Abstract
Deep learning approaches have achieved great success in addressing the problem of optical flow estimation. The keys to success lie in the use of cost volume and coarse-to-fine flow inference. However, the matching problem becomes ill-posed when partially occluded or homogeneous regions exist in images. This causes a cost volume to contain outliers and affects the flow decoding from it. Besides, the coarse-to-fine flow inference demands an accurate flow initialization. Ambiguous correspondence yields erroneous flow fields and affects the flow inferences in subsequent levels. In this paper, we introduce LiteFlowNet3, a deep network consisting of two specialized modules, to address the above challenges. (1) We ameliorate the issue of outliers in the cost volume by amending each cost vector through an adaptive modulation prior to the flow decoding. (2) We further improve the flow accuracy by exploring local flow consistency. To this end, each inaccurate optical flow is replaced with an accurate one from a nearby position through a novel warping of the flow field. LiteFlowNet3 not only achieves promising results on public benchmarks but also has a small model size and a fast runtime.
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References
Bailer, C., Taetz, B., Stricker, D.: Flow fields: dense correspondence fields for highly accurate large displacement optical flow estimation. In: ICCV, pp. 4015–4023 (2015)
Brabandere, B.D., Jia, X., Tuytelaars, T., Gool, L.V.: Dynamic filter networks. In: NIPS (2016)
Brox, T., Bruhn, A., Papenberg, N., Weickert, J.: High accuracy optical flow estimation based on a theory for warping. In: Pajdla, T., Matas, J. (eds.) ECCV 2004. LNCS, vol. 3024, pp. 25–36. Springer, Heidelberg (2004). https://doi.org/10.1007/978-3-540-24673-2_3
Butler, D.J., Wulff, J., Stanley, G.B., Black, M.J.: A naturalistic open source movie for optical flow evaluation. In: Fitzgibbon, A., Lazebnik, S., Perona, P., Sato, Y., Schmid, C. (eds.) ECCV 2012. LNCS, vol. 7577, pp. 611–625. Springer, Heidelberg (2012). https://doi.org/10.1007/978-3-642-33783-3_44
Dai, J., et al.: Deformable convolutional networks. In: ICCV, pp. 764–773 (2017)
Dosovitskiy, A., et al.: FlowNet: learning optical flow with convolutional networks. In: ICCV, pp. 2758–2766 (2015)
Geiger, A., Lenz, P., Urtasun, R.: Are we ready for autonomous driving? In: CVPR, pp. 3354–3361 (2012)
Horn, B.K.P., Schunck, B.G.: Determining optical flow. Aritif. Intell. 17, 185–203 (1981)
Hui, T.W., Loy, C.C.: Supplementary material for LiteFlowNet3: resolving correspondence ambiguity for more accurate optical flow estimation (2020)
Hui, T.W., Tang, X., Loy, C.C.: LiteFlowNet: a lightweight convolutional neural network for optical flow estimation. In: CVPR, pp. 8981–8989 (2018)
Hui, T.W., Tang, X., Loy, C.C.: A lightweight optical flow CNN - revisiting data fidelity and regularization. TPAMI (2020). https://doi.org/10.1109/TPAMI.2020.2976928
Hur, J., Roth, S.: Iterative residual refinement for joint optical flow and occlusion estimation. In: CVPR, pp. 5754–5763 (2019)
Ilg, E., Mayer, N., Saikia, T., Keuper, M., Dosovitskiy, A., Brox, T.: FlowNet2.0: evolution of optical flow estimation with deep networks. In: CVPR, pp. 2462–2470 (2017)
Ilg, E., Saikia, T., Keuper, M., Brox, T.: Occlusions, motion and depth boundaries with a generic network for disparity, optical flow or scene flow estimation. In: Ferrari, V., Hebert, M., Sminchisescu, C., Weiss, Y. (eds.) ECCV 2018. LNCS, vol. 11216. Springer, Cham (2018). https://doi.org/10.1007/978-3-030-01258-8_38
Janai, J., Güney, F., Ranjan, A., Black, M., Geiger, A.: Unsupervised learning of multi-frame optical flow with occlusions. In: Ferrari, V., Hebert, M., Sminchisescu, C., Weiss, Y. (eds.) ECCV 2018. LNCS, vol. 11220, pp. 713–731. Springer, Cham (2018). https://doi.org/10.1007/978-3-030-01270-0_42
Jiang, H., Sun, D., Jampani, V., Lv, Z., Learned-Miller, E., Kautz, J.: SENSE: a shared encoder network for scene-flow estimation. In: ICCV, pp. 3195–3204 (2019)
Kang, S.B., Szeliski, R., Chai, J.: Handling occlusions in dense multi-view stereo. In: CVPR, pp. 103–110 (2001)
Liu, P., Lyu, M., King, I., Xu, J.: SelFlow: self-supervised learning of optical flow. In: CVPR, pp. 4566–4575 (2019)
Lu, Y., Valmadre, J., Wang, H., Kannala, J., Harandi, M., Torr, P.H.S.: Devon: deformable volume network for learning optical flow. In: Leal-Taixé, L., Roth, S. (eds.) ECCV 2018. LNCS, vol. 11134, pp. 673–677. Springer, Cham (2019). https://doi.org/10.1007/978-3-030-11024-6_50
Mayer, N., et al.: A large dataset to train convolutional networks for disparity, optical flow, and scene flow estimation. In: CVPR, pp. 4040–4048 (2016)
Meister, S., Hur, J., Roth, S.: UnFlow: unsupervised learning of opticalflow with a bidirectional census loss. In: AAAI, pp. 7251–7259 (2018)
Menze, M., Geiger, A.: Object scene flow for autonomous vehicles. In: CVPR, pp. 3061–3070 (2015)
Papenberg, N., Bruhn, A., Brox, T., Didas, S., Weickert, J.: Highly accurate optic flow computation with theoretically justified warping. IJCV 67(2), 141–158 (2006)
Ranjan, A., Black, M.J.: Optical flow estimation using a spatial pyramid network. In: CVPR, pp. 4161–4170 (2017)
Revaud, J., Weinzaepfel, P., Harchaoui, Z., Schmid, C.: EpicFlow: edge-preserving interpolation of correspondences for optical flow. In: CVPR, pp. 1164–1172 (2015)
Rhemann, C., Hosni, A., Bleyer, M., Rother, C., Gelautz, M.: Fast cost-volume filtering for visual correspondence and beyond. In: CVPR, pp. 3017–3024 (2011)
Sun, D., Yang, X., Liu, M.Y., Kautz, J.: PWC-Net: CNNs for optical flow using pyramid, warping, and cost volume. In: CVPR, pp. 8934–8943 (2018)
Sun, D., Yang, X., Liu, M.Y., Kautz, J.: Models matter, so does training: an empirical study of CNNs for optical flow estimation. TPAMI (2019). https://doi.org/10.1109/TPAMI.2019.2894353
Werlberger, M., Trobin, W., Pock, T., Wedel, A., Cremers, D., Bischof, H.: Anisotropic Huber-L\(^{1}\) optical flow. In: BMVC (2009)
Xu, J., Ranftl, R., Koltun, V.: Accurate optical flow via direct cost volume processings. In: CVPR, pp. 1289–1297 (2017)
Yang, G., Ramanan, D.: Volumetric correspondence networks for optical flow. In: NeurIPS (2019)
Yin, Z., Darrell, T., Yu, F.: Hierarchical discrete distribution decomposition for match density estimation. In: CVPR, pp. 6044–6053 (2019)
Zimmer, H., Bruhn, A., Weickert, J.: Optic flow in harmony. IJCV 93(3), 368–388 (2011). https://doi.org/10.1007/s11263-011-0422-6
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Hui, TW., Loy, C.C. (2020). LiteFlowNet3: Resolving Correspondence Ambiguity for More Accurate Optical Flow Estimation. In: Vedaldi, A., Bischof, H., Brox, T., Frahm, JM. (eds) Computer Vision – ECCV 2020. ECCV 2020. Lecture Notes in Computer Science(), vol 12365. Springer, Cham. https://doi.org/10.1007/978-3-030-58565-5_11
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