“…In the paper, the modified coding tree assignment scheme (MCTAS) is presented to improve the coding efficiency of the image VQ scheme and reduce time complexity of the CTAS‐ISOC [29] technique by exploiting the correlations of the neighbouring blocks in the previously constructed index table. Experimental simulations show that the proposed scheme reaches better performance in bit rate than other popular existing lossless index compression methods, such as SOC [20], MSOC [21], LCIC [22], ICS [25], AICS [26], ISAIAL [27], modified ISAIAL [28] and CTAS‐ISOC [29].…”