Autoencoder-levenberg-marquardt back-propagation: a training algorithm in recognizing handwriting images
摘要
While neural networks often reduce irrelevant noise by extracting useful patterns, this paper presents a method for training a neural network to extract meaningful features from a noisy database at a specific scale by applying the Levenberg-Marquardt second order optimization. Several noise types were added to the handwritten raw database used; Gaussian, salt-and-pepper, and speckle noise. The results showed model’s robustness against the type of salt-and-pepper noise, moderate behavior against the type of speckle and sensitivity to high Gaussian variance noise. Among the metrics used, F1-score and True Positive Rate were found to be the most reliable, rather than accuracy. The results also showed that the range (0.05-0.07) of noise variance and density is the best level for practical operation. Further studies are needed to test other methods of minimizing errors, such as Adam, Adagrad,..etc..