Otsu Based Optimal Multilevel Image Thresholding Using Firefly Algorithm

Table 1

Comparison of objective values achieved with Otsu guided various FAs.

Test images	𝑚	Objective function values			Optimal threshold values
		BDFA	LFFA	FA	BDFA	LFFA	FA
Barbara	2	912.23	1023.28	1038.18	92, 158	90, 157	90, 156
	3	961.89	1523.21	1300.15	74, 122, 181	77, 124, 183	73, 120, 178
	4	1053.12	1593.82	1872.19	63, 96, 138, 191	61, 93, 137, 194	63, 96, 138, 191
	5	2428.05	1735.34	2164.01	47, 79, 122, 143, 191	46, 81, 119, 140, 193	44, 81, 120, 147, 188
Lena	2	1105.92	952.36	1052.66	90, 148	92, 149	92, 148
	3	1823.25	1271.83	1382.71	63, 119, 171	64, 117, 168	59, 111, 172
	4	1858.92	1639.26	1429.52	55, 100, 133, 183	57, 102, 138, 179	51, 98, 142, 176
	5	2017.63	1753.92	1742.08	49, 98, 124, 150, 185	53, 95, 128, 153, 187	49, 103, 128, 152, 186
Cameraman	2	1757.03	2071.36	1949.28	70, 148	70, 148	71, 148
	3	1941.42	2418.92	2023.41	51, 119, 163	54, 120, 158	53, 118, 162
	4	2056.55	2508.48	2205.20	49, 117, 144, 182	50, 113, 148, 174	49, 112, 148, 171
	5	2592.04	2691.82	2533.75	38, 91, 137, 170, 201	42, 93, 138, 169, 198	44, 92, 140, 173, 204
Living Room	2	1053.87	925.83	1104.07	84, 152	82, 155	84, 152
	3	1103.72	1053.62	1311.94	86, 141, 192	84, 138, 189	86, 141, 192
	4	1376.21	1329.02	1482.10	61, 107, 148, 189	64, 105, 140, 187	66, 109, 146, 191
	5	1855.16	1753.41	2153.12	62, 110, 129, 174, 195	66, 106, 138, 162, 203	61, 102, 135, 166, 198
Mandrill	2	903.63	1067.36	942.01	90, 147	88, 148	87, 148
	3	1053.01	1271.53	1101.83	101, 148, 193	102, 153, 178	100, 148, 182
	4	1187.49	1480.99	1359.22	70, 104, 133, 182	71, 109, 144, 175	71, 112, 138, 184
	5	1609.61	1622.76	1472.94	71, 111, 134, 167, 187	69, 104, 141, 156, 183	74, 102, 138, 158, 181
Jet	2	836.42	753.36	1102.53	90, 213	98, 210	91, 213
	3	1063.26	933.92	1491.25	93, 139, 203	98, 140, 211	96, 138, 215
	4	1293.84	1077.32	1870.55	63, 111, 142, 199	66, 108, 142, 205	58, 112, 138, 203
	5	1419.27	1121.66	2015.99	77, 92, 123, 151, 210	76, 96, 118, 149, 212	72, 95, 131, 148, 206
Boat	2	933.16	1047.83	1036.00	99, 176	98, 178	100, 181
	3	1076.37	1154.34	1204.36	60, 119, 183	64, 121, 178	61, 124, 182
	4	1192.01	1293.51	1528.04	48, 81, 138, 188	51, 86, 131, 184	52, 91, 133, 176
	5	1302.33	1504.18	1597.61	39, 67, 110, 158, 187	42, 65, 109, 153, 183	46, 72, 116, 148, 189
Zebra	2	1392.22	1073.25	1530.03	94, 151	94, 149	91, 148
	3	1503.87	1482.39	1677.92	82, 119, 188	81, 128, 185	78, 119, 189
	4	1893.2	1629.06	1853.33	70, 115, 132, 185	73, 110, 135, 204	69, 98, 128, 187
	5	2019.11	1865.35	2289.01	61, 95, 122, 153, 187	66, 93, 114, 146, 198	64, 97, 109, 145, 189
Snake	2	1398.36	1811.76	1195.21	77, 146	75, 147	74, 144
	3	1639.22	2071.04	1584.73	61, 114, 166	68, 110, 153	61, 121, 169
	4	1763.93	2191.55	1965.05	59, 93, 122, 175	54, 85, 123, 175	55, 76, 135, 182
	5	1973.06	2305.04	2100.46	52, 84, 121, 144, 189	48, 82, 130, 152, 182	51, 81, 128, 151, 179
Fish	2	925.38	825.25	733.25	102, 182	98, 182	100, 184
	3	955.26	1063.82	792.47	83, 143, 194	87, 144, 197	82, 139, 188
	4	1005.03	1205.13	1052.35	72, 125, 162, 203	63, 118, 172, 202	65, 122, 164, 198
	5	1052.77	1311.74	1360.35	57, 88, 134, 178, 197	48, 79, 141, 175, 202	54, 91, 127, 168, 206
Star Fish	2	1402.32	2061.65	1785.50	81, 159	82, 162	81, 158
	3	1611.54	2095.16	2106.76	62, 109, 181	59, 116, 187	65, 111, 175
	4	1638.02	2105.32	2201.45	57, 108, 142, 186	53, 112, 149, 178	48, 109, 138, 183
	5	1977.28	2411.77	2311.86	47, 88, 123, 157, 192	44, 83, 127, 163, 188	53, 78, 120, 152, 176
Sailor	2	600.23	854.05	831.06	53, 175	51, 178	50, 172
	3	712.93	1052.69	953.72	48, 126, 161	52, 132, 174	47, 136, 178
	4	730.18	1172.07	1106.35	41, 84, 142, 181	38, 91, 138, 178	41, 84, 142, 181
	5	826.24	1202.22	1290.60	39, 98, 127, 154, 186	41, 87, 122, 164, 192	45, 88, 133, 184, 203