Papers › CRAFT: Cross-Attentional Flow Transformer for Robust Optical Flow

CRAFT: Cross-Attentional Flow Transformer for Robust Optical Flow

31 Mar 2022CVPR 2022 1arXiv:2203.16896archive 2025-07-28

Xiuchao Sui, Shaohua Li, Xue Geng, Yan Wu, Xinxing Xu, Yong liu, Rick Goh, Hongyuan Zhu

Optical flow estimation aims to find the 2D motion field by identifying corresponding pixels between two images. Despite the tremendous progress of deep learning-based optical flow methods, it remains a challenge to accurately estimate large displacements with motion blur. This is mainly because the correlation volume, the basis of pixel matching, is computed as the dot product of the convolutional features of the two images. The locality of convolutional features makes the computed correlations susceptible to various noises. On large displacements with motion blur, noisy correlations could cause severe errors in the estimated flow. To overcome this challenge, we propose a new architecture "CRoss-Attentional Flow Transformer" (CRAFT), aiming to revitalize the correlation volume computation. In CRAFT, a Semantic Smoothing Transformer layer transforms the features of one frame, making them more global and semantically stable. In addition, the dot-product correlations are replaced with transformer Cross-Frame Attention. This layer filters out feature noises through the Query and Key projections, and computes more accurate correlations. On Sintel (Final) and KITTI (foreground) benchmarks, CRAFT has achieved new state-of-the-art performance. Moreover, to test the robustness of different models on large motions, we designed an image shifting attack that shifts input images to generate large artificial motions. Under this attack, CRAFT performs much more robustly than two representative methods, RAFT and GMA. The code of CRAFT is is available at https://github.com/askerlee/craft.

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SETransInitWeights askerlee/craft/core/setrans.py official repository ran · metamorphic tier: deterministic WTFPL · pointer only · e813ff65ee2974d5 · report
CrossAttFeatTrans askerlee/craft/core/setrans.py official repository unverified WTFPL · pointer only · 8eb6a5653d8e8863 · report
ExpandedFeatTrans askerlee/craft/core/setrans.py official repository unverified WTFPL · pointer only · a23df79019522512 · report
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Tasks

Optical Flow Estimation

Results from the paper archive 2025-07-28

TaskDatasetModelMetricValueRank at snapshotLeaderboardReport
Optical Flow Estimation KITTI 2015 (train) CRAFT EPE 4.88 #11 of 19 Archive leaderboard report
Optical Flow Estimation KITTI 2015 (train) CRAFT F1-all 17.5 #11 of 19 Archive leaderboard report

Ranks are positions in the archive's leaderboards as they stood at the 2025-07-28 snapshot. Results published since then are not among these rows, so a rank here is not a current standing.

Methods

Absolute Position EncodingsAdamAttentionBPEDense ConnectionsDropoutLabel SmoothingLayer NormalizationLinear LayerMulti-Head AttentionPosition-Wise Feed-Forward LayerResidual ConnectionSoftmaxTransformer

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