Rethinking Neural Style Transfer: Generating Personalized and Watermarked Stylized Images

Neural style transfer (NST) has attracted many research interests recent years. The existing NST schemes could only generate one stylized image from a content-style image pair. They are weak in creating diverse and personalized artistic styles. On the other hand, the stylized images could easily be stolen and illegally redistributed when shared online, which has not been addressed at all in the existing NST schemes. In this paper, we propose a personalized and watermark-guided style transfer network (PWST-Net) to tackle the aforementioned issues. Our PWST-Net could generate diverse stylized images from a content-style image pair using different personalization keys. Once the style transfer is done, our stylized images are with watermarks naturally embedded for copyright protection. We propose a novel style encoder in our PWST-Net to progressively generate the stylized images, which contains a Guided Fusion (GF) block and a Style Transformation (ST) block. The GF block generates a coarse stylized image based on a personalized direction field that is specific to a personalization key and the style image. The ST block refines the coarse stylized image into the final stylized image. It embeds a watermark into the deep feature space of the stylized image during the style transfer. To make the stylized images more diverse, we further propose a new personalization loss for training our PWST-Net. Various experiments demonstrate the effectiveness of our proposed method for generating personalized and watermarked stylized images, which also outperforms the state-of-the-art NST schemes in terms of artistic visual appearance.