Papers › DocUNet: Document Image Unwarping via a Stacked U-Net

DocUNet: Document Image Unwarping via a Stacked U-Net

1 Jun 2018CVPR 2018 6archive 2025-07-28

Ke Ma, Zhixin Shu, Xue Bai, Jue Wang, Dimitris Samaras

Capturing document images is a common way for digitizing and recording physical documents due to the ubiquitousness of mobile cameras. To make text recognition easier, it is often desirable to digitally flatten a document image when the physical document sheet is folded or curved. In this paper, we develop the first learning-based method to achieve this goal. We propose a stacked U-Net with intermediate supervision to directly predict the forward mapping from a distorted image to its rectified version. Because large-scale real-world data with ground truth deformation is difficult to obtain, we create a synthetic dataset with approximately 100 thousand images by warping non-distorted document images. The network is trained on this dataset with various data augmentations to improve its generalization ability. We further create a comprehensive benchmark that covers various real-world conditions. We evaluate the proposed model quantitatively and qualitatively on the proposed benchmark, and compare it with previous non-learning-based methods.

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Code

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Tasks

Local DistortionMS-SSIMSSIM

Datasets

Introduced by this paper, per the archive.

DocUNet

Results from the paper archive 2025-07-28

TaskDatasetModelMetricValueRank at snapshotLeaderboardReport
Local Distortion DocUNet DocUNet LD 14.08 #5 of 5 Archive leaderboard report
MS-SSIM DocUNet DocUNet MS-SSIM 0.41 #4 of 4 Archive leaderboard report
SSIM DocUNet DocUNet SSIM 0.4083 #4 of 4 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

Concatenated Skip ConnectionConvolutionMax PoolingReLUU-Net

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