Multilevel Thresholding Segmentation Based on Harmony Search Optimization

Table 3

Result after appling the HSMA using Otsu’s function to the set of benchmark images.

Image	𝑘	Thresholds 𝑥^𝑐best	PSNR	STC
Camera man	2	70, 144	17.247	2.30𝐸−12
	3	59, 119, 156	20.211	1.55𝐸−02
	4	42, 95, 140, 170	21.533	2.76𝐸−12
	5	36, 82, 122, 149, 173	23.282	5.30𝐸−03
Lena	2	91, 150	15.401	9.22𝐸−13
	3	79, 125, 170	17.427	2.99𝐸−02
	4	73, 112, 144, 179	18.763	2.77𝐸−01
	5	71, 107, 134, 158, 186	19.443	3.04𝐸−01
Baboon	2	97, 149	15.422	6.92𝐸−13
	3	85, 125, 161	17.709	1.92𝐸−02
	4	71, 105, 136, 167	20.289	5.82𝐸−02
	5	66, 97, 123, 147, 173	21.713	4.40𝐸−01
Hunter	2	51, 116	17.875	2.30𝐸−12
	3	36, 86, 135	20.350	2.30𝐸−12
	4	27, 65, 104, 143	22.203	1.22𝐸−02
	5	22, 53, 88, 112, 152	23.703	1.84𝐸−12
Airplane	2	113, 173	15.029	9.22𝐸−13
	3	92, 144, 190	18.854	4.83𝐸−01
	4	84, 129, 172, 203	20.735	7.24𝐸−01
	5	68, 106, 143, 180, 205	23.126	8.38𝐸−01
Peppers	2	72, 138	16.299	1.38𝐸−12
	3	65, 122, 169	18.359	4.61𝐸−13
	4	50, 88, 128, 171	20.737	4.61𝐸−13
	5	48, 85, 118, 150, 179	22.310	1.84𝐸−012
Living room	2	87, 145	15.999	1.15𝐸−12
	3	76, 123, 163	18.197	6.92𝐸−12
	4	56, 97, 132, 168	20.673	9.22𝐸−12
	5	49, 88, 120, 146, 178	22.225	2.86𝐸−02
Blonde	2	106, 155	14.609	6.92𝐸−13
	3	53, 112, 158	19.157	9.23𝐸−13
	4	50, 103, 139, 168	20.964	5.48𝐸−01
	5	49, 92, 121, 152, 172	22.409	6.50𝐸−01
Bridge	2	91, 56	13.943	4.61𝐸−13
	3	72, 120, 177	17.019	7.10𝐸−01
	4	63, 103, 145, 193	18.872	2.91𝐸−01
	5	56, 91, 124, 159, 201	20.539	3.57𝐸−01
Butterfly	2	99, 151	13.934	7.30𝐸−02
	3	82, 119, 160	16.932	6.17𝐸−01
	4	71, 102, 130, 163	19.259	3.07𝐸+00
	5	62, 77, 109, 137, 167	21.450	3.87𝐸+00
Lake	2	85, 154	14.638	4.61𝐸−13
	3	78, 140, 194	15.860	1.84𝐸−12
	4	67, 110, 158, 198	17.629	2.68𝐸−01
	5	57, 88, 127, 166, 200	19.416	1.12𝐸−01