imageprocessing

Django project for REST API which manages sending, retrieving and processing of images.

The API follows the RFC6690 standard for Constrained RESTful Environments (CoRE) and is designed to receive, compress and then save image data into a database for performant file downloads by the API's clients. Supported payload formats are JSON as well as CBOR (Concise Binary Object Representation).

Prerequisites

• Up-to-date Python version (3.12 is recommended)
• PIP installation
• Virtual environment for setting up Python dependencies (optional)

Setup

1. Navigate into the project root (where manage.py and requirements.txt are located)
2. Install Python dependencies on your environment by running pip install -r requirements.txt
3. Run python manage.py runserver to start up the development server

The application should now run on your environment. The default port for Django applications is 8000.

For convenience an empty database setup is already included inside the SQLite file db.sqlite3 on project root level. If you encounter database problems consider removing the file and running python manage.py migrate afterwards.

Usage

For now the API only provides one resource type for an image collection with the semantic notation simple.act and the semantic interface type batch with the notation core.b. In accordance with the CoRE standard they can be discovered by sending following GET requests:

curl http://localhost:8000/.well-known/core
curl http://localhost:8000/collections

This will give you the following output:

</collections/images>;rt="simple.act";if="core.b"

For sending image data you can make a POST request to this resource link. The payload must contain values for the keys deviceId, timestamp and imageData. The value for imageData must consist of a base64 string encoding the file's binary content. timestamp must contain a valid ISO 8601 datetime representation. Valid payload formats are JSON and CBOR.

JSON Example

curl -d '{"deviceId":"12345", "timestamp":"2024-08-18T02:04:07Z", "imageData":"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"}' -H "Content-Type: application/json" -X POST http://localhost:8000/collections/images

CBOR Example

curl -d 'a36864657669636549646531323334356974696d657374616d7074323032342d30382d31385430323a30343a30375a69696d6167654461746179037c6956424f5277304b47676f414141414e535568455567414141425141414141554341494141414143363470614141414268476c445131424a51304d6763484a765a6d6c735a5141414b4a46396b543149773041637856395470555571676c5951636368516e537a3468546871465970514964514b7254715958506f46545271534642644877625867344d64693163484657566348563045512f414278646e4253644a45532f35635557735236634e7950642f6365642b38416f565a696d745578426d69366253626a4d54476457525544727769694633364d6f31396d6c6a456e53516d3048562f33385048314c73717a32702f376333537257597342507046346c686d6d54627842504c317047357a3369634f73494b76453538536a4a6c32512b4a4872697364766e504d75437a777a624b615338385268596a4866776b6f4c73344b70455538525231524e703377683762484b6559757a56717177786a333543304e5a6657575a367a5348454d63696c6942426849494b69696a42527052576e52514c5364715074664550756e364a58417135696d446b5745415a476d5458442f34487637753163704d54586c496f426e532b4f4d37484d42445942657056782f6b2b64707a364365422f42713730707239634132592b5361383274636752304c4d4e584677334e575550754e77424270344d325a526479553954794f5741397a503670677a516477743072586d394e665a782b67436b714b76454458427743497a6b4b5875397a62754472623339653662523377397272484b6b55444a705541414141416c7753466c7a41414175497741414c694d42654b552f646741414141643053553146422b674945674d7a4557412b484145414141415a6445565964454e766257316c626e514151334a6c5958526c5a4342336158526f4945644a54564258675134584141414168306c4551565134792b3154775133454941797a7135734939683868724f512b636b6f72494a7a61766b367158776b34646849424a6545754e6a7a416e785a7a65707074736255476f4e62364a5a6a5a744867454d7036724b4964375247426d5a6f617a6169632f477035564a4831572b794344696d7733552b6559596a456a5053487064783745466b73703055576f482b51756a336a7370544d346968646a5a304b536672797736483863486744664c336b4e4f33335177676b31414a41474141414141456c46546b5375516d4343' -H "Content-Type: application/cbor" -X POST http://localhost:8000/collections/images

After successfully sending the image you will get a confirmation in the form of a response with the status 201 and the newly created image's metadata as content.

For downloading an image file make a GET request to the resource link as following:

curl 'http://localhost:8000/collections/images?deviceId=12345&timestamp=2024-08-18T02%3A04%3A07Z' -o image.png

The GET parameters deviceId and timestamp are obligatory. timestamp must be properly URL-encoded. If the parameters are not provided or invalid you will get a 400 response. If they do not match an existing image you will get a 404 response.