COCOJSON Extension Specification

• Title: COCOJSON
• Identifier: https://stac-extensions.github.io/cocojson/v1.0.0/schema.json
• Field Name Prefix: coco
• Scope: Item
• Extension Maturity Classification: Proposal
• Owner: @jamesfisher-geo

This document explains the COCOJSON Extension to the SpatioTemporal Asset Catalog (STAC) specification.

The COCOJSON format (Common Objects in Context JSON) is a standardized format used to represent object annotations along with metadata including segmentations masks, pixel bounding boxes, and annotation categories commonly used in computer vision. This extension integrates the standarized COCOJSON fields into the STAC Item spec, enabling a practitioner to embed COCOJSON annotations within STAC Items.

• Examples:
  • Item example: Shows the basic usage of the extension in a STAC Item
  • Collection example: Shows the basic usage of the extension in a STAC Collection
• JSON Schema
• Changelog

Fields

The fields in the table below can be used in these parts of STAC documents:

• Catalogs
• Collections
• Item Properties (incl. Summaries in Collections)
• Assets (for both Collections and Items, incl. Item Asset Definitions in Collections)
• Links

Field Name	Type	Description
coco:licenses	[License Object]	REQUIRED. Describe the required field...
coco:categories	[Category Object]	Describe the field...
coco:annotations	[Annotation Object]	Describe the field...

Additional Field Information

template:new_field

This is a much more detailed description of the field template:new_field...

License Object

This is the introduction for the purpose and the content of the XYZ Object...

Field Name	Type	Description
id	number	REQUIRED. Integer ID of the license
name	string	REQUIRED. License name
url	string	REQUIRED. URL to the license text

Category Object

This is the introduction for the purpose and the content of the XYZ Object...

Field Name	Type	Description
id	number	REQUIRED. Integer ID of the category
name	string	REQUIRED. Name of the category (e.g. 'cat')
supercategory	string	REQUIRED. General category (e.g. 'animal')

Annotation Object

This is the introduction for the purpose and the content of the XYZ Object...

Field Name	Type	Description
id	number	REQUIRED. Integer ID of the annotation
image_id	number	REQUIRED. Integer ID of the associated images from the 'coco:images' field
category_id	number	REQUIRED. Integer ID of the associated category from the 'coco:categories' field
bbox	/[number/]	REQUIRED. Bounding box of the annotation in pixel coordinates
segmentation	/[/[number, number/]/]	Segmentation mask of the annotation as a list of image coordinates
area	number	The area of the segmentation mask in pixels
iscrowd	bool	Tag indicating if the segmentation mask is of a single object or many objects in an image
score	number	Score 0 - 1.0 indicating the annotation confidence level

Contributing

All contributions are subject to the STAC Specification Code of Conduct. For contributions, please follow the STAC specification contributing guide Instructions for running tests are copied here for convenience.

Running tests

The same checks that run as checks on PR's are part of the repository and can be run locally to verify that changes are valid. To run tests locally, you'll need npm, which is a standard part of any node.js installation.

First you'll need to install everything with npm once. Just navigate to the root of this repository and on your command line run:

npm install

Then to check markdown formatting and test the examples against the JSON schema, you can run:

npm test

This will spit out the same texts that you see online, and you can then go and fix your markdown or examples.

If the tests reveal formatting problems with the examples, you can fix them with:

npm run format-examples