âShift: A Zero FLOP, Zero Parameter Alternative to Spatial Convolutionsâ, 2017-11-22 (; similar)â :
Neural networks rely on convolutions to aggregate spatial information. However, spatial convolutions are expensive in terms of model size and computation, both of which grow quadratically with respect to kernel size. In this paper, we present a parameter-free, FLOP-free âshiftâ operation as an alternative to spatial convolutions. We fuse shifts and point-wise convolutions to construct end-to-end trainable shift-based modules, with a hyperparameter characterizing the tradeoff between accuracy and efficiency.
To demonstrate the operationâs efficacy, we replace ResNetâs 3Ă3 convolutions with shift-based modules for improved CIFAR-10 and CIFAR-100 accuracy using 60% fewer parameters; we additionally demonstrate the operationâs resilience to parameter reduction on ImageNet, outperforming ResNet family members.
We finally show the shift operationâs applicability across domains, achieving strong performance with fewer parameters on classification, face verification and style transfer.