If you are using multiple sizes of an image on a web page and these are static widths and heights, the best way I'd suggest to get the images loaded quicker is to store multiple images of different sizes on your server and access the correct size for each image you're displaying. This way if you're only viewing a small size (say 400x400), you don't have to download an image that is much larger(say 2000x2000) and size it down. That'll make things quicker.