Style transfer has achieved great success and attracted a wide range of attention from both academic and industrial communities due to its flexible application scenarios. However, the dependence on pretty large VGG based autoencoder leads to existing style transfer models have a high parameter complexities which limits the application for resource-constrained devices. Unfortunately, the compression of style transfer model has less been explored. In parallel, study on the lottery ticket hypothesis (LTH) has shown great potential in finding extremely sparse matching subnetworks which can achieve on par or even better performance than original full networks when trained in isolation. In this work, we perform the first empirical study to verify whether such trainable networks also exist in style transfer models. From a wide range of style transfer methods, we choose two of the most popular style transfer models as the main testbeds, i.e., AdaIN and SANet, representing approaches of global and local transformation based style transfer respectively. Through extensive experiments and comprehensive analysis, we draw the following main conclusions. (𝑖) Compared with fixing VGG encoder, style transfer models can benefit more from training the whole network together. (𝑖𝑖) Using iterative magnitude pruning, we find the most sparse matching subnetworks at 89.2% in AdaIN and 73.7% in SANet, which suggests that Style transfer models can play lottery tickets too. (𝑖𝑖𝑖) Feature transformation module should also be pruned to get a sparser model without affecting the existence and quality of matching subnetworks. (𝑖𝑣) Besides AdaIN and SANet, other models such as LST, MANet, AdaAttN and MCCNet can also play lottert tickets, which shows that LTH can be generalized to various style transfer models.
CCS CONCEPTS• Computing methodologies → Non-photorealistic rendering.