Towards Efficient U-Nets: A Coupled and Quantized Approach.In this paper, we propose to couple stacked U-Nets for efficient visual landmark localization.  The key idea is to globally reuse features of the same semantic meanings across the stacked U-Nets.  To further improve the efficiency, we quantize the parameters, intermediate features, and gradients of the coupled U-Nets to low bit-width numbers. 
U-Nets
To further improve the efficiency, we quantize the parameters, intermediate features, and gradients of the coupled U-Nets to low bit-width numbers. 
coupled U-Nets