Loader image not showing up when canvas rotating and resizing operation is going on selected file

Loader image not showing up when canvas rotating and resizing operation is
going on selected file

I have created sample code here http://jsfiddle.net/kamlesh_bhure/YpejU/
where i am rotating image and resizing it as per max height and width.
Before starting this process I am showing mask with loading image and
hiding it after completing it. But I am not able to see this loader on
mobile device or on desktop browser even though I used large image.
Also I want to show loading image till browser complete its rendering of
processed image.
Thanks in advance.
for Code Please look into JsFiddle