This is an extremely basic tutorial on how to turn an image into a simple white outline.
1. Open up the image you wish to turn into a white outline.
2. Filter > Blur > Smart Blur (Radius -20*, Threshold - 100, Quality - High, Mode - Edge Only).
And you're done! Here is my end result:

Can you guess what image that is? :P
* - depending on how much of the line you want, you can change this around a bit. I thought that 20 looked the best on most images though.
Creator B)