Output JSON format

Labels in a 2D and a 3D project can be downloaded in a JSON file. Output JSON file consists of a labels array object, which has the following fields:

1. file_id (string): refers to the ID of the image/frame to which the label belongs to.

2. label_category_id (string): refers to the label category of the label.

3. label_id (string): refers to the ID of the label.

4. label_type (string): refers to the type of label created. It can have values of the following possible values with their corresponding description: a. box: this is a 2D bounding box label b. lane: this is a 2D lane label c. polygon: this is a 2D polygon label d. point: this is a 2D point label e. scene: this is a 2D scene label f. 3d_bbox: this is a 3D bounding box label g. 3d_point: this is a 3D point label h. 3d_polyline: this is a 3D polyline label i. 3d_polygon: this is a 3D polygon label j. scene: this is a 3D scene label

5. stage_id(string): refers to the stage of the label

6. attributes_source: refers to if attributes are added manually or automatically.

7. create_time_millis: refers to the time at which the label is created in milliseconds.

8. label_set_id: help multiple users to label the same object using their label set the id.

9. labeller_email: displays the labeller email.

10. sensor_id: displays the sensor id.

11. update_time_millis: refers to the last updated time at which a label is updated in milliseconds.

12. attributes (object): consists of the key-value pair for each label attribute.

13. box (array): An array of 4 numbers representing a 2D bounding box. The first two numbers refer to the x, y coordinates of the top left corner. The third and fourth number in the array refers to the length of the bounding box along the x and y axes respectively. This field is populated only when the label type is a box.

14. polygons (array): An array of polygons. Each polygon is an array of points. Each point is a 2-length array of x and y coordinates. This field is populated only when the label type is polygon or lane.

15. point (array): consists of coordinates of the point. This field is populated only when the label type is the point.

16. three_d_bbox (object): has the following fields: a. l (float): refers to the length of a 3D bounding box b. w (float): refers to the width of a 3D bounding box c. h (float): depicts the height of the 3D bounding box d. cx (float): refers to the x coordinate of the center of the 3D bounding box e. cy (float): refers to the y coordinate of the center of the 3D bounding box f. cz (float): refers to the z coordinate of the center of the 3D bounding box g. rot_z (float): depicts the angle (in radians) made by the front face of the 3D bounding box with the negative x-axis measured in the clockwise direction. h. quaternion: depicts the rotation angles of the box in quaternions. This field is populated only when the label type is 3d_bbox.

17. three_d_point_indices (array): consists of indices of LiDAR points in the point cloud file. This field is populated only when the label type is 3d_point.

18. three_d_polygon (array): is an array of x, y and z coordinates of different points comprising the polygon. This field is populated only when the label type is 3d_polygon.

19. three_d_polyline (object): has the following fields: a. polyline (array): consists of x, y and z coordinate values of the points creating polyline. b. polyline_width (float) : is the value of width of polyline. This field is populated only when the label type is 3d_polyline.