Contrast and brightness control whereby both are based on the detected difference between a fixed black level in the video signal and the black peak value

Abstract

Abstract A circuit arrangement for processing an input video signal (V) is described, which video signal has a fixed black level (SP), a given white peak value (WW) as well as a black peak value (SW) dependent on the picture contents (during tb), in which a correct display of the blackest and brightest parts of the picture contents of the video signal (V) is rendered possible without many components and without interference. To this end the circuit arrangement includes a detection device (1) for detecting the difference between the fixed black level (SP) in the video signal (V) and the black peak value (SW) detected in the picture contents (during tb) of the video signal (V), a level shifting device (6) for forming a black value-corrected video signal (V') by shifting the level of the picture contents of the video signal (V) by the detected difference towards the black level (SP), and an amplitude steering device (8) for forming an amplitude-corrected video signal (V") by correcting the amplitude of the picture contents (during tb) of the black value-corrected video signal (V') in accordance with an amplitude steering signal obtained from the detected difference such that the amplitude-corrected video signal (V") has the same given white peak value (WW) as the input video signal (V).

Inventors

• 👤 Hartmut Harlos
• 👤 Klaus Kroner
• 👤 Matthias Peters
• 👤 Jorg Wolber

Bibliographic Details