Two-layer coding for videotelephone

B. Sankur, R. A. van Schijndel, J. C.A. van der Lubbe

Research output: Contribution to journalArticleAcademicpeer-review


Design of a two-layer coding scheme is considered under the constraint that the first layer running at 64 kbit/s is to perform the normal H.261 functions. The second layer is recruited optionally to enhanced the image quality and/or to increase the frame rate. In the chosen scheme, the second laeyr processes the difference between the original signal and the reconstruction of the first layer, by a combination of DCT and pixel correction techniques. While SNR improvements achieved were of the order of 1 dB, subjective tests indicated a much stronger preference for the two-layer codec.

Original languageEnglish
Pages (from-to)295-303
Number of pages9
JournalSignal Processing: Image Communication
Issue number4
Publication statusPublished - 1 Jan 1993
Externally publishedYes


  • Two-layer coding
  • videophone

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