A system and method for generating a multi-tone representation of a digital image by applying a plurality of functions of luma to the digital image. The functions of luma comprise at least a first function and a second function, where each function has a value for each luma value in a range of luma values....http://www.google.com/patents/US6933948?utm_source=gb-gplus-sharePatent US6933948 - Multi-tone representation of a digital image on a digital nonlinear editing system
