An improved embedded zerotree wavelet image coding algorithm is proposed in this paper. It is an improved vision of Shaprio's EZW algorithm. First

a single list scheme is used in successive-approximation Quantization(SAQ)

dispensing with double dynamic list of EZW algorithm. The single list make the scan process more simple and faster

and lead to better rate-distortion characteristic. Second

a fast algorithm based on spatial orientation tree recursive scan for the zerotree coding is designed. The zerotree symbols of one quantization layer can be calculated with only one access per coefficient

solving the rescaning problem completely. At last

a new Markov model based on quantization symbol field relativity for adaptive arithmetic coding algorithm is used

for higher compression efficient. Experimental results show that it peroforms better than the EZW algorithm in coding efficiency

maintains the fine-granularity scalability.