IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS FOR VIDEO TECHNOLOGY, VOL. 12, NO. 10, OCTOBER 2002
Novel Sequential Error-Concealment Techniques
Using Orientation Adaptive Interpolation
Xin Li, Member, IEEE, and Michael T. Orchard, Fellow, IEEE
Abstract—This paper introduces a new framework for error
concealment in block-based image coding systems: sequential re-
covery. Unlike previous approaches that simultaneously recover
the pixels inside a missing block, we propose to recover them in
a sequential fashion such that the previously-recovered pixels can
be used in the recovery process afterwards. The principal advan-
tage of the sequential approach is the improved capability of re-
covering important image features brought by the reduction in the
complexity of statistical modeling, i.e., from blockwise to pixelwise.
Under the framework of sequential recovery, we present an ori-
entation adaptive interpolation scheme derived from the pixelwise
statistical model. We also investigate the problem of error propaga-
tion with sequential recovery and propose a linear merge strategy
to alleviate it. Extensive experiment results are used to demon-
strate the improvement of the proposed sequential error-conceal-
ment technique over previous techniques in the literature.
Index Terms—Error concealment, error propagation, linear
merge, orientation adaptive interpolation, sequential recovery.
B LOCK-BASED image coding systems have been exten-
sively studied for efficient transmission of visual signals.
Most existing image and video compression standards such as
JPEG  and MPEG  structure an image into nonoverlapped
blocks and process them separately. When the encoded bit
stream goes through a time-varying channel such as wireless
or ATM network, it is vulnerable to the channel impairment.
In the block-based image coding system, the loss of one single
bit often results in the loss of the whole block, which seriously
affects the visual quality of decoded images at the receiver. The