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Labeling video assets

Two video-related project types exist in Kili:

  • Video (legacy)
  • Video

In Video (legacy) type projects, you will be able to perform classification and transcription tasks. You won't be able to upload videos (only outside hosting is allowed). To be able to upload videos and use advanced video labeling features like object tracking and label propagation, use a Video type project.


Labeling video in Video type projects

In Video type projects, videos are stored inside the Kili platform.
Kili Technology lets you decide if you want to import your data as native video files and annotate them as video or extract the video into a list of images and annotate them individually.
The labeling experience is very similar for both input types.



  • In case of native videos, the video is sampled into timestamps with the same duration. For example, if there are 24 sampled timestamps per second, annotation can be done for every 1/24th of a second of your video.
  • If you decided to break your video into frames, you will get a list of images and be able to annotate each one of them.

In a Video project, you can:


Creating annotations

When you create an annotation on an asset, an object is simultaneously created in the job viewer and on the timeline.
When you click on the annotation, the annotated object is selected in the job viewer and on the timeline.
The new annotation is automatically propagated to all the remaining frames of your video.
To deactivate automatic propagation, click on the Propagation button in the top-left toolbar.

To speed up your annotation process, Kili app can automatically track and annotate objects across multiple frames.
To turn on automatic tracking of your annotated objects click on the Tracking tool button in the top-left toolbar.

  • Tracking only works with the Bounding box tool tool.
  • By default, when activated, the tracking tool will classify an object on the current frame and all the following frames until the end of the video.
  • To classify an object on a specific range of frames, select the start frame, press and hold Shift, click on the end frame, and then classify the object.


Deleting annotations

When you delete an annotated object in a frame, it is deleted from the frame timeline and all the following frames.
The annotated object will still be visible in all the previous frames.

Grouping objects on multiple frames

You can use the Group feature to combine two or more objects in different frames. It is useful to link objects spanning different frames, for example objects that are temporarily masked in the video.
To merge two objects:

  1. Press and hold the Ctrl/Command keyboard button.
  2. Select the objects on the timeline.
  3. Using your mouse, right click on any of the objects and click the Group button (or press Ctrl/Command + G).

The grouped objects will have the same ID in the export labels.

Editing annotated objects

By default, when you edit an existing object on one frame, the change is automatically propagated to all the other frames.
To edit an object on one frame only, press the Propagation tool button in the top-left toolbar to deactivate it and make your change.
The frame will be turned into a "key frame" and marked with a padlock icon.

When modified, bounding box and point annotations are interpolated between the preceding key frame and the current key frame, as well as between the current key frame and the following key frame. If there are no preceding/following key frames, then there is no interpolation.