Below are 20 eigenfaces. Eigenface on the left has higher eigenvalue.
Plot showing eigenvalues in sorted order.
Plot showing accuracy with k from 1 to 20.
Some of the non-face images I used are
The reconstruction error is sum of squared distance between reconstructed image and original image.
K is set to be 20. The minimum error for non-face images is 255.34, while maximum error for face images is 241.00
So the threshold could be any value between 241 and 255.34, such as 250.
The three face images whose reconstruction errors are close to but smaller than threshold are
The two non-face images whose reconstruction errors are close to but larger than threshold are