Multilevel thresholding using grey wolf optimizer for image segmentation.

•A new method of multilevel thresholding for image segmentation using Grey Wolf Optimizer (GWO) is proposed.•Two objective functions-Kapur's entropy and Otsu's between class variance are used.•The proposed method is more stable than PSO and BFO based methods.•Yields solutions of higher quality than PSO and BFO based methods.•Faster than BFO but slower than PSO.