Steps to solve a maze with Photoshop.

1) find a maze image that has good solid lines
(maze should have an open start and finish point)

2) use magic wand to select the border of the maze

3) in the menu do: select > modify > expand and enlarge by 3-4 pixels

4) make a new layer and then select a bright color(red works well)

5) fill the selection with that color

6) in the menu do: select > modify > contract and contract by 2-3 pixels

7) clear the selection and finally deselect

(Seen here)