Back to Butterworth - a Fourier basis for 3D surface relief hole filling within RGB-D imagery

We address the problem of hole filling in RGB-D (color and depth) images, obtained from either active or stereo based sensing, for the purposes of object removal and missing depth estimation. This is performed independently on the low frequency depth information (surface shape) and the high frequency depth detail (relief) by way of a Fourier space transform and classical Butterworth high/low pass filtering. The high frequency detail is then filled using a texture synthesis method, whilst the low frequency shape information is inpainted using structural inpainting. Here, a classical non-parametric sampling approach is extended, using the concept of query expansion, to perform high frequency depth synthesis with the final output then recombined in Fourier space. In order to improve the overall depth relief (D) and edge detail accuracy, color information (RGB) is also used to constrain the sampling process within high frequency component completion. Experimental results demonstrate the efficacy of the proposed method outperforming prior work for generalized depth filling in the presence of high frequency surface relief detail.