Table 8.

Comparison with previous studies.

	Bahoura [15]	Lin et al. [27]	Zhang et al. [14]	Yu et al. [13]	This Study
Method	GMM + MFCC	MA + BPNN	Sampling	Correlation	Bilateral filter + SVMs
			entropy	coefficient
Performance	SE= 0.946	SE= 1.0	Not mentioned	SE= 0.83	SE= 0.887
	SP= 0.919	SP= 0.895		SP= 0.86	SP= 0.939
	PER=0.932	PER= 0.946		PER= 0.844	PER= 0.912
Platform	Laptop	Laptop	Laptop and PDA	Laptop and PDA	Standalone
					FPGA system
Speed	Slow	Slow	Fast	Fast	Very Fast