Abstract: A method and apparatus for generating gamma corrected analogue voltages uses a first ladder resistor arrangement (34) to provides a first set of analogue voltage levels. A second set of voltages (x) is selected by programming a multiplexer arrangement (36) at the output of the first ladder resistor arrangement (34). A second ladder resistor arrangement (32) is used to provide a third set of analogue voltage levels which are at intermediate voltage levels between voltage levels of the second set (x). The output (g) is the buffered voltages of the second and third sets. This arrangement enables the amount of data that needs to be programmed to be reduced to a minimum required to implement the desired differences between the gamma functions. The voltages in the second set do not need to be evenly spaced, and more variability in the shape of the gamma curve can be provided where it is needed to best reflect different characteristics of possible displays to be driven.

Abstract: A method of storing colour pixel data provides the pixel data in YUV form with a first number of bits per colour component. The number of bits of the U and V components of each pixel data element are reduced to provide modified YUV data, wherein the reduction in the number of bits is carried out for each pixel without reference to other pixel data. Data are stored in a form which retains independence between each pixel. This enables processing of the data in the memory in a simple manner, for example enabling individual pixel data to be changed, and simplifying image processing such as rotation and mirroring. The luminance information Y is preserved, and only the chrominance information is compressed. This can enable high quality to be maintained in greyscale images and in text images, whilst also providing a loss in colour resolution to natural colour images which may not be perceived by a user.