Table 3: Training and testing time (sec) on digit “0” when increasing the number of training samples from 500 to 5000.

500100015002000300040005000

r242366453514605670735

N/r2.072.733.313.894.965.976.80

training stageKPCA1.75 ± 0.0556.98 ± 0.06618.72 ± 0.14035.46 ± 0.18579.97 ± 0.570154.65 ± 0.687255.01 ± 2.083
TP-IKPCA1.89 ± 0.0195.34 ± 0.0649.86 ± 0.08514.92 ± 0.07825.40 ± 0.01537.46 ± 0.03150.43 ± 0.411
ratio0.931.311.902.383.154.135.06

testing stageKPCA0.358 ± 0.0220.650 ± 0.0131.131 ± 0.0181.600 ± 0.0262.406 ± 0.0703.657 ± 0.1705.234 ± 0.293
TP-IKPCA0.181 ± 0.0120.266 ± 0.0140.323 ± 0.0170.371 ± 0.0160.429 ± 0.4290.465 ± 0.0110.511 ± 0.010
ratio1.982.444.064.315.618.0210.24