load('mnist_all.mat');

type = 'train';

savePath = 'G:\data\mnist\train\';

for num = ::

    numStr = num2str(num);

    tempNumPath = strcat(savePath, numStr);

    mkdir(tempNumPath);

    tempNumPath = strcat(tempNumPath,'\');

    tempName = [type, numStr];

    tempFile = eval(tempName);

    [height, width]  = size(tempFile);

    for r = ::height

        tempImg = reshape(tempFile(r,:),,)';

        tempImgPath = strcat(tempNumPath,num2str(r-));

        tempImgPath = strcat(tempImgPath,'.bmp');

        imwrite(tempImg,tempImgPath);

    end

end