US Patent 7561208 Method and decoder for composing a scene

The present invention relates to a method for composing a scene containing a plurality of objects, an object comprising chrominance and luminance components, a chrominance value being associated with a set of at least two luminance values, wherein said method comprises a step of blending a first object with a second object resulting in a blended object, said step comprising the sub-steps of:—generating a luminance component of the blended object from the corresponding luminance components of the first and second objects and from a first composition function, and—generating a chrominance component of the blended object from the corresponding chrominance components of the first and second object and from a second composition function, the second composition function depending on a set of associated values of the first composition function.