Labelbox documentation

Video

The Labelbox Editor contains specialized features for labeling video data. Watch the video above to learn some tips and tricks for labeling videos in Labelbox.

The labeling interface contains the following features when labeling video frames:

The Tools menu contains all of the object classes available in the ontology. For large ontologies, it can be useful to filter the object classes. You can do so by typing the object name in the search bar.

The Objects menu lists every annotation on the frame, including all object instances. For example, if there are two birds in the frame and you would like to create two instances of the "bird" object, you would 1) select the "bird" object from the Tools menu, 2) draw the annotation, then repeat those steps to create another instance.

The timeline shows the temporal progression of the video clip. You can hover over a frame in the timeline to preview it.

Drag the endpoints on the zoom bar to adjust the number of frames selected in the timeline. You can also drag the selection across the zoom bar to move to a different part in the timeline.

The following is not supported when labeling videos in the Editor:

  • Undo/redo actions

  • Change an existing annotation class

  • Text or dropdown classifications

How it works

There are three main components to creating and modifying video annotations in the Editor:

  • The selected frames to persist the annotation

  • The size of the annotation (only applies to bounding box)

  • The annotation position on the frame(s)

A keyframe is a frame on the timeline where a change occurs. Interpolated (tweened) frames the ones between two keyframes. Labelbox uses interpolation to incrementally adjust the size and position of annotation between keyframes. Note: interpolation is not applied to classifications.

By default, when you apply an annotation to a single frame, the annotation will persist until the last frame of the video.

bbox-single-frame.png

If you would rather limit an annotation to a set of frames, you must select the set of frames before applying the annotation to the frame selection.

bbox-frame-set.png

When you insert a new keyframe between two existing keyframes, Labelbox will re-interpolate the frames to adjust for the modified annotation on the newly inserted keyframe.

insert-bbox.png

When an object of interest exits the frame, then reappears 1 or more frames later, use the toggle icon to turn on/off the annotation. Toggle on/off annotations on multiple frames at a time is not supported. Note: Toggle on/off does not apply to classifications.

toggle-bbox.png

Use these shortcuts to quickly select frames on the timeline.

Shift+click

Select a set of consecutive frames on the timeline by clicking the first and last frame in the set.

Cmd/Ctrl+click

Select individual frames on the timeline.

Left/Right arrows

Seek the previous/next frame.

Shift+Left/Right arrows

Add the previous/next frame to the selection.