Fast VQ encoding algorithms using angular constraint

In this paper, we propose two fast encoding algorithms for vector quantization. The first algorithm uses three significant features of a vector, that is , the norm, its projection angle to a reference line and the mean, to reduce the search area and accelerate the search process. The second algorithm has feature of using a suitable hyperplane to partition the codebook and image data. These algorithms allow significant acceleration in the encoding process. Experimental results are presented on image block data. These results confirm the effectiveness of our proposed algorithms.