Fig. 2

a STD of all features extracted from the pre-trained AlexNet (FCL7). b STD of discriminant features after PCA extracted from the pre-trained AlexNet (FCL7). The central redline (inside the blue boxes) indicates the median, and the bottom and top edges of the blue-box indicate the 25th and 75th percentiles of data points, respectively. The whiskers extend to the most extreme data points not considered outliers, and the outliers are plotted individually using the ‘ + ’ symbol