The coefficients above segmentation threshold Th were quantized by integer square threshold for shortening the distance between threshold and threshold.An improved binary SPECK coding framework was adopted for these coefficients above threshold Th.The coefficients below Th were quantized by integer powers of two.Finally.binary arithmetic coding without multiplication was adopted for every threshold plane.Compared with embedded zerotree wavelet(EZW),SPIHT and SPECK,the experiment results show that ETSC algorithm has low computational complexity,and increases the encoding efficiency of IWT at low bit rates.Additionally,the new algorithm supports both lossless and lossy decoding using a single bitstream.