matlab 图像分块及恢复

1. block_divide

% 返回的块向量构成的矩阵，其维度信息为 K^2 * N，每一列由块构成的列向量function P = block_divide(I, K)    r = size(I, 1)/K;    c = size(I, 2)/K;    P = zeros(K^2, r*c);    f = @(A) A(:);    for i = 1:r,        for j = 1:c,            P(:, (i-1)*c+j) = f(I(K*(i-1)+1:K*i, K*(j-1)+1:K*j));        end    end end

2. re_divide

% col: 原始图像矩阵的行数function I = re_divide(P, col, K)    N = size(P, 2);    m = floor(sqrt(N));    b44s = [];    for i = 1:N,        b44s = [b44s, reshape(P(:, i), K, K)];    end    I = [];    for k = 1:m,        I = [I; b44s(:, (k-1)*col+1:k*col)];    endend