  Deep unsupervised domain adaptation (UDA) has recently received increasing
attention from researchers. However, existing methods are computationally
intensive due to the computation cost of Convolutional Neural Networks (CNN)
adopted by most work. To date, there is no effective network compression method
for accelerating these models. In this paper, we propose a unified Transfer
Channel Pruning (TCP) approach for accelerating UDA models. TCP is capable of
compressing the deep UDA model by pruning less important channels while
simultaneously learning transferable features by reducing the cross-domain
distribution divergence. Therefore, it reduces the impact of negative transfer
and maintains competitive performance on the target task. To the best of our
knowledge, TCP is the first approach that aims at accelerating deep UDA models.
TCP is validated on two benchmark datasets-Office-31 and ImageCLEF-DA with two
common backbone networks-VGG16 and ResNet50. Experimental results demonstrate
that TCP achieves comparable or better classification accuracy than other
comparison methods while significantly reducing the computational cost. To be
more specific, in VGG16, we get even higher accuracy after pruning 26% floating
point operations (FLOPs); in ResNet50, we also get higher accuracy on half of
the tasks after pruning 12% FLOPs. We hope that TCP will open a new door for
future research on accelerating transfer learning models.
