how to zoom in an image using jquery

I was just wondering how it's possible to zoom in a pic using jquery,

something like this web site,

when you click on the big image it'll zoom in and you can move your cursor and see the other part of the pic while zoomed in,

I'd appreciate it if someone could show me a link or put me in the right direction.

Solution

They don't zoom in, what is really happening is that when you click the Zoom text, the image inside the div is replaced by a larger version of that image. And overflow is set to hidden.

As you move your cursor, using some clever JavaScript and DOM handling, the image is simply moved relatively accordingly, creating the effect you are actually zooming in the picture.

I'll try to create up a simple example for you.

EDIT

Sorry took a while but here it is:

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en">
<head>
    <title>Example</title>

    <script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.3.2/jquery.min.js"></script>
    <script type="text/javascript">
        $(function() {
                var fullWidth = 864; // Width in pixels of full-sized image
                var fullHeight = 648; // Height in pixels of full-sized image
                var thumbnailWidth = 389;  // Width in pixels of thumbnail image
                var thumbnailHeight = 292;  // Height in pixels of thumbnail image

                // Set size of div
                $('#picture').css({
                        'width': thumbnailWidth+'px',
                        'height': thumbnailHeight+'px'
                });

                // Hide the full-sized picture
                $('#full').hide();

                // Toggle pictures on click
                $('#picture').click(function() {
                        $('#thumbnail').toggle();
                        $('#full').toggle();
                });

                // Do some calculations
                $('#picture').mousemove(function(e) {
                        var mouseX = e.pageX - $(this).attr('offsetLeft'); 
                        var mouseY = e.pageY - $(this).attr('offsetTop'); 

                        var posX = (Math.round((mouseX/thumbnailWidth)*100)/100) * (fullWidth-thumbnailWidth);
                        var posY = (Math.round((mouseY/thumbnailHeight)*100)/100) * (fullHeight-thumbnailHeight);

                        $('#full').css({
                                'left': '-' + posX + 'px',
                                'top': '-' + posY + 'px'
                        });
                });
        });
    </script>

    <style type="text/css">
        #picture {
                overflow: hidden;
                position: relative;
                border: 1px solid #000000;
        }

        #thumbnail {
                cursor: pointer;
        }

        #full {
                position: relative;
                cursor: crosshair;
        }
    </style>
</head>

<body>
    <div id="picture">
        <img alt="" id="thumbnail" src="http://img202.imageshack.us/img202/8403/93629325.jpg" />
        <img alt="" id="full" src="http://img111.imageshack.us/img111/4734/tbmecsekyellowflower.jpg" />
    </div>
</body>
</html>

You will need to adjust the thumbnail and full-sized image width and height accordingly. But simply copy paste the above to see an example of an image hosted on imageshack.