Abstract: A display backlight is described which produces white light of a specified color point and from light sources of different chromaticities and in which the red wavelengths emitted by the light sources are emitted by light sources of two or more chromaticities from the group of at least three different chromaticities and arranged to be driven with the result that visible, red-colored artifacts are reduced at boundaries of high image contrast when the backlight is coupled to further display components and used for display of a grey scale image. The invention allows production of a display with an adjustable white color point but which also does not suffer from distracting red, fringe-like artefacts reported by users of displays comprising white backlights produced from red, green and blue light sources. A display incorporating the backlight is also described.

Abstract: A two-dimensional enhancement function (HEF; VEF) determines a peaking factor (CX; CY) for an input signal (L(m,n)) based on the output signals of both a first edge detector (HHP; VHP) and a second edge detector (HBP; VBP) which both operate in the same first spatial direction. In this manner, all different kind of borders which may occur in the input signal (L(m,n)) in the first spatial direction are distinguished. The two-dimensional enhancement function (HEF; VEF) allocates values which determine the amount of peaking to the different combinations of the output signals (ZX, DX; ZY, DY). It is possible to select the values allocated by the two-dimensional enhancement function (HEF; VEF) different for different kind of borders to obtain the desired amount of peaking fitting each kind of border best.