Low-saliency prior for disocclusion hole filling in DIBR-synthesized images

Although images as viewed from intermediate virtual viewpoints can be synthesized using texture and depth maps from nearby camera views via depth-image-based rendering (DIBR), the rendered images contain disocclusion holes - spatial regions that were not visible in the reference views due to foreground object occlusion - that requires proper filling. In this paper, we introduce a new signal prior into the hole filling problem formulation: given disocclusion holes are part of the background and background tends to have low visual saliency, the extrapolated signal into the holes must also be of low saliency. Mathematically, we add a low-saliency prior to an exemplar-based inpainting algorithm, so that the best-matched block has both small matching cost and is of low visual saliency. Moreover, we compute a suitable Lagrange multiplier value for the saliency cost term via analysis of the reference images. Experimental results show that using a low-saliency prior can improve performance by 0.5 dB over a previous hole filling scheme.