Abstract
Traditional 2D animation is labor-intensive, often requiring animators to manually draw twelve illustrations per second of movement. While automatic frame interpolation may ease this burden, 2D animation poses additional difficulties compared to photorealistic video. In this work, we address challenges unexplored in previous animation interpolation systems, with a focus on improving perceptual quality. Firstly, we propose SoftsplatLite (SSL), a forward-warping interpolation architecture with fewer trainable parameters and better perceptual performance. Secondly, we design a Distance Transform Module (DTM) that leverages line proximity cues to correct aberrations in difficult solid-color regions. Thirdly, we define a Restricted Relative Linear Discrepancy metric (RRLD) to automate the previously manual training data collection process. Lastly, we explore evaluation of 2D animation generation through a user study, and establish that the LPIPS perceptual metric and chamfer line distance (CD) are more appropriate measures of quality than PSNR and SSIM used in prior art.
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References
Bao, W., Lai, W.S., Ma, C., Zhang, X., Gao, Z., Yang, M.H.: Depth-aware video frame interpolation. In: Proceedings of the IEEE/CVF Conference on Computer Vision and Pattern Recognition, pp. 3703–3712 (2019)
Bao, W., Lai, W.S., Zhang, X., Gao, Z., Yang, M.H.: MEMC-Net: motion estimation and motion compensation driven neural network for video interpolation and enhancement. IEEE Trans. Pattern Anal. Mach. Intell. 43, 933–948 (2019)
Blau, Y., Michaeli, T.: The perception-distortion tradeoff. In: Proceedings of the IEEE Conference on Computer Vision and Pattern Recognition, pp. 6228–6237 (2018)
Cao, T.T., Tang, K., Mohamed, A., Tan, T.S.: Parallel banding algorithm to compute exact distance transform with the GPU. In: Proceedings of the 2010 ACM SIGGRAPH Symposium on Interactive 3D Graphics and Games, pp. 83–90 (2010)
Casey, E., Pérez, V., Li, Z.: The animation transformer: visual correspondence via segment matching. In: Proceedings of the IEEE/CVF International Conference on Computer Vision, pp. 11323–11332 (2021)
Choi, M., Kim, H., Han, B., Xu, N., Lee, K.M.: Channel attention is all you need for video frame interpolation. In: Proceedings of the AAAI Conference on Artificial Intelligence, vol. 34, pp. 10663–10671 (2020)
Dalstein, B., Ronfard, R., Van De Panne, M.: Vector graphics animation with time-varying topology. ACM Trans. Graph. (TOG) 34(4), 1–12 (2015)
Falcon, W., The PyTorch Lightning team: PyTorch Lightning (2019). https://doi.org/10.5281/zenodo.3828935. https://github.com/PyTorchLightning/pytorch-lightning
Felzenszwalb, P.F., Huttenlocher, D.P.: Distance transforms of sampled functions. Theory Comput. 8(1), 415–428 (2012)
Fourure, D., Emonet, R., Fromont, E., Muselet, D., Tremeau, A., Wolf, C.: Residual conv-deconv grid network for semantic segmentation. arXiv preprint arXiv:1707.07958 (2017)
Geirhos, R., Rubisch, P., Michaelis, C., Bethge, M., Wichmann, F.A., Brendel, W.: ImageNet-trained CNNs are biased towards texture; increasing shape bias improves accuracy and robustness. arXiv preprint arXiv:1811.12231 (2018)
He, K., Zhang, X., Ren, S., Sun, J.: Deep residual learning for image recognition. In: Proceedings of the IEEE Conference on Computer Vision and Pattern Recognition, pp. 770–778 (2016)
Huang, Z., Zhang, T., Heng, W., Shi, B., Zhou, S.: Rife: real-time intermediate flow estimation for video frame interpolation. arXiv preprint arXiv:2011.06294 (2020)
Ilg, E., Mayer, N., Saikia, T., Keuper, M., Dosovitskiy, A., Brox, T.: FlowNet 2.0: evolution of optical flow estimation with deep networks. In: Proceedings of the IEEE Conference on Computer Vision and Pattern Recognition, pp. 2462–2470 (2017)
Jaegle, A., et al.: Perceiver IO: a general architecture for structured inputs & outputs. arXiv preprint arXiv:2107.14795 (2021)
Jiang, H., Sun, D., Jampani, V., Yang, M.H., Learned-Miller, E., Kautz, J.: Super SloMo: high quality estimation of multiple intermediate frames for video interpolation. In: Proceedings of the IEEE Conference on Computer Vision and Pattern Recognition, pp. 9000–9008 (2018)
Kingma, D.P., Ba, J.: Adam: a method for stochastic optimization. arXiv preprint arXiv:1412.6980 (2014)
Krizhevsky, A., Sutskever, I., Hinton, G.E.: ImageNet classification with deep convolutional neural networks. In: Advances in Neural Information Processing Systems, vol. 25, pp. 1097–1105 (2012)
Liu, L., et al.: Learning by analogy: reliable supervision from transformations for unsupervised optical flow estimation. In: Proceedings of the IEEE/CVF Conference on Computer Vision and Pattern Recognition, pp. 6489–6498 (2020)
Maejima, A., et al.: Anime character colorization using few-shot learning. In: SIGGRAPH Asia 2021 Technical Communications, pp. 1–4 (2021)
Meyer, S., Djelouah, A., McWilliams, B., Sorkine-Hornung, A., Gross, M., Schroers, C.: PhaseNet for video frame interpolation. In: Proceedings of the IEEE Conference on Computer Vision and Pattern Recognition, pp. 498–507 (2018)
Meyer, S., Wang, O., Zimmer, H., Grosse, M., Sorkine-Hornung, A.: Phase-based frame interpolation for video. In: Proceedings of the IEEE Conference on Computer Vision and Pattern Recognition, pp. 1410–1418 (2015)
Narita, R., Hirakawa, K., Aizawa, K.: Optical flow based line drawing frame interpolation using distance transform to support inbetweenings. In: 2019 IEEE International Conference on Image Processing (ICIP), pp. 4200–4204. IEEE (2019)
Niklaus, S., Liu, F.: Softmax splatting for video frame interpolation. In: Proceedings of the IEEE/CVF Conference on Computer Vision and Pattern Recognition, pp. 5437–5446 (2020)
Niklaus, S., Mai, L., Liu, F.: Video frame interpolation via adaptive convolution. In: Proceedings of the IEEE Conference on Computer Vision and Pattern Recognition, pp. 670–679 (2017)
Niklaus, S., Mai, L., Liu, F.: Video frame interpolation via adaptive separable convolution. In: Proceedings of the IEEE International Conference on Computer Vision, pp. 261–270 (2017)
Okuta, R., Unno, Y., Nishino, D., Hido, S., Loomis, C.: CuPy: a NumPy-compatible library for NVIDIA GPU calculations. In: Proceedings of Workshop on Machine Learning Systems (LearningSys) in the Thirty-First Annual Conference on Neural Information Processing Systems (NIPS) (2017)
Park, J., Lee, C., Kim, C.S.: Asymmetric bilateral motion estimation for video frame interpolation. In: Proceedings of the IEEE/CVF International Conference on Computer Vision, pp. 14539–14548 (2021)
Paszke, A., et al.: Pytorch: an imperative style, high-performance deep learning library. In: Advances in Neural Information Processing Systems, vol. 32, pp. 8026–8037 (2019)
Qian, Z., Bo, W., Wei, W., Hai, L., Hui, L.J.: Line art correlation matching network for automatic animation colorization. arXiv e-prints, pp. arXiv-2004 (2020)
Ren, H., Li, J., Gao, N.: Two-stage sketch colorization with color parsing. IEEE Access 8, 44599–44610 (2019)
Riba, E., Mishkin, D., Shi, J., Ponsa, D., Moreno-Noguer, F., Bradski, G.: A survey on Kornia: an open source differentiable computer vision library for Pytorch (2020)
Ronneberger, O., Fischer, P., Brox, T.: U-Net: convolutional networks for biomedical image segmentation. In: Navab, N., Hornegger, J., Wells, W.M., Frangi, A.F. (eds.) MICCAI 2015. LNCS, vol. 9351, pp. 234–241. Springer, Cham (2015). https://doi.org/10.1007/978-3-319-24574-4_28
Sampat, M.P., Wang, Z., Gupta, S., Bovik, A.C., Markey, M.K.: Complex wavelet structural similarity: a new image similarity index. IEEE Trans. Image Process. 18(11), 2385–2401 (2009)
Simo-Serra, E., Iizuka, S., Ishikawa, H.: Mastering sketching: adversarial augmentation for structured prediction. ACM Trans. Graph. (TOG) 37(1), 1–13 (2018)
Simo-Serra, E., Iizuka, S., Sasaki, K., Ishikawa, H.: Learning to simplify: fully convolutional networks for rough sketch cleanup. ACM Trans. Graph. (TOG) 35(4), 1–11 (2016)
Siyao, L., et al.: Deep animation video interpolation in the wild. In: Proceedings of the IEEE/CVF Conference on Computer Vision and Pattern Recognition, pp. 6587–6595 (2021)
Souček, T., Lokoč, J.: TransNet v2: an effective deep network architecture for fast shot transition detection. arXiv preprint arXiv:2008.04838 (2020)
Sun, D., Yang, X., Liu, M.Y., Kautz, J.: PWC-Net: CNNs for optical flow using pyramid, warping, and cost volume. In: Proceedings of the IEEE Conference on Computer Vision and Pattern Recognition, pp. 8934–8943 (2018)
Teed, Z., Deng, J.: RAFT: recurrent all-pairs field transforms for optical flow. In: Vedaldi, A., Bischof, H., Brox, T., Frahm, J.-M. (eds.) ECCV 2020. LNCS, vol. 12347, pp. 402–419. Springer, Cham (2020). https://doi.org/10.1007/978-3-030-58536-5_24
Virtanen, P., et al.: SciPy 1.0: fundamental algorithms for scientific computing in Python. Nat. Methods 17, 261–272 (2020). https://doi.org/10.1038/s41592-019-0686-2
Whited, B., Noris, G., Simmons, M., Sumner, R.W., Gross, M., Rossignac, J.: BetweenIT: an interactive tool for tight inbetweening. In: Computer Graphics Forum, vol. 29, pp. 605–614. Wiley Online Library (2010)
Xu, X., Siyao, L., Sun, W., Yin, Q., Yang, M.H.: Quadratic video interpolation. arXiv preprint arXiv:1911.00627 (2019)
Yagi, Y.: A filter based approach for inbetweening. arXiv preprint arXiv:1706.03497 (2017)
Zhang, R., Isola, P., Efros, A.A., Shechtman, E., Wang, O.: The unreasonable effectiveness of deep features as a perceptual metric. In: Proceedings of the IEEE Conference on Computer Vision and Pattern Recognition, pp. 586–595 (2018)
Acknowledgements
The authors would like to thank Lillian Huang and Saeed Hadadan for their discussion and feedback, as well as NVIDIA for GPU support.
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Chen, S., Zwicker, M. (2022). Improving the Perceptual Quality of 2D Animation Interpolation. In: Avidan, S., Brostow, G., Cissé, M., Farinella, G.M., Hassner, T. (eds) Computer Vision – ECCV 2022. ECCV 2022. Lecture Notes in Computer Science, vol 13677. Springer, Cham. https://doi.org/10.1007/978-3-031-19790-1_17
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