1 Open up your image.
2 Zoom in to one of the corner.
3 Take the pencil. (1 px Color: Black)
4 Draw a around the whole picture. Hold down "Shift" to get straight lines.
5 Take a matching color to the second one. Draw them inside the black one.
6 Take the black color again. And draw the finish lines inside the matching color.
You are done!
Picture