“…Given a new instance, this encoding methodology uses the normalized frequency vector of code occurrence as the final feature vector. Bag-of-words encoding is widely employed by a large number of skeleton-based human representations [174,143,144,210,186,109,150,127,188,189,115,152,190,192,159,147,165,167,179,162,218,219]. According to how the dictionary is learned, the encoding methods can be broadly categorized into two groups, based on clustering or sparse coding.…”