Another method of Face Recognition is Neural Network based recognition. In this method we use Discrete Cosine Transforms to reduce the image to a few DCT coefficients which represent the image and then using an Artificial Neural Network we train the image to be identified onto the image-set in the database. We can use DCT coefficients or Eigenfaces alone for face recognition, but as the size of the database increases the time taken for recognizing the faces increases. Due to this we use Artificial Neural Networks for large databases in which the mapping of the coefficients of a test image (i.e. image to be identified) over the entire database takes almost constant time irrespective of the size of the database.
