Patent ID: 11924433
Assignee: CANON KABUSHIKI KAISHA
Field: Audio-visual technology (Electrical engineering)
Classification: CPC H | IPC H

Claim 8:
9. A method of decoding one or more images from a bitstream by deriving a linear model for obtaining a chroma sample value of a chroma block of a target area from an associated luma sample value of a luma block in the same frame, wherein the method comprises:
determining two pairs of values for determining the linear model, each of the two pairs of values being defined by two variables, a first variable of said two variables corresponding to a luma sample value a second variable of said two variables corresponding to a chroma sample value,
wherein the two pairs of values for determining the linear model are determined based on at least down-sampled luma sample values in the neighbourhood of the target area;
wherein each value in said two pairs of values for determining the linear model is determined by averaging two values based on the sample values in the neighbourhood; and
determining parameters of the linear model by calculating a difference between the luma sample values of the two pairs of values for determining the linear model and a difference between the chroma sample values of the two pairs of values for determining the linear model.