@datafire/openalpr

Client library for OpenALPR CarCheck API

Installation and Usage

npm install --save @datafire/openalpr

let openalpr = require('@datafire/openalpr').create();

.then(data => {
  console.log(data);
});

Description

The OpenALPR CarCheck API allows you to send images to the cloud for processing. The image will be analyzed for license plates and vehicle make/models. The results are returned in JSON format

Actions

getConfig

Get a list of available results for plate and vehicle recognition

openalpr.getConfig(null, context)

Input

This action has no parameters

Output

• output object
  • countries array
    • items object
      • code string
      • name string
  • vehicle_labels object
    • bodytype array
      • items string
    • color array
      • items string
    • make array
      • items string
    • makemodel array
      • items string
    • orientation array
      • items string
    • year array
      • items string

recognizeFile

Send an image for OpenALPR to analyze and provide metadata back The image is sent as a file using a form data POST

openalpr.recognizeFile({
  "image": "",
  "secret_key": "",
  "country": ""
}, context)

Input

• input object
  • image required string, object: The image file that you wish to analyze
    • content string
    • encoding string (values: ascii, utf8, utf16le, base64, binary, hex)
    • contentType string
    • filename string
  • secret_key required string: The secret key used to authenticate your account. You can view your
  • recognize_vehicle integer (values: 0, 1): If set to 1, the vehicle will also be recognized in the image
  • country required string: Defines the training data used by OpenALPR. "us" analyzes
  • return_image integer (values: 0, 1): If set to 1, the image you uploaded will be encoded in base64 and
  • topn integer: The number of results you would like to be returned for plate
  • is_cropped integer (values: 0, 1): When providing a plate or vehicle that is already cropped,

Output

• output object
  • credit_cost integer: The number of API credits that were used to process this image
  • credits_monthly_total integer: The maximum number of API credits available this month according to your plan
  • credits_monthly_used integer: The number of API credits used this month
  • data_type string (values: alpr_results, alpr_group, heartbeat): Specifies the type of data in this response
  • epoch_time number: Epoch time that the image was processed in milliseconds
  • img_height integer: Height of the input image in pixels
  • img_width integer: Width of the uploaded image in pixels
  • processing_time object
    • plates number: Time spent performing license plate recognition (in milliseconds)
    • total number: Time spent processing all tasks (in milliseconds)
    • vehicles number: Time spent performing vehicle recognition (in milliseconds)
  • regions_of_interest array: Describes the areas analyzed in the input image
    • items region_of_interest
  • results array
    • items plate_details
  • vehicles array: Describes all vehicles found in the input image
    • items vehicles
  • version integer: API format version

recognizeBytes

Send an image for OpenALPR to analyze and provide metadata back The image is sent as base64 encoded bytes.

openalpr.recognizeBytes({
  "image_bytes": "",
  "secret_key": "",
  "country": ""
}, context)

Input

• input object
  • image_bytes required string
  • secret_key required string: The secret key used to authenticate your account. You can view your
  • recognize_vehicle integer (values: 0, 1): If set to 1, the vehicle will also be recognized in the image
  • country required string: Defines the training data used by OpenALPR. "us" analyzes
  • return_image integer (values: 0, 1): If set to 1, the image you uploaded will be encoded in base64 and
  • topn integer: The number of results you would like to be returned for plate

Output

• output object
  • credit_cost integer: The number of API credits that were used to process this image
  • credits_monthly_total integer: The maximum number of API credits available this month according to your plan
  • credits_monthly_used integer: The number of API credits used this month
  • data_type string (values: alpr_results, alpr_group, heartbeat): Specifies the type of data in this response
  • epoch_time number: Epoch time that the image was processed in milliseconds
  • img_height integer: Height of the input image in pixels
  • img_width integer: Width of the uploaded image in pixels
  • processing_time object
    • plates number: Time spent performing license plate recognition (in milliseconds)
    • total number: Time spent processing all tasks (in milliseconds)
    • vehicles number: Time spent performing vehicle recognition (in milliseconds)
  • regions_of_interest array: Describes the areas analyzed in the input image
    • items region_of_interest
  • results array
    • items plate_details
  • vehicles array: Describes all vehicles found in the input image
    • items vehicles
  • version integer: API format version

recognizeUrl

Send an image for OpenALPR to analyze and provide metadata back The image is sent as a URL. The OpenALPR service will download the image and process it

openalpr.recognizeUrl({
  "image_url": "",
  "secret_key": "",
  "country": ""
}, context)

Input

• input object
  • image_url required string: A URL to an image that you wish to analyze
  • secret_key required string: The secret key used to authenticate your account. You can view your
  • recognize_vehicle integer (values: 0, 1): If set to 1, the vehicle will also be recognized in the image
  • country required string: Defines the training data used by OpenALPR. "us" analyzes
  • return_image integer (values: 0, 1): If set to 1, the image you uploaded will be encoded in base64 and
  • topn integer: The number of results you would like to be returned for plate

Output

• output object
  • credit_cost integer: The number of API credits that were used to process this image
  • credits_monthly_total integer: The maximum number of API credits available this month according to your plan
  • credits_monthly_used integer: The number of API credits used this month
  • data_type string (values: alpr_results, alpr_group, heartbeat): Specifies the type of data in this response
  • epoch_time number: Epoch time that the image was processed in milliseconds
  • img_height integer: Height of the input image in pixels
  • img_width integer: Width of the uploaded image in pixels
  • processing_time object
    • plates number: Time spent performing license plate recognition (in milliseconds)
    • total number: Time spent processing all tasks (in milliseconds)
    • vehicles number: Time spent performing vehicle recognition (in milliseconds)
  • regions_of_interest array: Describes the areas analyzed in the input image
    • items region_of_interest
  • results array
    • items plate_details
  • vehicles array: Describes all vehicles found in the input image
    • items vehicles
  • version integer: API format version

Definitions

coordinate

• coordinate object
  • x integer
  • y integer

plate_candidate

• plate_candidate object
  • confidence number: Confidence percentage that the plate number is correct
  • matches_template integer: Indicates whether the plate matched a regional text pattern
  • plate string: Plate number

plate_details

• plate_details object
  • candidates array: All the top N candidates that could be the correct plate number
    • items plate_candidate
  • confidence number: Confidence percentage that the plate number is correct
  • coordinates array: The X/Y coordinates of the license plate in the image
    • items coordinate
  • matches_template integer: Indicates whether the plate matched a regional text pattern
  • plate string: Best plate number for this plate
  • processing_time_ms number: Number of milliseconds to process the license plate
  • region string: Specified or detected region (e.g., tx for Texas)
  • region_confidence number: Confidence percentage that the plate region is correct
  • requested_topn integer: The max number of results requested
  • vehicle vehicle_details
  • vehicle_region region_of_interest

region_of_interest

• region_of_interest object
  • height integer
  • width integer
  • x integer
  • y integer

vehicle_candidate

• vehicle_candidate object
  • confidence number: confidence of value (percent)
  • name string: name of value

vehicle_details

• vehicle_details object
  • body_type array
    • items vehicle_candidate
  • color array
    • items vehicle_candidate
  • make array
    • items vehicle_candidate
  • make_model array
    • items vehicle_candidate
  • orientation array
    • items vehicle_candidate
  • year array
    • items vehicle_candidate

vehicles

• vehicles object
  • details vehicle_details
  • height integer
  • width integer
  • x integer
  • y integer