title: Indexing the output points of an LBVQ used for image transform coding.
abstract: A new method for indexing the points of a lattice-based vector quantizer (LBVQ) used to quantize the DCT coefficients of images is presented. With this method, a large number of lattice points can be selected as codewords. As a result, the quality of the compressed data can be very high. The problem is that the large number of points results in a high bit rate. To reduce the bit rate, a shorter representation is assigned to the more frequently used lattice points. These points are grouped and a prefix code is used to index these lattice points. Our method outperforms JPEG, particularly, in the case of images with high frequency components.
authors.affiliation: Department of Electrical and Computer Engineering, Concordia University, Montreal, P.Q., H3G 1M8, Canada.
authors.forename: M
authors.initials: M
authors.lastname: Khataie
authors.forename: M R
authors.initials: MR
authors.lastname: Soleymani