“…the target-Background similarity perspective of clutter Several techniques are based on quantifying the degree of similarity between the target and the background or other distractor objects (Chang, Zhang, Liu, Yang, & Li, 2010;He et al, 2008;Hilgers, Vockel, Reynolds, & Pickard, 1997;Phillips & Sims, 1997;Xu, Shi, & Luo, 2012;Yang et al, 2011;Yang, Zhang, Xu, Chang, & He, 2007). In one study, for example, clutter was measured by comparing the similarity in luminance, contrast, and structure between the target and the background (Chang & Zhang, 2006).…”