关于Matlab图像分析的代码

[键盘国治理专家]

function [C, label, J] = kmeans(I, k)   %传了一张图片进来，按4进行聚类
[m, n, p] = size(I);
X = reshape(double(I), m*n, p);
rng('default');
C = X(randperm(m*n, k), :);
J_prev = inf; iter = 0; J = []; tol = 1e-2;
while true;
    iter = iter + 1;
    dist = sum(X.^2, 2)*ones(1, k) + (sum(C.^2, 2)*ones(1, m*n))' - 2*X*C';
    [~, label] = min(dist, [], 2) ;
    for i = 1:k;
       C(i, :) = mean(X(label == i , :));
    end
    J_cur = sum(sum((X - C(label, :)).^2, 2));
    J = [J, J_cur];
    display(sprintf('#iteration: %03d, objective fcn: %f', iter, J_cur));
    if norm(J_cur-J_prev, 'fro') < tol;
        break;
    end
    J_prev = J_cur;
end

此处，I是一张图片，从size(I)就开始完全看不懂了，希望了解这些函数功能的能指点一下，查Matlab自带的文档并没有查到相应的，所以本地解决没办法，希望大家能够解答。