In some cases, a codebook implementation can be also used to entropy code the discrete value in the same step by generating a prefix coded variable-length encoded value as its output.
In [[data compression]], '''vector [[quantization]]''' is a [[quantization]] technique (usuallyoften used in [[lossy data compression|lossy]]) in which the basic idea is to code values from a multidimensional [[vector space]] into values from a discrete [[subspace]] of lower dimension. The lower-space vector requires less storage space and the data is thus compressed. The transformation into the subspace is usually achieved through [[projection]], or by using a [[codebook]]. In some cases, a codebook implementation can be also used to [[entropy code]] the discrete value in the same step by generating a [[prefix code]]d variable-length encoded value as its output.
