Scroll background image untill the end not further - html

Question

I am working on a site and I don't want to repeat the background in the y direction.
I know how to do that.
But after the image I don't want background to becomes white or any other color.
I would like it to fix when it reaches that place or to let the background scroll slower then the rest of the site so I wont get to a white part.
Thanks a lot

Answer 1

I found this thread while I was looking for a solution to just this problem. I managed to write a short jQuery script adapting the hints given by Alex Morales.
With the following code, the background-image of the body scrolles down with the rest of the site until its bottom is reached. You can take a look at my homepage (http://blog.neonfoto.de) to see what it does.
$( window ).scroll( function(){
var ypos = $( window ).scrollTop(); //pixels the site is scrolled down
var visible = $( window ).height(); //visible pixels
const img_height = 1080; //replace with height of your image
var max_scroll = img_height - visible; //number of pixels of the image not visible at bottom
//change position of background-image as long as there is something not visible at the bottom
if ( max_scroll > ypos) {
$('body').css('background-position', "center -" + ypos + "px");
} else {
$('body').css('background-position', "center -" + max_scroll + "px");
}
});
This is actually the very first thing I did with JavaScript and JQuery, so any improvement would be great!

Answer 2

It's css3 so it's not super well supported, but I would look at the background-size property.

Answer 3

This is just off the top of my head but I think you will probably have to create a separate div containing the background image. If you place it in your markup before the main content and position the main content absolutely, it will sit behind the main content and at the top of the page. So:
CSS:
#background_div
{
background: url(images/some_image.png);
height: 600px;
width: 900px;
}
#main
{
height: 1200px;
width: 800px;
background: rgba(0, 0, 0, 0.25);
position: absolute;
top: 0;
}
HTML:
<div id="background_div"> </div>
Then what you do is you use javascript (I recommend jQuery) to detect the div's position on the screen.
jQuery:
This code grabbed from http://www.wduffy.co.uk/blog/keep-element-in-view-while-scrolling-using-jquery/
var $scrollingDiv = $("#background_div");
$(window).scroll(function(){
$scrollingDiv
.stop()
.animate({"marginTop": ($(window).scrollTop()) + "px"}, "slow" );
});