Angličtina
Transmission errors in JPEG2000 can be grouped into three main classes,depending on the affected area:LL,high frequencies at the lower decomposition levels, and high frequencies at the higher decomposition levels. The first type of errors are the most annoying but can be concealed exploiting the signal spatially the second type of errors are less annoying but more difficult to concealed , the third of errors are often imperceptible.This book is to address the problem of concealing the errors when high bit-plans are damaged by proposing a new approach based on the theory of projections onto convex sets.Accordingly the error effects are masked by interactively applying two procedures:low pass (LP)filtering in the spatial domain and restoration of uncorrupted wavelet coefficients in the transform domain. It has been observed that a uniform LP filtering brought to some undesired side effects that negatively compensated the advantages.This problem has been overcome by applying an adaptive solution,which exploits an edge map to choose the optimal filter mask size.Simulation results demonstrated the efficiency of the proposed method.
