METHOD AND APPARATUS FOR IMAGE DATA COMPRESSION USING COMBINED LUMINANCE/CHROMINANCE CODING

A technique is provided for a color imaging system having a luminance component and two color difference (chrominance) components, which allots more space in the compressed data stream to the signal component of greater information content or complexity; that is, which combines the encoding of the components of the data representing a common portion of an image in response to the actual needs of the component, prior to encoding the combined data. To this end, the calculation of the quantizing factors considers the combined information content of both the luminance and chrominance components for the same image location. Thus, low chrominance complexity allows the transmission of more of the luminance information, and vice versa. The system also provides for predetermining the relative complexity of the signal components to thus pre-allot the amount of space for each signal component in the compressed data stream in proportion to its measured complexity.