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to extract features. This happens by convolving over the given image to generate invar-
iant features which are passed onto the next layer in a sequential fashion. It
is this con-
tinual passing of information from one layer to the next that leads to CNNs being so
robust and supple to occlusions, brightness changes etc.
The first application of CNNs was the Le-Net-5 [11]. However, the actual boom in
using CNNs for age and gender prediction started after D-CNN [12] was introduced for
image classification tasks. Rothe et al. [13] proposed DEX: Deep EXpectation of Ap-
parent Age for age classification using an ensemble of 20 networks on the cropped faces
of IMDB-Wiki dataset. Another popular work includes combining features
from Deep
CNN to features obtained from PCA done by Wang et al. [14].