan-converted for each scanning line and are supplied to a frame encoder 4. The output from the encoder 4 is converted to a two-dimensional signal by the block circuit 11 of an adaptive variable length encoding circuit 5. The block pattern of higher frequency of occurrence is stored beforehand in its storage device 16 of the circuit 5, and a pattern comparator circuit 15 compares the outputs from the circuits 16 and 11. The output from the circuit 15 and that from a exclusive variable length encoding circuit 13 are selectively converted to a variable length code and is outputted. The output from an encoder 1 is used in the circuit 5. Consequently, the picture is prevented from deteriorating with a circuitry of simpler constitution.</p> |
