Patent ID: 7561208

Claim:
A method of using a decoder to blend a first object with a second object, thereby resulting in a blended object, each object comprising chrominance and luminance components, a chrominance value being associated with a set of at least two luminance values, wherein said method comprises: using the decoder to generate the luminance component of the blended object from the corresponding luminance components of the first object and the second object, and from a first composition function, the first composition function based upon at least a transparency component Nalpha y of the luminance component of the first object; and using the decoder to generate the chrominance component of the blended object from the corresponding chrominance components of the first object and the second object, and from a second composition function, the second composition function depending on a set of associated values of the first composition function and based upon at least a transparency component Nalpha uv of the chrominance component of the first object.