Update Crello dataset card for LayerD paper and image segmentation task

This PR updates the `cyberagent/crello` dataset card to better reflect its use in the paper "[LayerD: Decomposing Raster Graphic Designs into Layers](https://huggingface.co/papers/2509.25134)".

Specifically, it:
- Updates `task_categories` in the metadata from `unconditional-image-generation` to `image-segmentation` to align with the LayerD paper's focus on decomposing images into layers.
- Introduces a new "Associated Projects and Papers" section under "Dataset Description" to clearly delineate the dataset's use in LayerD, including links to the paper, project page, and GitHub repository. The original CanvasVAE context is also explicitly detailed within this section.
- Adds a "Sample Usage (LayerD Data Preparation)" section with the code snippet from the LayerD GitHub README, demonstrating how to convert the Crello dataset for matting training.
- Updates the "Supported Tasks and Leaderboards" section to mention both the original task and the new image decomposition task.
- Adds the BibTeX citation for the LayerD paper in the "Citation Information" section, alongside the existing CanvasVAE citation.
- Corrects a minor formatting issue in the YAML metadata's `font` list to ensure valid structure.

README.md

@@ -13,7 +13,7 @@ size_categories:
 source_datasets:
 - original
 task_categories:
-- unconditional-image-generation
+- image-segmentation
 task_ids: []
 pretty_name: crello
 tags:
@@ -528,6 +528,11 @@ configs:
   - [Table of Contents](#table-of-contents)
   - [Dataset Description](#dataset-description)
     - [Dataset Summary](#dataset-summary)
+    - [Associated Projects and Papers](#associated-projects-and-papers)
+      - [LayerD: Decomposing Raster Graphic Designs into Layers](#layerd-decomposing-raster-graphic-designs-into-layers)
+      - [CanvasVAE: Learning to Generate Vector Graphic Documents (Original Context)](#canvasvae-learning-to-generate-vector-graphic-documents-original-context)
+    - [Usage (Loading the dataset)](#usage-loading-the-dataset)
+    - [Sample Usage (LayerD Data Preparation)](#sample-usage-layerd-data-preparation)
     - [Supported Tasks and Leaderboards](#supported-tasks-and-leaderboards)
     - [Languages](#languages)
   - [Dataset Structure](#dataset-structure)
@@ -552,17 +557,22 @@ configs:
 
 ## Dataset Description
 
-- **Homepage:** [CanvasVAE github](https://github.com/CyberAgentAILab/canvas-vae)
-- **Repository:**
-- **Paper:** [CanvasVAE: Learning to Generate Vector Graphic Documents](https://arxiv.org/abs/2108.01249)
-- **Leaderboard:**
-- **Point of Contact:** [Kota Yamaguchi](https://github.com/kyamagu)
+The Crello dataset is a collection of raster graphic designs originally compiled for the study of vector graphic documents. It contains document meta-data such as canvas size and pre-rendered elements such as images or text boxes. The original templates were collected from [crello.com](https://crello.com) (now [create.vista.com](https://create.vista.com/)) and converted to a low-resolution format suitable for machine learning analysis. More recently, it has been used for research into decomposing raster graphic designs into layers, as presented in the LayerD paper.
 
-### Dataset Summary
+### Associated Projects and Papers
 
-The Crello dataset is compiled for the study of vector graphic documents. The dataset contains document meta-data such as canvas size and pre-rendered elements such as images or text boxes. The original templates were collected from [crello.com](https://crello.com) (now [create.vista.com](https://create.vista.com/)) and converted to a low-resolution format suitable for machine learning analysis.
+#### LayerD: Decomposing Raster Graphic Designs into Layers
+- **Paper:** [LayerD: Decomposing Raster Graphic Designs into Layers](https://huggingface.co/papers/2509.25134)
+- **Project Page:** https://cyberagentailab.github.io/LayerD/
+- **Repository:** https://github.com/CyberAgentAILab/LayerD
+- **Point of Contact:** [Tomoyuki Suzuki](https://tomoyukun.github.io/biography/), Kang-Jun Liu, [Naoto Inoue](https://naoto0804.github.io/), [Kota Yamaguchi](https://sites.google.com/view/kyamagu)
 
-### Usage
+#### CanvasVAE: Learning to Generate Vector Graphic Documents (Original Context)
+- **Paper:** [CanvasVAE: Learning to Generate Vector Graphic Documents](https://arxiv.org/abs/2108.01249)
+- **Homepage:** [CanvasVAE github](https://github.com/CyberAgentAILab/canvas-vae)
+- **Point of Contact:** [Kota Yamaguchi](https://github.com/kyamagu)
+
+### Usage (Loading the dataset)
 
 ```python
 import datasets
@@ -570,9 +580,20 @@ import datasets
 dataset = datasets.load_dataset("cyberagent/crello", revision="5.0.0")
 ```
 
+### Sample Usage (LayerD Data Preparation)
+
+The LayerD project, which uses this dataset for training its top-layer matting module, provides a script to prepare the Crello dataset. You can convert the Crello dataset for this purpose using the following command from the LayerD repository:
+
+```bash
+uv run python ./tools/generate_crello_matting.py --output-dir </path/to/dataset> --inpainting --save-layers
+```
+
+> [!NOTE]
+> This script downloads [the Crello dataset](https://huggingface.co/datasets/cyberagent/crello) (<20GB) from Hugging Face. Please ensure you have a stable internet connection and sufficient disk space for the first run.
+
 ### Supported Tasks and Leaderboards
 
-[CanvasVAE](https://arxiv.org/abs/2108.01249) studies unsupervised document generation.
+The Crello dataset supports unsupervised document generation (as studied by CanvasVAE) and layer decomposition / image segmentation (as studied by LayerD).
 
 ### Languages
 
@@ -601,54 +622,56 @@ In the following, categorical fields are shown as `categorical` type, but the ac
 
 **Canvas attributes**
 
-| Field         | Type        | Shape   | Description                                                     |
-| ------------- | ----------- | ------- | --------------------------------------------------------------- |
-| id            | string      | ()      | Template ID from create.vista.com                               |
-| group         | categorical | ()      | Broad design groups, such as social media posts or blog headers |
-| format        | categorical | ()      | Detailed design formats, such as Instagram post or postcard     |
-| category      | categorical | ()      | Topic category of the design, such as holiday celebration       |
-| canvas_width  | int64       | ()      | Canvas pixel width                                              |
-| canvas_height | int64       | ()      | Canvas pixel height                                             |
-| length        | int64       | ()      | Length of elements                                              |
-| suitability   | categorical | (None,) | List of display tags, only `mobile` tag exists                  |
-| keywords      | string      | (None,) | List of keywords associated to this template                    |
-| industries    | categorical | (None,) | List of industry tags like `marketingAds`                       |
-| preview       | image       | ()      | Preview image of the template for convenience                   |
-| cluster_index | int64       | ()      | Cluster index used to split the dataset; only for debugging     |
+| Field | Type | Shape | Description |
+| :------------ | :---------- | :------ | :-------------------------------------------------------------- |
+| id | string | () | Template ID from create.vista.com |
+| group | categorical | () | Broad design groups, such as social media posts or blog headers |
+| format | categorical | () | Detailed design formats, such as Instagram post or postcard |
+| category | categorical | () | Topic category of the design, such as holiday celebration |
+| canvas_width | int64 | () | Canvas pixel width |
+| canvas_height | int64 | () | Canvas pixel height |
+| length | int64 | () | Length of elements |
+| suitability | categorical | (None,) | List of display tags, only `mobile` tag exists |
+| keywords | string | (None,) | List of keywords associated to this template |
+| industries | categorical | (None,) | List of industry tags like `marketingAds` |
+| preview | image | () | Preview image of the template for convenience |
+| cluster_index | int64 | () | Cluster index used to split the dataset; only for debugging |
 
 **Element attributes**
 
-| Field          | Type        | Shape        | Description                                                      |
-| -------------- | ----------- | ------------ | ---------------------------------------------------------------- |
-| type           | categorical | (None,)      | Element type, such as vector shape, image, or text               |
-| left           | float32     | (None,)      | Element left position                                            |
-| top            | float32     | (None,)      | Element top position                                             |
-| width          | float32     | (None,)      | Element width                                                    |
-| height         | float32     | (None,)      | Element height                                                   |
-| color          | string      | (None, None) | RGB color palette of the vector graphic element                  |
-| opacity        | float32     | (None,)      | Opacity in [0, 1] range                                          |
-| image          | image       | (None,)      | Pre-rendered preview of the element encoded in PNG format        |
-| text           | string      | (None,)      | Text content in UTF-8 encoding for text element                  |
-| font           | categorical | (None,)      | Font family name for text element                                |
-| font_size      | float32     | (None,)      | Font size (height) in pixels                                     |
-| text_align     | categorical | (None,)      | Horizontal text alignment, left, center, right for text element  |
-| angle          | float32     | (None,)      | Element rotation angle (degree) w.r.t. the center of the element |
-| font_bold      | boolean     | (None, None) | Character-wise flag to indicate bold font                        |
-| font_italic    | boolean     | (None, None) | Character-wise flag to indicate italic font                      |
-| text_color     | string      | (None, None) | Character-wise rgba color                                        |
-| text_line      | int64       | (None, None) | Character-wise index of line number                              |
-| capitalize     | boolean     | (None,)      | Binary flag to capitalize letters                                |
-| line_height    | float32     | (None,)      | Scaling parameter to line height, default is 1.0                 |
-| letter_spacing | float32     | (None,)      | Adjustment parameter for letter spacing, default is 0.0          |
+| Field | Type | Shape | Description |
+| :------------ | :---------- | :----------- | :--------------------------------------------------------------- |
+| type | categorical | (None,) | Element type, such as vector shape, image, or text |
+| left | float32 | (None,) | Element left position |
+| top | float32 | (None,) | Element top position |
+| width | float32 | (None,) | Element width |
+| height | float32 | (None,) | Element height |
+| color | string | (None, None) | RGB color palette of the vector graphic element |
+| opacity | float32 | (None,) | Opacity in [0, 1] range |
+| image | image | (None,) | Pre-rendered preview of the element encoded in PNG format |
+| text | string | (None,) | Text content in UTF-8 encoding for text element |
+| font | categorical | (None,) | Font family name for text element |
+| font_size | float32 | (None,) | Font size (height) in pixels |
+| text_align | categorical | (None,) | Horizontal text alignment, left, center, right for text element |
+| angle | float32 | (None,) | Element rotation angle (degree) w.r.t. the center of the element |
+| font_bold | boolean | (None, None) | Character-wise flag to indicate bold font |
+| font_italic | boolean | (None, None) | Character-wise flag to indicate italic font |
+| text_color | string | (None, None) | Character-wise rgba color |
+| text_line | int64 | (None, None) | Character-wise index of line number |
+| capitalize | boolean | (None,) | Binary flag to capitalize letters |
+| line_height | float32 | (None,) | Scaling parameter to line height, default is 1.0 |
+| letter_spacing | float32 | (None,) | Adjustment parameter for letter spacing, default is 0.0 |
 
 `left` and `top` can be negative because elements can be bigger than the canvas size.
 `text_line` indicates the index of the text line.
 For example, the following indicates that `Be` is in the first line and the rest in the next line.
-The newline character `\n` if present is ignored in rendering.
+The newline character `
+` if present is ignored in rendering.
 
 ```
 {
-  "text": "Be\nambitious!",
+  "text": "Be
+ambitious!",
   "text_line": [0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1],
 }
 ```
@@ -737,6 +760,17 @@ We do not re-distribute the original files as we are not allowed by terms.
       year={2021}
     }
 
+If you use the Crello dataset in work related to layer decomposition or the LayerD project, please also cite:
+
+```bibtex
+@inproceedings{suzuki2025layerd,
+  title={LayerD: Decomposing Raster Graphic Designs into Layers},
+  author={Suzuki, Tomoyuki and Liu, Kang-Jun and Inoue, Naoto and Yamaguchi, Kota},
+  booktitle={ICCV},
+  year={2025}
+}
+```
+
 ### Releases
 
 5.1.0: v5.1 release (Oct 31, 2024)
@@ -780,7 +814,6 @@ We do not re-distribute the original files as we are not allowed by terms.
 
 1.0: v1 release (Aug 24, 2021)
 
-
 ### Contributions
 
 Thanks to [@kyamagu](https://github.com/kyamagu) for adding this dataset.