fix for indexed format images

MediaBrowser.Controller/Drawing/ImageExtensions.cs

@@ -73,23 +73,23 @@ namespace MediaBrowser.Controller.Drawing
         {
             // http://msdn.microsoft.com/en-us/library/system.drawing.graphics.fromimage.aspx
 
-            if (format == PixelFormat.Indexed)
+            if ((format & PixelFormat.Indexed) == PixelFormat.Indexed)
             {
                 return false;
             }
-            if (format == PixelFormat.Undefined)
+            if ((format & PixelFormat.Undefined) == PixelFormat.Undefined)
             {
                 return false;
             }
-            if (format == PixelFormat.DontCare)
+            if ((format & PixelFormat.DontCare) == PixelFormat.DontCare)
             {
                 return false;
             }
-            if (format == PixelFormat.Format16bppArgb1555)
+            if ((format & PixelFormat.Format16bppArgb1555) == PixelFormat.Format16bppArgb1555)
             {
                 return false;
             }
-            if (format == PixelFormat.Format16bppGrayScale)
+            if ((format & PixelFormat.Format16bppGrayScale) == PixelFormat.Format16bppGrayScale)
             {
                 return false;
             }