Detectors#

The detectors used in the CARS API subsystem are designed to detect vehicles and license plates (LP) in images, and also highlight the corresponding bounding boxes (BBox).

The configuration of the vehicle and license plate detectors is set in the configuration file /data/vehicleEngine.conf (see Appendix 2).

The testing of the detectors is available through the CARS API Tester interface (see «CARS Analytics. Administrator's Guide»).

Vehicle detector#

The vehicle detector is designed to detect vehicles in images and also provides information about the vehicle's position in a video stream or video file.

The latest version of the vehicle detector includes a re-detection algorithm for improved accuracy, the ability to work with images captured by cameras installed at significant heights (birdview), and the configuration of additional parameters for the vehicle detector.

An example of an input image is shown in Figure 27.

Example input image for Vehicle detector

Response example:

{
      "detections": [
        {
          "x": 637.8615112304688,
          "y": 161.5411834716797,
          "width": 426.82147216796875,
          "height": 274.2376708984375,
          "score": 0.9445058107376099
        },
        {
          "x": 115.89066314697266,
          "y": 155.4100341796875,
          "width": 476.1069030761719,
          "height": 282.51666259765625,
          "score": 0.9419910907745361
        }
      ],
      "detector": "car",
      "execution_time": 53
}

Table 34. Description of the fields in the Vehicle detector

Field name	Type	Description	Possible values
detections		An array containing the coordinates and size of the detections of each vehicle in the image, as well as an estimate of the accuracy of vehicle detection	List of detected vehicles
x	int	The horizontal coordinate of the upper left corner of the BBox	0…1920
y	int	The vertical coordinate of the top left corner of the BBox	0…1080
width	int	Bbox width	0…1920
height	int	Bbox height	0…1080
score	float	Estimation of vehicle detection accuracy	0.0000…1.0000
detector	string	The name of the detector type	car
execution_time	int	Execution time in milliseconds	0…1000

LP detector#

The license plate (LP) detector is designed to detect LPs in images and provides information about the position of the LP in a video stream or video file.

The latest version of the LP detector includes the ability to detect multiple plates on a single vehicle, as well as determine the relevant plate related to the correct vehicle. Additionally, the configuration of additional parameters for the LP detector is available.

An example of an input image is shown in Figure 28.

Response example:

{ "detections": [ { "x": 119.0, "y": 483.0,
"width": 156.0, "height": 97.0, "score": 0.93145 }, { "x": 112.0, "y": 533.0, "width": 137.0, "height": 88.0, "score": 0.82027 } ], "detector": "grz", "execution_time": 53 }

Table 35. Description of the LP detection fields

Field name	Type	Description	Possible values
detections		An array containing a list of all detected LPs on the image.	List of detected LPs.
x	int	The horizontal coordinate of the upper left corner of the BBox	0…1920
y	int	The vertical coordinate of the top left corner of the BBox	0…1080
width	int	Bbox width	0…1920
height	int	Bbox height	0…1080
score	float	Estimation of LPs detection accuracy	0.0000…1.0000
detector	string	The name of the detector type	grz
execution_time	int	Execution time in milliseconds	0…1000

Vehicle redetector#

The vehicle redetector is designed to detect vehicles in a specified region of the frame. This method allows returning the coordinates of the BBox of the vehicle found in the specified area of the image.

When using the vehicle redetector, you can send photos and detections for performing re-detection (redetection) of vehicles. The process includes uploading the image, preprocessing, and performing the redetection to improve accuracy. The redetector allows detecting multiple vehicles in a single frame and accurately determining their location. In case of errors or failed redetection attempts, the system returns an error description with the relevant details.

An example of an input image is shown in Figure 29.

Example input image for Vehicle redetector

Response example:

{
      "detections": [
        {
          "x": 162,
          "y": 103, 
          "width": 1072,
          "height": 749,
          "score": 0.6372541785240173
        }
      ],
      "execution_time": 20,
      "redetector": "car"
    }

Table 36. Description of the Vehicle Detection fields

Field name	Type	Description	Possible values
detections		An array containing the coordinates and size of each detected vehicle, as well as the detection accuracy score	List of detected vehicles
x	int	The horizontal coordinate of the upper left corner of the BBox	0…1920
y	int	The vertical coordinate of the top left corner of the BBox	0…1080
width	int	Bbox width	0…1920
height	int	Bbox height	0…1080
score	float	Accuracy score of the vehicle detection	0.0000…1.0000
redetector	string	The name of the redetector	car
execution_time	int	Execution time in milliseconds	0…1000

Smoke and/or fire detector#

The smoke and/or fire detector is designed to detect fires in images, video streams, and video files.

An example of an input image is shown in Figure 30.

Example input image for Smoke and/or fire detector

Response example:

{
    "detections": [
        {
            "x": 0,
            "y": 0,
            "width": 960,
            "height": 540,
            "score": 0.8205,
            "type": "fire"
        }
    ],
    "execution_time": 51,
    "detector": "smoke_fire"
}

Table 37. Description of the Smoke and/or fire detector fields

Field name	Type	Description	Possible values
detections		An array containing the coordinates, detection area size and the detections of fire or smoke in the image, as well as an estimate of the detection accuracy	List of detected zones
x	int	The horizontal coordinate of the upper left corner of the BBox	0…1920
y	int	The vertical coordinate of the top left corner of the BBox	0…1080
width	int	Width of detection zone	0…1920
height	int	Height of detection zone	0…1080
score	float	Estimation of smoke/fire detection accuracy	0.0000…1.0000
type	string	Type	- fire;
			- black_smoke;
			- white_smoke;
			- none - no fire
execution_time	int	Execution time in milliseconds	0…1000
detector	string	The name of the detector type	smoke_fire

Animal detector#

The animal detector is designed to detect animals in images, video streams, and video files.

An example of an input image is shown in Figure 31.

Response example:

{
    "detections": [
        {
            "x": 323,
            "y": 42,
            "width": 137,
            "height": 342,
            "score": 0.9622,
            "type": "big_animal"
        }
    ],
    "execution_time": 60,
    "detector": "animal"
}

Table 38. Description of the Animal detector fields

Field name	Type	Description	Possible values
detections		An array containing the coordinates and size of detections of each animal in the image, as well as an estimate of detection accuracy	List of detected animals
x	int	The horizontal coordinate of the upper left corner of the BBox	0…1920
y	int	The vertical coordinate of the top left corner of the BBox	0…1080
width	int	Bbox width	0…1920
height	int	Bbox height	0…1080
score	float	Estimation of animal detection accuracy	0.0000…1.0000
type	string	Type	- big_animal;
			- small_animal;
			- bird
execution_time	int	Execution time in milliseconds	0…1000
detector	string	The name of the detector type	animal

Detectors settings#

Detector settings allow you to retrieve the current parameters for vehicle and LP detectors, including detection accuracy thresholds and image sizes. The method returns the current settings for these detectors.

Response example:

{
  "detectorsSettings": [
    {
      "detector": "car",
      "scoreThreshold": 0.5,
      "imageSize": 640
    },
    {
      "detector": "grz",
      "scoreThreshold": 0.5,
      "imageSize": 220
    }
  ]
}

Table 39. Description of the detectors settings fields

Field name	Type	Description	Possible values
detectorsSettings	array	An array containing the current settings for VS and LP detectors	A list of objects with configuration parameters
detector	string	Type	car, grz
scoreThreshold	float	Detection accuracy threshold	0.0000…1.0000
imageSize	int	Image size for the detector	100…1280