Fast codebook search algorithms for VQ of wavelet images

Two fast codebook search algorithms are proposed for vector quantization (V Q) encoding in wavelet/VQ coding schemes, These algorithms complement the p artial distance elimination (PDE) algorithm by satisfying the premature exi t condition in an early stage, The algorithms are especially appropriate fo r high vector dimension. Furthermore, any triangular inequality elimination (TIE) methods which reduce the search spade can be integrated with our met hods to further save the encoding time, The computational complexity is red uced by exploiting the property of the wavelet domain in which large coeffi cients rarely exist. Experimental results confirm the effectiveness of the proposed algorithms.