A Multilevel Image Thresholding Method Based on Subspace Elimination Optimization

Table 3

Otsu’s maximum between class variance multilevel thresholding.

Image	Number of thresholds	Index	Exhaustion method	PSO	SSEO
Female	1	Variance	1145.60	1145.25	1145.60
		Thresholds	75	75	74
		Time(s)	0.085460	0.108066	0.122840
		Variance of the Time		7.58789E-06	8.52760E-06
	2	Variance	1347.10	1346.51	1346.83
		Thresholds	58 110	59 110	58 110
		Time(s)	0.280200	0.138602	0.155361
		Variance of the Time		1.11086E-04	2.80965E-06
	3	Variance	1444.70	1443.30	1444.04
		Thresholds	35 69 116	35 69 115	34 69 115
		Time(s)	18.351619	0.243077	0.227970
		Variance of the Time		2.55672E-03	2.30173E-05
	4	Variance	1487.40	1486.08	1486.85
		Thresholds	33 63 99 138	33 64 100 140	33 63 99 139
		Time(s)	1132.261655	0.766454	0.623988
		Variance of the Time		1.37653E-01	1.66319E-05
Jelly beans	1	Variance	1236.50	1236.26	1236.50
		Thresholds	139	139	138
		Time(s)	0.091220	0.109814	0.121777
		Variance of the Time		9.40414E-06	5.22426E-06
	2	Variance	1349.60	1349.42	1349.37
		Thresholds	89 155	89 155	103 166
		Time(s)	0.291574	0.142287	0.155299
		Variance of the Time		2.38194E-04	2.01919E-06
	3	Variance	1399.80	1399.14	1399.21
		Thresholds	85 145 186	84 145 185	85 145 185
		Time(s)	18.154217	7.573480	0.228355
		Variance of the Time		2.40161E+02	7.18563E-06
	4	Variance	1428.90	1428.18	1428.25
		Thresholds	76 119 160 188	74 119 161 187	76 119 159 188
		Time(s)	1244.274622	0.902986	0.620868
		Variance of the Time		2.61322E-01	4.99843E-05
San Diego	1	Variance	1712.50	1712.22	1712.44
		Thresholds	141	141	140
		Time(s)	0.096458	0.118310	0.130571
		Variance of the Time		7.54120E-06	1.14140E-05
	2	Variance	2074.00	2073.39	2073.53
		Thresholds	106 165	105 165	105 164
		Time(s)	0.300369	0.161998	0.168375
		Variance of the Time		4.54634E-04	1.30487E-06
	3	Variance	2188.80	2187.52	2187.48
		Thresholds	90 128 176	91 127 175	90 128 175
		Time(s)	18.114168	0.270145	0.245001
		Variance of the Time		1.74912E-02	1.38766E-05
	4	Variance	2249.20	2247.51	2248.10
		Thresholds	76 108 143 184	76 108 143 183	75 108 144 184
		Time(s)	1109.358181	0.899595	0.646769
		Variance of the Time		4.54533E-01	1.28512E-05
Sailboat	1	Variance	3689.50	3689.42	3689.48
		Thresholds	126	125	125
		Time(s)	0.097266	0.114995	0.132179
		Variance of the Time		1.18855E-05	7.49265E-06
	2	Variance	3976.00	3975.38	3975.50
		Thresholds	86 155	85 155	85 154
		Time(s)	0.305679	0.145634	0.170387
		Variance of the Time		1.24418E-04	6.29941E-06
	3	Variance	4113.80	4112.05	4112.05
		Thresholds	79 141 195	80 141 195	80 141 194
		Time(s)	18.482669	2.997714	0.247683
		Variance of the Time		7.63218E+01	1.6896E-05
	4	Variance	4.1825e+03	4181.03	4181.56
		Thresholds	67 110 158 199	67 109 158 200	66 110 157 198
		Time(s)	1260.671565	0.647337	0.704557
		Variance of the Time		1.27320E-01	4.11583E-02