Point-symmetric signal extension for tile-based image compression

A new method called point-symmetric signal extension is developed for finite-length signal sub-band decomposition providing perfect reconstruction. The proposed approach is considered as an alternative to the well-known symmetric signal extension in dealing with the boundary artifacts that manifest when tiles of images are lossy compressed. The new solution greatly reduces discontinuity between the adjacent tiles without requiring any post processing technique or additional information from the neighbouring tiles. A memory efficient implementation based upon the point-symmetric extension has been accepted into the Verification Model of the emerging JPEG2000 image compression standard.