# Some segmentation polygons are shifted after applying data augmentations

**URL:** https://discuss.roboflow.com/t/some-segmentation-polygons-are-shifted-after-applying-data-augmentations/3909
**Category:** 🤝  Community Help
**Tags:** bugs, segmentation
**Created:** [December 6, 2023, 2:39pm UTC](https://discuss.roboflow.com/t/some-segmentation-polygons-are-shifted-after-applying-data-augmentations/3909 "2023-12-06T14:39:31Z")
**Posts on this page:** 4
**Page:** 1

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### Author: ![gfx73](https://yyz1.discourse-cdn.com/flex029/user_avatar/discuss.roboflow.com/gfx73/32/2256_2.png) [@gfx73](https://discuss.roboflow.com/u/gfx73)
#### Post date: [December 6, 2023, 2:39pm UTC](https://discuss.roboflow.com/t/some-segmentation-polygons-are-shifted-after-applying-data-augmentations/3909/1 "2023-12-06T14:39:31Z")

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Hi. After applying augmentation I noticed that some segmentation masks in my dataset are shifted. What could I do with that?

My dataset is public and here is the link: [Sign in to Roboflow](https://app.roboflow.com/project-4nztg/barcodes-owxdn/2)

You can preview images in this specific version and find shifted masks. One example is the image with name " PostBarcode016.jpg".

Thank you for attention. I would really appreciate if you would help to figure out why this is happening

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### Author: ![leo](https://yyz1.discourse-cdn.com/flex029/user_avatar/discuss.roboflow.com/leo/32/2228_2.png) [@leo](https://discuss.roboflow.com/u/leo)
#### Post date: [December 7, 2023, 3:30am UTC](https://discuss.roboflow.com/t/some-segmentation-polygons-are-shifted-after-applying-data-augmentations/3909/2 "2023-12-07T03:30:39Z")

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Hi @gfx73

Sorry to hear you’re having issues. Let’s get that solved.

Could you please share your project’s Universe link? The address with `app.roboflow.com` is private. You can access your project’s Universe page by clicking the View on Universe link.  
 ![image](https://canada1.discourse-cdn.com/flex029/uploads/roboflow1/original/2X/8/8903bb72d3bd156f01ef486c9867a5da2b562efe.png)

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### Author: ![gfx73](https://yyz1.discourse-cdn.com/flex029/user_avatar/discuss.roboflow.com/gfx73/32/2256_2.png) [@gfx73](https://discuss.roboflow.com/u/gfx73)
#### Post date: [December 7, 2023, 10:49am UTC](https://discuss.roboflow.com/t/some-segmentation-polygons-are-shifted-after-applying-data-augmentations/3909/3 "2023-12-07T10:49:51Z")

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Hi @leo

After having a closer look it appears that the problem comes from “shear” augmentation. I have two versions of the dataset: with shear and without it. The difference is visible in images preview.

I hope this link is publicly available: [barcodes Instance Segmentation Dataset by project-4nztg](https://universe.roboflow.com/project-4nztg/barcodes-owxdn)

Thank you for your attention!

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### Author: ![system](https://canada1.discourse-cdn.com/flex029/uploads/roboflow1/original/1X/bb6edbfa56d0cf2ee603f061e9e09103502cc8cc.png) [@system](https://discuss.roboflow.com/u/system)
#### Post date: [December 28, 2023, 10:50am UTC](https://discuss.roboflow.com/t/some-segmentation-polygons-are-shifted-after-applying-data-augmentations/3909/4 "2023-12-28T10:50:04Z")

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