Skeleton for a jQuery plugin to offer various operations to make large background images work out.

jquery.bigbg.js

/**
 * A jQuery plugin to resize the front page image to match the window.
 */
(function( $ ){
    
    var methods = {
        init: function () {
        },

        setFrontPageImageDimensions: function () {
          
            return this.each(function() {
                var $this = $(this);
                var windowWidth = $(window).width();
                var windowHeight = $(window).height();

                // TODO: Right now this just assumes images
                // that are wider than they are tall.  This 
                // function should eventually handle images
                // with the other dimensions as well.
                // -geoff@terrorware.com 2011-11-20

                // Calculate the image aspect ratio
                var aspectRatio = $this.width() / $this.height();
                console.debug(aspectRatio);

                // Calculate the new image dimensions
                var newWidth = windowWidth;
                var newHeight = Math.ceil(newWidth / aspectRatio); 

                // Update the image dimensions
                $this.width(windowWidth).height(newHeight);
            });

        }
    };


    $.fn.bigbg = function( method ) {
        // Method calling logic
        if ( methods[method] ) {
            return methods[ method ].apply( this, Array.prototype.slice.call( arguments, 1 ));
        } else if ( typeof method === 'object' || ! method ) {
            return methods.init.apply( this, arguments );
        } else {
            $.error( 'Method ' +  method + ' does not exist on jQuery.chiara' );
        }    

    };

})( jQuery );