error in finding compression ratio

i have a code

    out=imcompr('dock.jpg',20,'output_image01.bmp');
    k=imfinfo('output_image01.bmp');
    ib=k.Width*k.Height*k.BitDepth/8;
    cb=k.FileSize;
    cr=ib/cb

if i change the values of 20 as 50 ,200,2000,i get same value please help

[Jan]

You forgot to ask a question.