This paper proposes a new method for blind mesh visual quality assessment (MVQA) based on a graph convolutional network. For that, we address the node classification problem to predict the perceived visual quality. First, two matrices represent the 3D mesh: a graph adjacency matrix and a feature matrix. Both matrices are used as input to a shallow graph convolutional network. The network consists of two convolutional layers followed by a max-pooling layer to provide the final feature representation. With this structure, the Softmax classifier predicts the quality score category without the reference mesh's availability. Experiments are conducted on four publicly available databases constructed explicitly for the mesh quality assessment task. We investigate several perceptual and visual features to select the most effective combination. Comparisons with the state-of-the-art alternative methods show the effectiveness of the proposed framework.
INDEX TERMSMesh visual quality assessment, graph convolutional networks, mesh graph representation, geometric attributes. Reference (NR) or Blind methods, no information about the reference is available [8]-[12]. Finally, in Reduced-Reference (RR) methods only part of the reference is available (i.e., features extracted from the reference) [13]-[17]. Most quality evaluation methods rely on the quality prediction technical tool and the feature type such as geometric (angles, curvature), topological (mesh connection), spatial (vertices and edges), frequency (Wavelet Transform [66], 21 Discrete cosine transform [67]), spectral (Laplace-Beltrami 22 operator [68]), etc. 23 One can distinguish two main categories of methods for 24 mesh quality assessment. The first category is based on 25 logistic regression to estimate the quality scores. A plethora 26 of such methods have been proposed in the literature and 27 have shown good performances [18]-[20], [25], [27]-[30]. 28 The second category relies on machine learning to predict 29 quality [31], [32]. More precisely, quality score estimation 30 is tackled into a classification context, or eventually, re-31 gression or regression by classification. In a previous work, 32 we have been the first to investigate Convolutional Neural 33 Network (CNN) as one of the most recent and relevant deep 34 learning tools to estimate the perceived visual quality of 3D 35 meshes [33]. 36 Intuitively, to handle simply CNN in our context, 2D im-37 ages are rendered from multiple views of the 3D mesh. Then, 38 each image is split into small patches, which are learned 39 to a convolutional neural network. As done for 2D images 40