Since ISZW used successive integer squares as quantization thresholds, it shortened the distance between two consecutive thresholds, but increased coding times, thus reduced coding speed.

• 但是，由于ISZW使用连续的整数平方作为量化阈值，缩短了相邻阈值间的距离，却增加了编码的次数，降低了编码速度。