18、变换域图像压缩中的块效应处理

变换域图像压缩中的块效应处理

1. 之字形扫描函数

在图像压缩处理中，之字形扫描是一个重要的操作。下面是一个实现之字形扫描的函数：

function y = ZigZag(x)
% y = ZigZag(x)
% returns the zigzag scan addresses of an 8 x 8 array
y(1) = x(1,1);y(2) = x(1,2);y(3) = x(2,1);y(4) = x(3,1);
y(5) = x(2,2);y(6) = x(1,3);y(7) = x(1,4);y(8) = x(2,3);
y(9) = x(3,2);y(10) = x(4,1);y(11) = x(5,1);y(12) = x(4,2);
y(13) = x(3,3);y(14) = x(2,4);y(15) = x(1,5);y(16) = x(1,6);
y(17) = x(2,5);y(18) = x(3,4);y(19) = x(4,3);y(20) = x(5,2);
y(21) = x(6,1);y(22) = x(7,1);y(23) = x(6,2);y(24) = x(5,3);
y(25) = x(4,4);y(26) = x(3,5);y(27) = x(2,6);y(28) = x(1,7);
y(29) = x(1,8);y(30) = x(2,7);y(31) = x(3,6);y(32) = x(4,5);
y(33) = x(5,4);y(34) = x(6,3);y(35) = x(7,2);y(36) = x(8,1);
y(37) = x(8,2);y(38) = x(7,3);y(