Get all images and background images on the page

gistfile1.js

getImageURLS : function () {
				var images = [],
					key = {},
					tags = document.getElementsByTagName('*'),
					url,
					el;


				for (var i = 0, len = tags.length; i < len; i++) {
					el = tags[i];
					if (el.currentStyle) {
						if (el.currentStyle.backgroundImage !== 'none') {
							//el.className += ' bg_found';
							url = el.currentStyle;
							//console.log(i + "  " + url);
						}
					}
					else if (window.getComputedStyle) {
						if (document.defaultView.getComputedStyle(el, null).getPropertyValue('background-image') !== 'none') {
							//el.className += ' bg_found';
							url = document.defaultView.getComputedStyle(el, null).getPropertyValue('background-image');
							//console.log(i + "  " + url);
						}
					}

					if (el.nodeName === "IMG" || el.tagName === "IMG") {
						url = el.src;

						if (url.indexOf("http://") > -1 && key[url] === undefined) {
							images.push($.trim(url));
							key[url] = images.length;
						}
					}


					if (url !== "" && url !== undefined) {
						if (url.indexOf("http://") > -1 && key[url] === undefined) {
							//var isURL = url.indexOf("static");
							// trim quotes
							url = url.indexOf('url("') > -1 ? url.slice(5, url.length - 2) : url;
							url = url.indexOf("url('") > -1 ? url.slice(5, url.length - 2) : url;
							url = url.indexOf('url(') > -1 ? url.slice(4, url.length - 1) : url;

							//console.log(i + "  " + url);
							images.push($.trim(url));
							key[url] = images.length;
							url = "";
						}
					}

				}


				return images;
			}