Concealment techniques for data-reduced HDTV recording

摘要

Most of all data-reduced HD-VCRs use powerful error protection schemes in order to prevent error propagation. Under normal conditions these schemes are able to correct all errors from magnetic tape channel. However, under bad conditions some uncorrected errors may be left. Therefore, it must be possible to conceal erroneous DCT blocks in order to avoid visible degradations in this worst-case situation. In this context four different concealment techniques (spatial, temporal, motion-adaptive and motion-compensated concealment) are discussed and compared with respect to their efficiency. The results of subjective tests and the discussion of some system aspects show that the motion-adaptive approach is the most suitable one for the underlying application.