Video Annotation

Detailed guide on how to quickly annotate videos using automatic interpolation.

All tools available for Image annotation are also available in video annotation. You can use Bounding box, Polygon, Polyline, Keypoint and Cuboid tools to label your objects. You can also create issues, navigate between frames, or switch between Object Detection, Classification and Attribute annotation modes.

Video Annotation workspace In the annotation workspace, you can see a video player at the bottom of the screen. The player contains a seek bar, video player controls, and a couple of other features as explained below.

Skip step This is the number of frames that the skip forward or skip backward buttons on either side of the play button, will skip. So if you have 20 set as the skip step, when you press the skip forward button, you will move 20 frames forward. To move a single frame backward or forward use the navigation buttons at the top.

Track Objects This switch allows you track an object across the video. In a track, labels on different frames are marked as belonging to the same object moving through the video. When the switch is turned on, any object you label will be labeled in track mode.

In this mode, the object sidebar shows a slightly different object card, as can be seen in the image above. You can move between different frames that the object track is in, using buttons in this card.

Automatic annotation

When the track mode is turned on, you don't need to mark labels of an object in every frame. For example, you could mark the object in the current frame, then skip forward 20 steps → Adjust the label to the current frame. All intermediate frames are automatically adjusted. If you find some frames are not labeled properly, adjust them on a frame, and again the rest will be adjusted according to the new changes.

When the track is finished (object goes out of view), mark the track's end by clicking on the End track (first button in the object card in the right sidebar) button. This will stop propagating the labels in subsequent frames.