Zigzag掃描

Zigzag掃描代碼 MATLAB版 支持M*N矩陣

即將一個 M * N 的矩陣，依 Zigzag 順序掃描爲 1 * (M*N) 的向量。

代碼如下，僅供參考。

function [vec,vecNum] = zigzagScan(mtr)
% zigzagScan(img) Use zigzag pattern order to scan a matrix.
% [vec, vecNum] = zigzagScan(img) Scan a matrix by using zigzag
% pattern order. The input parameter matrix is a m-by-n matrix. The
% output parameter vec is a 1-by-(m*n) vector that generated by
% zigzag scan. The output parameter vecNum is the length of vector.
% In general, vecNum equals to (m*n).
%
% version: v1.0
% author: tianlan
% time: Dec 16, 2016

% CHECK INPUT ARGUMENTS
if nargin < 1
    error('Not enough input arguments!');
elseif nargin > 1
    error('Too many input arguments!');
end
% Get size of image.
[m,n,t] = size(mtr);
if t ~= 1
    error('The input matrix needs to be m-by-n matrix!');
end

% SCAN A MATRIX BY USING ZIGZAG ORDER.
vec = mtr;
vec = reshape(vec,1,m*n);
% zigzag scan.
x = 1;
y = 1;
vecNum = 0;
vecNum = vecNum + 1;
vec(1,vecNum) = mtr(x,y);
while 1
    % arrive right-up border, needs to change direction.
    if (y+1) <= n && x == 1 %towards right one step.
        y = y + 1;
    elseif (y+1) > n && (x+1) <= m %towards down one step.
        x = x + 1;
    else
        break;
    end
    vecNum = vecNum + 1;
    vec(1,vecNum) = mtr(x,y);
    %judge the scan process is arrived the right-down corner (i.e. mtr(m,n)) or not.
    if x == m && y == n 
        break;
    end
    % scan the matrix towards with left-down direction.
    while (y-1) >= 1 && (x+1) <= m
            y = y - 1;
            x = x + 1;
            vecNum = vecNum + 1;
            vec(1,vecNum) = mtr(x,y);
    end
    % arrive the left-down border, needs to change direction.
    if (x+1) <= m && y == 1% towards down one step.
        x = x + 1;
    elseif (y+1) <= n && x == m %towards right one step.
        y = y + 1;
    else
        break;
    end
    vecNum = vecNum + 1;
    vec(1,vecNum) = mtr(x,y);
    %judge the scan process is arrived the right-down corner (i.e. mtr(m,n)) or not.
    if x == m && y == n 
        break;
    end
    % scan the matrix towards with right-up direction.
    while (x-1) >= 1 && (y+1) <= n
        x = x - 1;
        y = y + 1;
        vecNum = vecNum + 1;
        vec(1,vecNum) = mtr(x,y);
    end
end