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# SuperPoint

<div class="flex flex-wrap space-x-1">
<img alt="PyTorch" src="https://img.shields.io/badge/PyTorch-DE3412?style=flat&logo=pytorch&logoColor=white">
</div>

## Overview

The SuperPoint model was proposed
in [SuperPoint: Self-Supervised Interest Point Detection and Description](https://arxiv.org/abs/1712.07629) by Daniel
DeTone, Tomasz Malisiewicz and Andrew Rabinovich.

This model is the result of a self-supervised training of a fully-convolutional network for interest point detection and
description. The model is able to detect interest points that are repeatable under homographic transformations and
provide a descriptor for each point. The use of the model in its own is limited, but it can be used as a feature
extractor for other tasks such as homography estimation, image matching, etc.

The abstract from the paper is the following:

*This paper presents a self-supervised framework for training interest point detectors and descriptors suitable for a
large number of multiple-view geometry problems in computer vision. As opposed to patch-based neural networks, our
fully-convolutional model operates on full-sized images and jointly computes pixel-level interest point locations and
associated descriptors in one forward pass. We introduce Homographic Adaptation, a multi-scale, multi-homography
approach for boosting interest point detection repeatability and performing cross-domain adaptation (e.g.,
synthetic-to-real). Our model, when trained on the MS-COCO generic image dataset using Homographic Adaptation, is able
to repeatedly detect a much richer set of interest points than the initial pre-adapted deep model and any other
traditional corner detector. The final system gives rise to state-of-the-art homography estimation results on HPatches
when compared to LIFT, SIFT and ORB.*

<img src="https://huggingface.co/datasets/huggingface/documentation-images/resolve/main/transformers/model_doc/superpoint_architecture.png"
alt="drawing" width="500"/>

<small> SuperPoint overview. Taken from the <a href="https://arxiv.org/abs/1712.07629v4">original paper.</a> </small>

## Usage tips

Here is a quick example of using the model to detect interest points in an image:

```python
from transformers import AutoImageProcessor, SuperPointForKeypointDetection
import torch
from PIL import Image
import requests

url = "http://images.cocodataset.org/val2017/000000039769.jpg"
image = Image.open(requests.get(url, stream=True).raw)

processor = AutoImageProcessor.from_pretrained("magic-leap-community/superpoint")
model = SuperPointForKeypointDetection.from_pretrained("magic-leap-community/superpoint")

inputs = processor(image, return_tensors="pt")
outputs = model(**inputs)
```

The outputs contain the list of keypoint coordinates with their respective score and description (a 256-long vector).

You can also feed multiple images to the model. Due to the nature of SuperPoint, to output a dynamic number of keypoints,
you will need to use the mask attribute to retrieve the respective information :

```python
from transformers import AutoImageProcessor, SuperPointForKeypointDetection
import torch
from PIL import Image
import requests

url_image_1 = "http://images.cocodataset.org/val2017/000000039769.jpg"
image_1 = Image.open(requests.get(url_image_1, stream=True).raw)
url_image_2 = "http://images.cocodataset.org/test-stuff2017/000000000568.jpg"
image_2 = Image.open(requests.get(url_image_2, stream=True).raw)

images = [image_1, image_2]

processor = AutoImageProcessor.from_pretrained("magic-leap-community/superpoint")
model = SuperPointForKeypointDetection.from_pretrained("magic-leap-community/superpoint")

inputs = processor(images, return_tensors="pt")
outputs = model(**inputs)
image_sizes = [(image.height, image.width) for image in images]
outputs = processor.post_process_keypoint_detection(outputs, image_sizes)

for output in outputs:
    for keypoints, scores, descriptors in zip(output["keypoints"], output["scores"], output["descriptors"]):
        print(f"Keypoints: {keypoints}")
        print(f"Scores: {scores}")
        print(f"Descriptors: {descriptors}")
```

You can then print the keypoints on the image of your choice to visualize the result:
```python
import matplotlib.pyplot as plt

plt.axis("off")
plt.imshow(image_1)
plt.scatter(
    outputs[0]["keypoints"][:, 0],
    outputs[0]["keypoints"][:, 1],
    c=outputs[0]["scores"] * 100,
    s=outputs[0]["scores"] * 50,
    alpha=0.8
)
plt.savefig(f"output_image.png")
```
![image/png](https://cdn-uploads.huggingface.co/production/uploads/632885ba1558dac67c440aa8/ZtFmphEhx8tcbEQqOolyE.png)

This model was contributed by [stevenbucaille](https://huggingface.co/stevenbucaille).
The original code can be found [here](https://github.com/magicleap/SuperPointPretrainedNetwork).

## Resources

A list of official Hugging Face and community (indicated by 🌎) resources to help you get started with SuperPoint. If you're interested in submitting a resource to be included here, please feel free to open a Pull Request and we'll review it! The resource should ideally demonstrate something new instead of duplicating an existing resource.

- A notebook showcasing inference and visualization with SuperPoint can be found [here](https://github.com/NielsRogge/Transformers-Tutorials/blob/master/SuperPoint/Inference_with_SuperPoint_to_detect_interest_points_in_an_image.ipynb). 🌎

## SuperPointConfig

[[autodoc]] SuperPointConfig

## SuperPointImageProcessor

[[autodoc]] SuperPointImageProcessor

- preprocess
- post_process_keypoint_detection

## SuperPointForKeypointDetection

[[autodoc]] SuperPointForKeypointDetection

- forward
