| 摘要 |
<p>PURPOSE:To suppress a quantization error, and to prevent an adverse influence such as waveform distortion and overload noise, etc., by transmitting through a buffer memory a data which has quantized directly an input data signal, when a prediction error in case of predictive coding becomes large. CONSTITUTION:A sample data in a block at the time when a suitable prescribed number of picture elements of an NTSC video signal formed a block is inputted, and an Hadamard conversion is performed by an Hadamard converting circuit 2. A difference to an output of a prediction device 14 is taken by a subtracter 11, and when the difference is large, an overload detecting circuit 15 detects it, a changeover switch 17 is brought to a switching control to a terminal (b) side, and instead of the output of a non-linear quantizer 12 which has executed a predictive coding processing (differential data), an output which has brought a signal which does not go to a difference, to non-linear quantization 16 is selected, and sent to a buffer memory 3. Also, this output is sent to the prediction device 14 through a changeover switch 18, and discontinuity of a prediction data is prevented.</p> |
