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嵌入式零树小波编码算法(EZW)在扫描过程中为了判断小波系数是零树根还是孤零,需要对系数进行重复扫描,这样不仅浪费时间,而且会产生大量冗余的符号流。针对EZW算法存在的不足,提出了一种改进的EZW算法,通过增加2个标识符,来避免连续出现零树根,对扫描产生的符号流采用哈夫曼编码。实验表明,改进型的算法,减少了扫描时间,提高了压缩比和编码效率。
Embedded Zerotree Wavelet Coding Algorithm (EZW) In order to determine whether the wavelet coefficients are zerotree or solitary in the scanning process, the coefficients need to be repeatedly scanned. This not only wastes time, but also produces a lot of redundant symbol streams. Aiming at the deficiency of EZW algorithm, an improved EZW algorithm is proposed. By adding two identifiers, zero roots are avoided continuously and Huffman coding is used for the symbol stream generated by scanning. Experiments show that the improved algorithm reduces the scanning time and improves the compression ratio and coding efficiency.