Add dataset card, link to paper and code

Hi! I'm Niels, part of the community science team at Hugging Face. I'm opening this PR to improve the dataset card for RealAlign.

This PR adds:
- Relevant metadata (`task_categories: text-to-image`).
- Links to the associated paper, project page, and GitHub repository.
- A summary of the dataset's purpose and the curation pipeline used to generate the preference pairs.

README.md

@@ -1,3 +1,41 @@
 ---
 license: cc-by-4.0
+task_categories:
+- text-to-image
 ---
+
+# RealAlign Dataset
+
+[**Project Page**](https://cwyxx.github.io/RealAlign) | [**Paper**](https://huggingface.co/papers/2605.19839) | [**Code**](https://github.com/Cwyxx/RealAlign)
+
+This dataset is part of the **RealAlign** project, introduced in the paper "[When Preference Labels Fall Short: Aligning Diffusion Models from Real Data](https://huggingface.co/papers/2605.19839)".
+
+## Dataset Summary
+
+RealAlign investigates whether real data can serve as an alternative source of supervision for preference alignment in diffusion models. Instead of relying on manually annotated preference pairs from model-generated images, this dataset treats real images as reference points and constructs preference signals by contrasting them with generated or perturbed samples.
+
+The repository contains curated `(real, fake)` preference pairs derived from:
+- **HPDv3**
+- **Pick-a-Pic v2**
+- **Civitai-top**
+
+## Data Curation Pipeline
+
+The dataset was built using a four-stage curation pipeline:
+1. **Extract**: Initial data collection from source distributions.
+2. **Construct Pairs**: Creating pairings between real images and model-generated or perturbed samples.
+3. **Score**: Applying automated scoring to evaluate the pairs.
+4. **Filter**: Final selection of high-quality preference signals to produce the training CSV.
+
+These curated pairs are used to align diffusion models like Stable Diffusion 1.5 and Stable Diffusion 3.5 Medium through a two-stage training process involving Diffusion-DRO (Inverse RL) and Diffusion-DPO.
+
+## Citation
+
+```bibtex
+@article{realalign2024,
+  title={When Preference Labels Fall Short: Aligning Diffusion Models from Real Data},
+  author={Zhou, Yifan and others},
+  journal={arXiv preprint arXiv:2605.19839},
+  year={2024}
+}
+```