Abstract

Abstruct-A new expression for the output moments of weighted mcdian filtered data is derived in this paper. The noise attenuation capability of a weighted median filter can now be assessed using the L-vector and AI-vector parameters in the new expression.The second major contribution of the paper is the development of a new optimality theory for weighted median filters. This theory is based on the new expression for the output moments, and combines the noise attenuation and some structural constraints on the filter's behavior.In certain special cases, the optimal weighted median filter can be obtained by merely solving a set of linear inequalities. This leads in some cases to closed form solutions for optimal weighted median filters. Some applications of the theory developed in this paper, in 1-D signal processing and image processing are discussed.Throughout the analysis, some striking similarities are pointed out between linear FIR filters and weighted median filters.

Abstract

No abstract

This paper presents the error concealment (EC) feature implemented by the authors in the test model of the draft ITU-T video coding standard H.26L. The selected EC algorithms are based on weighted pixel value averaging for INTRA pictures and boundary-matching-based motion vector recovery for INTER pictures. The specific concealment strategy and some special methods, including handling of B-pictures, multiple reference frames and entire frame losses, are described. Both subjective and objective results are given based on simulations under Intemet conditions. The feature was adopted and is now included in the latest H.26L reference software TML-9.0.