"Each pixel is assumed pure and typically labeled as a single land use land cover type." (Li et al., 2014)
Li Miao, Zang Shuying, Zhang Bing, Li Shanshan and Wu Changshan. "A Review of Remote Sensing Image Classification Techniques: the Role of Spatio-contextual Information". European Journal of Remote Sensing 47, no. 1 (2014): 389-411.