An analogue-to-digital converter 2 for video signals has a sensitivity (reference) input 4 controlled by a controller 10 in response to the converter's digital output so as to maintain the grey level with a predetermined range. Preferably the controller employs an irregular subsampling of the digital values, and responds differently to extreme and mid-range samples. A scale factor may be forwarded to a digital-to-analogue converter for reconversion.
申请公布号
DE3669250(D1)
申请公布日期
1990.04.05
申请号
DE19863669250
申请日期
1986.10.09
申请人
BRITISH TELECOMMUNICATIONS P.L.C., LONDON, GB
发明人
AZAM, MOHAMMAD SHABIR, KESGRAVE IPSWICH IP5 7IB, GB;CARR, MICHAEL DOUGLAS, IPSWICH IP10 0RL, GB