function x = dezz(z)% function x = dezz(z)% undo zz.m (<z> is a vector, <x> a 8x8 block)zi=[1   2   6   7  15  16  28  29   3   5   8  14  17  27  30  43   4   9  13  18  26  31  42  44  10  12  19  25  32  41  45  54  11  20  24  33  40  46  53  55  21  23  34  39  47  52  56  61  22  35  38  48  51  57  60  62  36  37  49  50  58  59  63  64];% work on columnszi = zi(:);x = reshape(z(zi),8,8);