Head keypoints

Overview

The ground truth exposed in this modality is a set of 81 keypoints that define the overall shape of the head, using a standard developed by Datagen.

This modality consists of the following file:

Relevant file

Location

head_key_points.json

key_points folder

head_key_points.json

This file contains information on the structure of the subject’s head. It uses the following structure:

"version": "2.0.0",
"head": {
   "top": {
        // 12 keypoints defining the structure of the top of the head
   }
   "left": {
        // 24 keypoints defining the structure of the left side of the head
   }
   "back": {
        // 21 keypoints defining the structure of the back of the head
   }
   "right": {
        // 24 keypoints defining the structure of the right side of the head
   }
}

Note

For keypoints that define the structure of the front of the head, i.e., the face, see the iBug and MediaPipe facial keypoint modalities.

Objects and fields:

  • version: String. Version tracking for this file. Whenever you access this file in a datapoint, make sure to check that the version matches what you expect it to be; otherwise its format and fields may not be recognized.

  • top: Object. This object contains 12 objects, each identifying a specific keypoint on the top of the head. The keypoint objects are named “1” through “12”, and each one has the same format:

    "3": {
       "global_3d": {
          "x": 0.705421507358551,
          "y": 0.18709957599639893,
          "z": 0.044457197189331055
       },
       "pixel_2d": {
          "x": 212,
          "y": 851
       },
       "is_visible": "false"
    
    • global_3d: Object. Contains a set of three Floats giving the location of the keypoint in global coordinates: “x”, “y”, and “z”. See About our coordinate systems for details.

    • pixel_2d: Object. Contains a set of two Ints giving the x and y coordinates of the keypoint in the images produced by this camera. See About our coordinate systems for details.

    • is_visible: Boolean. Indicates whether the keypoint is visible in the images produced by this camera. The value of this field is false if the keypoint is outside the frame, is on the wrong side of the face, or is blocked from the camera’s view by another object. Otherwise the value is true.

    ../_images/top_of_head_labeled.png

    The 12 keypoints on the top of the head.

  • left: Object. This object has the same structure as “top” above, except it identifies 24 keypoints on the left side of the head.

    ../_images/left_of_head_labeled.png

    The 24 keypoints on the left side of the head.

  • back: Object. This object has the same structure as “top” above, except it identifies 21 keypoints on the left side of the head.

    ../_images/back_of_head_labeled.png

    The 21 keypoints on the back of the head.

  • right: Object. This object has the same structure as “top” above, except it identifies 24 keypoints on the left side of the head.

    ../_images/right_of_head_labeled.png

    The 24 keypoints on the right side of the head.