Open ALPR HTTP Wrapper

Just a small wrapper around the Open ALPR cli binary.

Simply send and HTTP Post of image data to /detect and get back JSON results from the attempted detection.

Installation

A docker image is available via:

docker pull sclaflin/open-alpr-http-wrapper

Docker Compose:

version: "3.9"
services:
  open-alpr-http-wrapper:
    container_name: open-alpr-http-wrapper
    restart: unless-stopped
    image: sclaflin/open-alpr-http-wrapper:latest
    ports:
      - "3000:3000"

Usage

Post image data to the /detect endpoint:

curl -F upload=@car0.png http://localhost:3000/detect

The following output is returned:

{
    "version": 2,
    "data_type": "alpr_results",
    "epoch_time": 1638566810336,
    "img_width": 1289,
    "img_height": 744,
    "processing_time_ms": 146.275497,
    "regions_of_interest": [],
    "results": [
        {
            "plate": "YZ88658",
            "confidence": 85.818779,
            "matches_template": 0,
            "plate_index": 0,
            "region": "",
            "region_confidence": 0,
            "processing_time_ms": 12.290022,
            "requested_topn": 10,
            "coordinates": [
                {
                    "x": 682,
                    "y": 342
                },
                {
                    "x": 805,
                    "y": 346
                },
                {
                    "x": 801,
                    "y": 400
                },
                {
                    "x": 680,
                    "y": 396
                }
            ],
            "candidates": [
                {
                    "plate": "YZ88658",
                    "confidence": 85.818779,
                    "matches_template": 0
                },
                {
                    "plate": "Y288658",
                    "confidence": 85.352005,
                    "matches_template": 0
                },
                {
                    "plate": "YZ8B658",
                    "confidence": 83.173759,
                    "matches_template": 0
                },
                {
                    "plate": "Y28B658",
                    "confidence": 82.706985,
                    "matches_template": 0
                },
                {
                    "plate": "YZ8865B",
                    "confidence": 78.087212,
                    "matches_template": 0
                }
            ]
        }
    ]
}

The root of the server also presents a form that you can use via web browser to upload and detect files.