错误'使用图像时出错图像CData所需的数字或逻辑矩阵'和'哈哈（第28行）图像（垫）中的错误'

Question

为什么我无法显示10 x 10矩阵的图像？我想创建一个10x10平方的棋盘。 这是我的代码：

tile{6} = imread ('tw.png','png');

tile{5} = imread ('twpw.png','png');

tile{4} = imread ('twpb.png','png');

tile{3} = imread ('tb.png','png');
%this is the black color tile
tile{2} = imread ('tbpw.png','png');
%this is the white color tile
tile{1} = imread('tbpb.png','png');

r = 10;

c = 10;

for i = 1:r

    for j = 1:c

  mat{i,j} = [tile{1}, tile{2}];


    end
end

image(mat)