1. A method for improving the perceived visual quality of images for instance displayed on a colour television screen, the method comprising: provision of an input video signal (Y′, U, V) ( 6 ); carrying out a histogram processing ( 13 ) on said incoming video signal ( 6 ), whereby a luminance transfer function T (k) is obtained and based on said luminance transfer function T (k) calculating a global chrominance gain g c ( 16 ); for individual pixels of the image carrying out a chrominance processing ( 14 ) that associates a local gain g(U p ,V p ) for each individual pixel having the colour components (U p , V p ); provision of an output video signal (Y′, U, V) OUT2 ( 18 ) for individual pixels wherein: the luminance component Y′ OUT2 is determined by said luminance transfer function T (k); the first chrominance component U OUT2 is given by the expression: 
 U OUT2 =g c g ( U p ,V p ) U p ; and the second chrominance component V OUT2 is given by the expression: 
 V OUT2 =g c g ( U p ,V p ) V p ; whereby the chrominance components of the individual pixels of the image are modified by a global gain factor g c relating to the characteristics of the entire image and a local gain factor g relating to the individual pixels.