Abstract: A device comprising at least one processing logic configured for: obtaining an input vector representing an input data sample; until a stop criterion is met, performing successive iterations of: using an autoencoder trained using a set of reference vectors to encode the input vector into a compressed vector, and decode the compressed vector into a reconstructed vector; calculating a reconstruction loss between the reconstructed and the input vectors, and a gradient of the reconstruction loss; updating said input vector for the subsequent iteration using said gradient.