[Retracted] Efficient COVID-19 CT Scan Image Segmentation by Automatic Clustering Algorithm

Table 1

Parameters of each algorithm.

Algorithm/method	Parameters	Value
Improved whale optimization algorithm (IWOA)	a1	2 to 0
	a2	[−1, −2]
	b	1
	ℓ	[−1, 1]
Whale optimization algorithm (WOA)	a1	2 to 0
	a2	−1 to −2
	B	1
	ℓ	[−1, 1]
Salp swarm algorithm (SSA)	c1	2 to 0
Sine cosine algorithm (SCA)	A	2
	r1, r2, r3, r4	[0, 1]
Dim (Threshold number)	k	3
Upper bound Xmax	UB	255
Lower bound Xmin	LB	0