This page is for version 3.3.0 (default).
For other versions, use one of these documentation indexes:
- 3.3.0 (default): https://docs.nvidia.com/vss/3.3.0/llms.txt
- Dev: https://docs.nvidia.com/vss/dev/llms.txt
The JSON schema definition for calibration is as follows:
The core sensor specific parameters are under the sensors section.
It includes the parameters for coordinates transformation between pixel domain and global coordinate system
as well as other meta info used for various applications. A brief description of the parameters is as follows:
| Parameter | Description |
|---|---|
| type | String identifier for the sensor type |
| id | Unique string identifier for the sensor |
| origin | Geographic coordinates (latitude/longitude) defining the sensor’s origin point |
| geoLocation | Geographic coordinates (latitude/longitude) specifying the sensor’s physical location |
| coordinates | Cartesian coordinates (x,y,z) of the sensor in local space, z is optional |
| translationToGlobalCoordinates | Translation vector (x,y,z) to convert between global coordinates and floor plan map, z is optional. This is used when the origin is not matched between floor plan map and global coordinate system. This field is mainly used in pair with scaleFactor in our simulation-based calibration. |
| scaleFactor | Numerical factor for scaling between global coordinates and floor plan map. This is used when the scale is not matched between floor plan map and global coordinate system. This field is mainly used in pair with translationToGlobalCoordinates in our simulation-based calibration. |
| attributes | Array of name-value pairs for additional sensor attributes |
| group | Group configuration including name, type, origin coordinates, and dimensions |
| region | Region definition with place level, origin coordinates, and dimensions |
| place | Array of name-value pairs defining the sensor’s location hierarchy |
| imageCoordinates | Array of 2D points (x,y) in image space. This is used in pair with globalCoordinates as the core calibration properties to define the transformation between image space and global coordinate space. |
| globalCoordinates | Array of points (x,y,z) in global coordinate space, z is optional. This is used in pair with imageCoordinates as the core calibration properties to define the transformation between image space and global coordinate space. |
| intrinsicMatrix | 3x3 camera intrinsic parameter matrix. This is used for 3D workflows. Our simulation-based calibration can generate this matrix or you can find it for any camera following the instructions in our manual calibration guide. |
| extrinsicMatrix | 3x4 camera extrinsic parameter matrix. This is used for 3D workflows. Our simulation-based calibration can generate this matrix or you can find it for any camera following the instructions in our manual calibration guide. |
| cameraMatrix | 3x4 combined camera projection matrix. This is the camera projection matrix which is the combination of intrinsic and extrinsic matrices. Our simulation-based calibration can generate this matrix or you can find it for any camera following the instructions in our manual calibration guide. It is optional. |
| homography | 3x3 homography transformation matrix. This is a derived matrix from intrinsicMatrix and extrinsicMatrix. It is optional. |
| ROIs | Array of regions of interest with coordinates and object type restrictions. This is used for ROI related events and safety alerts. ROIs defined here are in global coordinate system and are sensor specific. User can define non-sensor specific (global) ROIs as well outside of sensors section as defined in the JSON schema above. |
| tripwires | Array of tripwire definitions with wire coordinates and direction vectors. This is used for tripwire related events and safety alerts. Tripwires defined here are in global coordinate system and are sensor specific. tripwire.wire supports polyline, and additional segments can be created by simply adding more points (e.g. p3, p4, and so on). tripwire.direction defines the crossing orientation as a vector from p1 to p2, where p1 is the IN (inside) point and p2 is the OUT (outside) point. See Event Detection in behavior-analytics for details. User can define non-sensor specific (global) tripwires as well outside of sensors section as defined in the JSON schema above. |