imread slower with huge tif files

Images1=zeros(128,128,20000);
Images2=zeros(200,200,20000);

len=20000;

for k=1:len
    k
    Images1(:,:,k) =   double(imread(path1,k));
    Images2(:,:,k) =   double(imread(path2,k));
    
end

The for loop becomes slower when k is high, why? and how can I prevent it?

The files that I am reading are .tif files

Answer 1

[Walter Roberson]

Use the Tiff() class to work more directly with the tiff structure.