A method for processing data for display on a screen involves encoding, using a first colour space, a first portion of image data intended to be displayed on a first area of the screen and encoding, using a second colour space, a second portion of image data intended to be displayed on a second area of the screen. The encoded first and second portions of the image data are compressed, and transmitted over a link for display on the screen. By using different colour spaces to encode image data that is displayed in different parts of a screen, differences in a user's vision and/or aberrations caused by display equipment may be accounted for and so provide an improved user experience. Using different colour spaces for different screen areas may also reduce the amount of data that needs to be transmitted, for example by encoding image data more effectively and/or allowing more efficient compression of data.