Evaluating virtual image quality using the side-views information fusion and depth maps

Three Dimensional (3D) image quality assessment is a challenging problem as compared to 2D images due to their different nature of acquisition, representation, coding, and display. The additional dimension of depth in multiview video plus depth (MVD) format is exploited to obtain images at novel intermediate viewpoints using depth image based rendering (DIBR) techniques, enabling 3D television and free-viewpoint television (FTV) applications. Depth maps introduce various quality artifacts in the DIBR-synthesized (virtual) images. In this paper, we propose a novel methodology to evaluate the quality of synthesized views in absence of the corresponding original reference views. It computes the statistical characteristics of the side views from whom the virtual view is generated, and fuses this information to estimate the statistical characteristics of the cyclopean image which are compared to those of the synthesized image to evaluate its quality. In addition to texture images, the proposed algorithm also considers the depth maps in evaluating the quality of the synthesized images. The algorithm blends two quality metrics, one estimating the texture distortion in the synthesized texture image induced by compression, transmission, 3D warping, or other causes and the second one determining the distortion of the depth maps. The two metrics are combined to obtain an overall quality assessment of the synthesized image. The proposed Synthesized Image Quality Metric (SIQM) is tested on the challenging MCL-3D and SIAT-3D datasets. The evaluation results show that the proposed metric significantly improves over state-of-the-art 3D image quality assessment algorithms.