This was written by Eric (http://stackoverflow.com/users/102441/eric), in response to this question on SO: http://stackoverflow.com/questions/1682495/jquery-resize-to-aspect-ratio Resizes images to fit their parent, blowing it out of the sides if necessary to completely fill any white space (and the parent container is set to overflow:hidden).

fullImage.js

jQuery.fn.fitToParent = function()
{
    this.each(function()
    {
      var width  = $(this).width();
    	var height = $(this).height();
    	var parentWidth  = $(this).parent().width();
    	var parentHeight = $(this).parent().height();

    	if(width/parentWidth < height/parentHeight)
    	{
    		newWidth  = parentWidth;
    		newHeight = newWidth/width*height;
    	}
    	else
    	{
    		newHeight = parentHeight;
    		newWidth  = newHeight/height*width;
    	}
    	margin_top  = (parentHeight - newHeight) / 2;
    	margin_left = (parentWidth  - newWidth ) / 2;

    	$(this).css({'margin-top' :margin_top  + 'px',
    	             'margin-left':margin_left + 'px',
    	             'height'     :newHeight   + 'px',
    	             'width'      :newWidth    + 'px'});
    });
};