假设输入图是引导图的线性变换，但是输入图需要滤波。如果输入和引导是同一图，效果等于局部均值滤波（box filter）。

Depth Maps Restoration for Human Using RealSense: 如果RGBD相机的D图有洞洞，可以用RGB的depth prediction引导填充。

Followed with horrible mathematical derivation.

cluster pixels, segment motion, magnify displacement

How it works?

Morphological operations such as erosion.