Fig. 2

The RIU-LBP features of typical blocks of three color models. The first row is the RGB image of eight typical blocks, (1) is the background block, (2)–(4) are the ‘suspicious blocks’, (5) the ‘few-white’, (6) the ‘normal’, (7) ‘clustered white’ and (8) ‘many-white’. The second row is the RIU-LBP feature of the intensity color model, the third row is the RIU-LBP feature of the R-channel color model, and the last row is the RIU-LBP feature of the gray color model. The horizontal axis represents the ten pattern of RIU-LBP, while the vertical axis represents the proportion of each pattern