Number of datasets used for test 2.

The “Initial test” column reports the number of subjects (each subject contains approximately 1000 images) within the training and validation datasets for the initial testing subject used in test 2). Columns “Subject 1–5” represent the other 5 subjects for whom the networks were retrained in test 3). These 5 subjects were then used in turn as the testing subject. Note that these 5 subjects are different from the initial test subject used in test 2).