Abstract: A initial codebook algorithm that can distribute uniformly in training set and combine with lossless compress method is proposed.To overcome disadvantages of existing initial codebook algorithms, the initial codebook with uniform distribution is produced,and iteratively produce final codebook using Linde-Buzo-Gray(LBG). Experimented results show that new method can get better visual effect.

Key words: ordered dither halftone, vector quantization, initial codebook, visual effect

摘要： 结合有序抖动半调图像特性，针对原有矢量量化初始码书算法存在非典型码字、运算量大和空间分布不均匀等欠缺，提出一种能在训练集中均匀分布的初始码书生成方法，应用到LBG算法中，并结合无损压缩方法，进行二次压缩。实验表明，本方法压缩比高、实现简单，且解码后图像视觉效果得到明显改善。

关键词: 有序抖动, 矢量量化, 初始码书, 视觉效果