一种新的基于子空间三角不等式快速搜索的参考矢量选择方法

A New Method of Selecting Reference Vector for Fast Search Algorithm Using Triangle Inequality in Subspace

提出了一种新的参考矢量选择方法.编码前,首先计算所有码字的哈德码变换,按照第一维系数的大小对码字进行升序排序,将排序后的码字平均分为四段,选择每一段中间位置的码字作为该段的参考矢量,从而增加了子空间三角不等式删除准则的删除能力,有效减小了搜索空间,加快了搜索速度.仿真实验表明,对不同复杂程度的测试图像,算法均快于其他搜索算法.

A new method of selecting reference vector for fast search algorithm using inequality in subspace proposed by Cui et al is proposed.Before the searching process,all codewords are transformed in Hadamard-transformed and sorted in an ascending order according to their first dimensions.The sorted codewords in the codebook are divided into four groups equally and the middle codeword of each group is selected as the reference vector.The method of selecting reference vector in this paper can increase the ability of fast search algorithm using inequality in subspace in rejecting the unlikely codewords and reduce the searching space and speed up the searching time.The experimental results show that the proposed method has a better performance than other fast search algorithm in searching time for different test images.