Block diagram of the classification framework comprising 3 main blocks: (1) Feature learning (learn a codebook from the train data), (2) Feature encoding (use the learned codebook to encode the train and test data), (3) Classification (use the encoded train and test data to fit and evaluate a discriminative classifier).

<p>Block diagram of the classification framework comprising 3 main blocks: (1) Feature learning (learn a codebook from the train data), (2) Feature encoding (use the learned codebook to encode the train and test data), (3) Classification (use the encoded train and test data to fit and evaluate a discriminative classifier).</p>