Nonlinear, in-the-loop, denoising filter for quantization noise removal for hybrid video compression

A decoder comprising:

• a transform decoder to generate a decoded differential frame;
• an adder to create a reconstructed frame in response to the decoded differential frame and a first prediction;
• a denoising filter to filter the reconstructed frame by creating expectations and performing denoising operations based on the expectations;
• and
• a prediction module to generate predictions, including the first prediction, based on previously decoded frames.

The video decoding process further comprising:

• obtaining a decoded frame and other available information;
• obtaining a set of coefficients by applying a transform to the decoded frame;
• setting a set of image elements equal to elements of the decoded frame;
• determining coefficient parameters and a mask function based on compression parameters;
• computing a conditional expectation of a filtered coefficient for each coefficient in a set of coefficients obtained by applying the transform to the new coded frame, wherein the conditional expectation is obtained by applying a denoising rule using the value of the coefficient in the set of coefficients and the conditional expectation of the filtered coefficient;
• and
• obtaining a filtered frame by applying a mask function to the result of the inverse of the transform applied to the set of filtered coefficients.