> ## Documentation Index
> Fetch the complete documentation index at: https://docs.encord.com/llms.txt
> Use this file to discover all available pages before exploring further.
# COCO Format Export
If using Windows, we recommend using [7-Zip](https://www.7-zip.org/) to unzip the exported labels.
COCO export is not available for PCD scenes.
All coordinates in the COCO format correspond directly to pixel values. Refer to the [COCO documentation](https://cocodataset.org/#home) for details on the COCO format.
The export contains a list of JSON objects, with each JSON object representing a single data unit and containing detailed information for all exported labels.
The example below describes all the keys for a single exported data unit.
| **Key** | **Description** | **Notes** |
| ------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `annotations` | Contains all label information | |
| `area` | The area contained by the label | in units of square pixels |
| `attributes` | A list of attributes belonging to a label | |
| `classifications` | All radio and checklist attributes and their answers | |
| `#relation` | The hash of the ontology object the label is related to | The hash is the object's unique identifier |
| `encord_track_uuid` | A unique identifier for the object instance | The same as the `objectHash` in a JSON export. |
| `manual_annotation` | Indicates whether the annotation was created manually. | `True` is the annotation is manual, `False` if created using automated labeling techniques |
| `track_id` | The unique identifier for the instance the label is associated with | The value is the same for all annotations belonging to the same instance |
| `bbox` | Pixel coordinates for the top-left corner of a bounding box that encloses the label. This is provided for all shape types. | |
| `category_id` | A numerical ID linking this annotation to a field in the `categories` list containing Ontology information. | For example, the `category_id` value `1` in an annotation links it to the corresponding Ontology shape with the ID `1` in the `categories` field of the export. |
| `id` | The unique identifier for the label | Each label has a unique identifier, irrespective of which instance it is associated with |
| `image_id` | The ID of the image or frame the label is on | For example, ID `0` indicates that the label is on the first image in the `images` list of the export |
| `iscrowd` | The `iscrowd` field specifies whether the annotation represents a single object (`iscrowd=0`, using polygons) or a collection of objects (`iscrowd=1`, using RLE). Single objects may require multiple polygons if occluded, while crowd annotations are used for large groups of objects (e.g., a crowd of people) | |
| `keypoints` | The keypoints field is a list of coordinates and visibility flags for specific points on an object | |
| `num_keypoints` | The num\_keypoints field indicates the number of labeled keypoints (v > 0) for an object. Objects without labeled keypoints (e.g., small or crowd objects) have num\_keypoints=0 | Keypoints and their connections (skeletons) are defined in the categories section, which includes the names and connectivity of the keypoints for visualization |
| `segmentation` | Contains the (x,y) pixel coordinates for all label vertices | |
| `categories` | Contains Ontology information | |
| `name` | The object's name in the Ontology | |
| `supercategory` | The name of the object's class | |
| `keypoints` | `keypoint` for keypoint labels. Omitted for all other labels | |
| `skeleton` | Defines connectivity via a list of keypoint edge pairs and is used for visualization | |
| `images` | Contains file information for all modalities | |
| `coco_url` | URL to the file if it is hosted on the COCO dataset’s official servers | Only meaningful when working with the official COCO tasks. In all other cases the `coco_url` field is empty. |
| `file_name` | The name of the file | |
| `height` | The height of the image or frame | Measured in pixels |
| `image_title` | The title of the file | |
| `width` | The width of the image or frame | Measured in pixels |
| `info` | Contains additional information | |