Spatial-temporal recovery for hierarchical frame based video compressed sensing
In this paper, the hierarchical frame based video compressed sensing (CS) framework is proposed, which outperforms the traditional framework through the better exploitation of frames correlation with reference frames, the unequal sample subrates setting among frames in different layers and the reduction of the error propagation. By considering the spatial and temporal correlations of the video sequence, a spatial-temporal sparse representation based recovery is proposed for this framework. The similar blocks in both the current frame and these recovered reference frames are composed as a spatial-temporal group, which is defined as the unit of the sparse representation. By exploiting the low dimensional subspace description of each group, the video CS recovery is converted as a low-rank matrix approximation problem, which can be solved by exploiting the hard thresholding and the gradient descent. Experimental results show that the proposed method achieves better performance against both the state-of-art still-image CS recovery algorithms and the existing residual domain based video CS reconstruction approaches.