Fig. 11

Typical failure (absolute error larger than 20 years) examples. Digits in black represent the ground truth age. For the testing sample, bracketed digits represent the estimated age, whereas red indicates an overestimate and blue indicates an underestimate. For the NN training sample, gray digits indicate the NN distance from the above testing sample. a Failures with small NN distances (less than 2.5E+04) from the training samples, b Failures with large NN distances (more than 4.0E+04) from the training samples