K-SVD Based Point Cloud Coding for RGB-D Video Compression Using 3D Super-Point Clustering

In this paper, we present a novel 3D structure-awareness RGB-D video compression scheme, which applies the proposed 3D super-point clustering to partition the super-points in a colored point cloud, generated from an RGB-D image, into a centroid and a non-centroid super-point datasets. A super-point is a set of 3D points which are characterized with similar feature vectors. Input an RGB-D frame to the proposed scheme, the camera parameters are first used to generate a colored point cloud, which is segmented into multiple super-points using our multiple principal plane analysis (MPPA). These super-points are then grouped into multiple clusters, each of them characterized by a centroid super-point. Next, the median feature vectors of super-points are represented by the K singular value decomposition (K-SVD) based sparse codes. Given a super-point cluster, the sparse codes of the median feature vectors are very similar and thus the redundant information among them are easy to remove by the successive entropy coding. For each super-point, the residual super-point is computed by subtracting the feature vectors inside from the reconstructed median feature vector. These residual feature vectors are also collected and coded using the K-SVD based sparse coding to enhance the quality of the compressed point cloud. This process results in a multiple description coding scheme for 3D point cloud compression. Finally, the compressed point cloud is projected to the 2D image space to obtain the compressed RGB-D image. Experiments demonstrate the effectiveness of our approach which attains better performance than the current state-of-the-art point cloud compression methods.