Fast Loading Time For Image

[Abbster22]

I know that there are many scripts (Jquery and Javascript) and CSS tricks that allow an image as a background to scale with the browser.

There's this one website that I find a very good example of what I would like to achieve, which is below:
http://g2geogeske.com/

I wanted to know on this website how they are able to have a huge image file like this website has download in 3 seconds or less?

[DrDOS]

Crafty, they are. Look at the very bottom of the page source for a div named backgroundimage. It's really the foreground image of a td. Many of the foreground images over it are actually the backgrounds of other divs. Clever use of z-index to make a foreground act like a background and load quickly.

[Abbster22]

Yeah that is really crafty of them! My question is why is it that when they used the image as a foreground of a td it loads faster?

So if I wanted to use this for a website that I create, all I have to do is do what they did below and copy some of the CSS from their style sheet? I wanted to be able to use the full image without "cropping it", meaning I don't want to expand the picture any more than 100% instead of like how they have it, 200%.

[DrDOS]

I'm sure that one reason it loads so fast is that it has 1/4 the area and file size that a 100% image would.

[jibin]

the image is 277.93 KB size.
compared to the the size in pixels it is very small.
so the real trick is on the image. it is a highly optimized image.