SYSTEM AND METHOD HAVING TRANSPARENT COMPOSITE MODEL FOR TRANSFORM COEFFICIENTS

摘要

To better handle the flat tail phenomenon commonly seen in transform coefficients such as DCT coefficients, a system and method having a model dubbed a transparent composite model (TCM) are described. Given a sequence of transform coefficients, a TCM first separates the tail of the sequence from the main body of the sequence. A first distribution such as a uniform, truncated Laplacian, or truncated geometric distribution can be used to model transform coefficients in the flat tail while at least one parametric distribution (e.g. truncated Laplacian, generalized Gaussian (GG), and geometric distributions) can be used to model data in the main body. A plurality of boundary values can be used to bound a plurality of distribution models. The plurality of boundary values and other parameters of the TCM can be estimated via maximum likelihood (ML) estimation or greedy estimation.

主权项

1. A method for modelling a set of transform coefficients, the method being performed by a device and comprising:
determining at least one boundary coefficient value; determining one or more parameters for a first distribution model for transform coefficients of the set the magnitudes of which are greater than one of the boundary coefficient values; determining parameters for at least one further distribution model for transform coefficients of the set the magnitudes of which are less than the one of the boundary coefficient values; and performing a device operation on at least part of a composite distribution model which is a composite of the first distribution model and the at least one further distribution model having the respective determined parameters.