“…It has been shown that CNN-learned features outperform hand-designed ones (local binary patterns or scale-invariant feature transform) in many areas, such as object classification [7], face gender recognition [8] or fashion detection [9]. More recently, CNNs have been introduced to NR-IQA and achieved state-of-the-art results [10,11,13]. It has also been shown that the depth of CNNs plays an important role in feature extraction [7,8,22,23].…”