“…For example, an image named yaleB * * P00A 005E * * .pgm is distributed into the subset 005E to denote 5 degrees azimuth. Each subset contains images with different elevation ranged in [0,5,10,15,20,25,35,50,60,70,85,95,110,120,130]. In this way, total 15 subsets in Table 5 have Table 5 The sample number of each subset divided by azimuth Subset 000E 005E 010E 015E 020E 025E 035E 050E 060E 070E 085E 095E 110E 120E 130E No.…”