fireproof's links are interesting. A little more elaborations on Go Eye following the topic.
Go Eye is specific for computer generated images. For camera shots, it is hard (Sometimes it can but most of the time cannot). Most of the time, the author uses it for answering life-and-death or middle image questions from Go forums, when people post images only.
Go Eye doesn't need to have user involvement in finding board corner at first try (User can drag a rectangle to limit the area if first trial fails). And it recognizes incomplete board (typically used life-and-death problems) and lets user have a directional control to shift the board in four directions after recognition.
For some special board/stone background or patterns, Go Eye is not able to recognize well. A color neutral algorithm would be good for Go Eye to improve.