Method and apparatus for scaling parameter coding for inter-component residual prediction

A method of inter-component residual prediction for a video decoder system, the method comprising:

• receiving coded data of a first color block and a second color block corresponding to a first color component and a second color component of input video data respectively from a bitstream;
• generating reconstructed first color prediction residual from the coded data;
• generating reconstructed first inter-color predicted residual from the coded data;
• determining a first scaling parameter by parsing one or more syntax elements from the bitstream and performing a first context-based decoding on said one or more syntax elements by using separate context models for each bin of absolute values of the first scaling parameter, wherein a first number of context models used by the first context-based decoding is equal to a number of bins of a longest binary code for the absolute values of the first scaling parameter;
• generating reconstructed first inter-color residual predictor by scaling the first color prediction residual with the first scaling parameter;
• generating reconstructed second color prediction residual based on the reconstructed first inter-color predicted residual and the reconstructed first inter-color residual predictor;
• generating reconstructed first color block by applying first Inter/Intra or inter-view decoding to the reconstructed first color prediction residual;
• and
• generating reconstructed second color block by applying second Inter/Intra or inter-view decoding to the reconstructed second color prediction residual.