“…Although the 3eparable model of (A-i) has been used for data compression [67,68,87], for reasons discussed in Appendix A, nonseparable models are preferable in many cases. Therefore,the nonseparable models described by (A-2), (A-3), (A-4), (A-5) and others have been used for data compression [49,53,67,68,75] with better results than the separable model. The most commonly used transforms in these studies are the Cosine and the Hadamard.…”