Multi-level image segmentation is a critical task in image processing that involves multiple threshold values. As the high computational cost of an exhaustive search is inefficient and cumbersome, the optimal thresholds algorithms make for a better path to venture; hence a comparison of optimization algorithms to set the optimal thresholds is highly essential and beneficial. In this paper, a practical comparison is made to deduce the best optimization technique amongst the whale optimization and antlion optimization algorithm, to solve the multilevel threshold problem, to find the optimal multilevel thresholds. Otsu's function is maximized to perform optimized thresholding-based image segmentation. The experimental results showed that the Antlion optimization algorithm gave better performance in solving the problem for higher level multi-thresholding.