How to show a loader until images are ready then show them

I am currently working on a website (http://ift.tt/1OY2RmC). In the galleries, when your computer loads an image, it actually loads on the left of my screen and, once fully loaded, displays on the center like it should. I don't like this, is there a way to show some sort of loader instead of the image then show it once it's ready ?

I have seen some solutions on the internet but none seemed to fit my needs or i wouldn't get it to work, can anyone help ?

Thank you.