Fig. 4

Sliding window processing of second-stage detection. The left image contains the first-stage detection result, where the foreground regions are outlined by green squares. The right-hand image is a representation of the sliding window process for a single foreground region. The black dots in the green square region represent K×K foreground candidate pixels, whereas the red dot denotes the pixel selected for foreground detection. The size of the sliding window is L×L, as shown by the blue square. The black square represents a neighborhood patch of the current sliding window