| 摘要 |
<p>PURPOSE:To prevent the quantizing noise from being prominent without increasing the number of the bits of A/D and D/A conversions by making the quantizing step width at the dark part side of an analog video signal larger than the quantizing step width at the bright part side. CONSTITUTION:The title device is provided with an A/D converter to execute the digital conversion of an analog video signal, a digital signal processing part to process the obtained digital data and a D/A converter to correspond to the analog-digital converting characteristic of the A/D converter and execute the digital-analog conversion of the processed digital data. The quantizing step width at the dark part side of an analog video signal is set so as to be made larger than the quantizing step width at the bright part side of the analog video signal. Consequently, out of an analog video signal, at a dark part side Q2 with a prominent noise, the quantization is executed by a thin step width q2 and at a bright part side Q1 with an inconspicuous noise, the quantization is reversely executed by a large step width q1. Thus, without increasing the number of the bits of A/D and D/A conversions, the quantizing noise is decreased.</p> |
