Improved multi-resolution image processing

摘要

An improved image coder is proposed for efficiently encoding an image signal. A resolution reducer (305) derives a lower resolution signal (S3) from an input signal (S2). An interpolator (355) produces a predicted signal (IXD3) from the lower resolution signal (S3), and an upper resolution predictor (250) delivers a difference signal (DBD2) from said input signal (S2) and from said predicted signal (IXD3). According to the invention, the difference signal (DBD2) is further transformed into a modified difference signal, in which samples are discarded according to a scheme, such that the difference signal (DBD2) is substantially recoverable from the modified difference signal. The input signal may thus be represented by the modified difference signal which much smaller and may be used to reconstruct the input signal.
A decoder is also proposed as well as corresponding methods of encoding and decoding image signals.