Research Article

More Adaptive and Updatable: An Online Sparse Learning Method for Face Recognition

Algorithm 1

Online sparse learning algorithm.
Initialization:
(1)Obtain gallery set , testing set , initial salience evaluation vector , and facial feature description model .
(2)Set the initial value for the number of iterations: n = 1.
(3)Set the initial value for the sign vector (each element denotes whether the label of the testing sample is correct, “1” denotes “right” and “−1” denotes “wrong”) SV = 1.
(4)Randomly select a testing sample from .
Iteration:
(5)while {the number of the consecutive testing sample labeled incorrectly: k < 5} do:
(6).
(7)Compute the facial feature vector for with equation (1).
(8)Compute the label for with , , and the nearest neighbor model.
(9)Judge the correctness of according the criterion in Section 3.2: if is correct, then update according the gallery set update strategy in Section 3.3; if is incorrect, then repeat steps (4)∼(8).
(10)Construct the nearest neighbor set and next-nearest neighbor set : find the nearest neighbor samples of from , and all the nearest neighbor samples form set ; similarly, the next-nearest neighbor set is obtained.
(11)Construct positive and negative sample set and according to equation (7).
(12)Solve the optimization problem equations (9)∼(10) to obtain .
(13)Compute the salience evaluation vector β with equation (4).
(14)Compute with equation (1).
(15)Update
(16)Update
(17)n = n + 1.
(18) is equal to the number of element “−1” in vector [SV (n − 4), SV (n − 3), SV (n − 2), SV (n − 1), SV (n)].
(19)end while