“…To avoid this problem, we define a cumulative mapping function boldVt(x), 29 , 30 which, for each pixel, stores the index of the source frame I1,I2,…,It−1 and the spatial shift relative to the source background region where the pixel was last visible. This mitigates the blurriness problem because source pixels used to inpaint the tool region are now being copied once via interpolation as opposed to multiple times.…”