Technique for reducing transmission error propagation in an adaptively predicted DPCM video encoder
Method and apparatus for efficiently communicating image sequences
Method and apparatus for efficiently communicating image sequence having improved motion compensation
Method and apparatus employing adaptive filtering for efficiently communicating image sequences
Digital video encoder
Television signal arrangement where selected signals are encoded digitally
High definition television arrangement employing motion compensated prediction error signals
High definition television arrangement with signal selections adapted to the available transmission capacity Patent #: 5063444
ApplicationNo. 625522 filed on 12/11/1990
US Classes:375/240.12, Predictive348/472, Pulse code modulation375/245, Quantizer or inverse quantizer375/246Length coding
ExaminersPrimary: Peng, John K.
Attorney, Agent or Firm
International ClassesH04N 007/12
AbstractIn a differential PCM encoder, the problem of error perpetuation is solved by leaking a changing, rather than a fixed, fraction of the input signal to the differential PCM. The fraction leaked is sensitive to the characteristics of the signal. In one embodiment the fraction leaked is fixed for a frame in accordance with a chosen characteristic of the frame signal. In another embodiment, the fraction leaked is set in accordance with one function when a chosen characteristic of the frame signal exceeds a given level, and follows another function when the chosen characteristic does not exceed the chosen level. In a still another embodiment, the fraction leaked is set to one of two levels, based on a chosen characteristic of the frame signal.