Added opacity/background support for images

README.md

@@ -172,6 +172,18 @@ Note that when specifying these options as html data-attributes, you should conv
 			<td>false</td>
 			<td>(Experimental) If true, will freeze the parallax effect when "over scrolling" in browsers like Safari to prevent unexpected gaps caused by negative scroll positions.</td>
 		</tr>
+		<tr>
+			<td>opacity</td>
+			<td>number</td>
+			<td>1</td>
+			<td>You can customize the image transparency.</td>
+		</tr>
+		<tr>
+			<td>background</td>
+			<td>string</td>
+			<td>null</td>
+			<td>You can customize the background behind the image (works with opacity < 1).</td>
+		</tr>
 	</tbody>
 </table>
 

parallax.js

@@ -134,6 +134,11 @@
       overflow: 'hidden'
     });
 
+    if (typeof self.opacity !== undefined)
+      this.$slider.css({ opacity: self.opacity });
+    if (typeof self.background !== undefined)
+      this.$mirror.css({ backgroundColor: self.background });
+
     this.$slider.addClass('parallax-slider').one('load', function() {
       if (!self.naturalHeight || !self.naturalWidth) {
         self.naturalHeight = this.naturalHeight || this.height || 1;