ZigZag Scan any N*N Matrix (bloc of image)

ZigZagscan.m Transform an matrix to a vector using Zig Zag Scan.

ZigZagscan Transform an matrix to a vector using Zig Zag Scan.
%
% VECT = ZIGZAGSCAN(MATRIX) reorganize the input Matrix and output it as a vector.
%
% Example:
% X=[1 2 3
% 4 5 6
% 7 8 9]
%
% X =
% 1 2 3
% 4 5 6
% 7 8 9
%
% ZigZagscan(X)=
% 1 2 4 7 5 3 6 8 9