“…From the perspective of distortion type, objective PCQA models can be classed as geometry distortion metrics [16], [25], [26], [28]- [30], [33], [39], [40], [79] and geometry-plus-color distortion metrics [12], [21], [23], [28], [29], [32], [35], [37], [38], [44]- [47], [49]- [60]. From the perspective of feature extraction, objective PCQA models can be classed as pointbased models [16], [25], [28]- [30], [33], [35], [37]- [40], [44], [46], [47], [49]- [51], [54]- [57], [59], [60] and projection-based models [12], [21], [23], [32], [45], [52], [53], [58].…”