The number of recognized faces increased roughly monotonically, with horizontal asymptote at 27. At this scale, there is no visible improvement when using more than 11 eigenfaces. There doesn't seem to be a clear answer, unless you know exactly what percentage of error you can tolerate. (You will virtually never get 100% accuracy.)Tradeoffs: More eigenfaces give greater accuracy, but are take longer to process through the image.
2. You likely saw some recognition errors in step 3; show images of a couple. How reasonable were the mistakes? Did the correct answer at least appear highly in the sorted results?
As you can see, the misses were pretty close. The correct answer was usually the second or third best face.
This didn't turn out too well. There is a false positive on the wall. This probably occured because we had nothing in the eigenface set that was close enough to the baby's face. The second best match is the man's face.
