title: Trellis-based R-D optimal quantization in H.263+.
abstract: We describe a trellis-based algorithm which enables R-D optimum quantization decisions in the H.263+ video coding standard. The algorithm allows the quantization decisions for all coefficients in a block to be made jointly, and experiments conducted using H.263+ for video coding rates of 40-50 kbps show an average improvement of 3.5% in bitrate relative to implementations which follow the International Telecommunications Union (ITU) Test Model specifications in making quantization decisions.
authors.forename: J
authors.initials: J
authors.lastname: Wen
authors.forename: M
authors.initials: M
authors.lastname: Luttrell
authors.forename: J
authors.initials: J
authors.lastname: Villasenor