It presents a zerotree coding method for gray images that uses no lists during encoding and decoding
permitting the omission of the lists requirement in Said and Pearlman's Set Partitioning In Hierarchial Trees (SPIHT) algorithm.Without lists
the memory requirement is reduced significantly
and the improved listless zerotree coding method enhances the coding speed by improving the zerotree coding process
and reduces the complexity in the encoding and decoding procedure.Experimental results show that the improved LZC codec increases the ratio of compression ratio at the same PSNR
so improved LZC method is an efficient method for image coding.