Fig. 1.

Schematic plot of randomized spatial downsampling to construct two downsampled sub-matrices. The blue and red pixels indicate the samples to construct the 1^st and the 12^th downsampled sub-matrix. To construct a downsampled sub-matrix, 3×3 pixels (block size) are randomly drawn in spatial domain (blue pixels in the green dashed box), and then the corresponding pixels along temporal domain (e.g. blue pixels in the yellow dashed box) are also selected. 12 downsampled sub-matrices (9×6 pixels each) then go through rSVD process in parallel using different CPU cores.