Method and apparatus for the improvement of image quality in darker areas of a digital display

摘要

Targeted insertion of noise signals create additional brightness intermediate stages in dark areas, using noise generator before gamma corrector or using dither circuit between gamma corrector and display. Video signals from color decoder (1) fed to overlay circuit (5) have noise signal of amplitude probability distribution same as video signal, overlaid on them. Output signal (k1) is gamma corrected by 8-bit quantizer (2) thus providing dithered signal (k2) to display (3). Video signals from color decoder (1) are fed to overlay circuit (5), and noise signal of amplitude probability distribution same as video signal, is overlaid on video signal. Output signal (k1) is gamma corrected by conventional 8-bit quantizer (2) thus providing signal dithered by noise. Output (k2) is fed to display (3). Alternatively video signals from color decoder are gamma corrected (2), made non-linear and then fed to dither circuit and to display. Independent claim for device to improve image quality of dark areas of digital image display.