Method and apparatus of inheriting cross-component models with cross-component information propagation in video coding system

Abstract

Methods and apparatus for video coding using inherited cross-component information propagation or innovative default cross-component candidate. According to the first method, an inherited cross-component prediction candidate is derived by inheriting one or more cross-component model parameters associated with an inheriting neighbouring block. The inherited cross-component prediction candidate is stored and used in a reconstruction process of a neighbouring block in a subsequent picture. According to the second method, a default cross-component prediction candidate is generated by using neighbouring reconstructed first-colour samples and second-colour samples of the current block to derive a cross-component model for the default cross-component prediction candidate, or by using partial model parameters or modifying model parameters associated with an earlier candidate to derive the cross-component model for the default cross-component prediction candidate.