Stabilizing Video Clips

Video stabilization smooths out undesired picture movements by negating inadvertent movements in the image. This produces unusable edges in the footage that are cropped off automatically by zooming into the picture. The result: A more stable picture at a nearly imperceptibly increased zoom level.

  1. You can use the video stabilization either as a Media FX or as an Event FX.

    • When using as a Media FX:

      In the Project Media window, select the video you want to stabilize.

      TIP Ifyou're using only a portion of a longer media file, you can use the Trimmer window to create a sub-clip that containsonly the portion of the media that is used in your project. Stabilizinga sub-clip requires less processing than stabilizing a full media file. For more information, see Using the Trimmer

      From the Tools menu, choose Video, and then choose Media FX (or right-click a media file in the Project Media window and choose Media FX from the shortcut menu). The Plug-In Chooser is displayed.

      TIP You can access the Media FX also via the More button of a video event, where you also can add a button for it in the event header. The Media FX button in the header also functions as an indicator, whether a Media FX is applied () or not ().

    • When using as an Event FX: Click the Event FX button at the event. The Plug-In Chooser is displayed.

  2. In the Plug-In Chooser, select the Video Stabilization plug-in and click the Add button. The Media FX dialog displays the Video Stabilization plug-in.

Video stabilization can work in three different complexity levels. Switch between these levels with the User view drop-down list. In the initial Basic view there are few controls and most everything works automatically. If you don't get the results you want in Basic mode, click the Reset button and switch to either Professional or Expert mode to try again..

Here we proceed to explain the controls that are revealed when you chose the Professional mode. The Expert view has even more controls which are covered at the end of this section.

  1. In the Parameters section:

    • Choose either Fast or Accurate mode from the drop-down menu to specify whether you want faster or more accurate analysis.

    • With Motion Compensation you chose which kind of motion in the video is taken into account when analyzing the motion compensation.

  2. Click Analyze Motion to start the analysis. The process will take some time depending upon the chosen mode, the length of the file, and other factors. When the analysis is complete, the stabilization is automatically applied to your media.

    NOTE You cannot change the method of the analysis without doing the analysis again. For this, click Clear Motion Data to discard the motion analysis, make your changes and run the analysis again.

  3. Start the playback of the clip and check the result of the stabilization. Perform any necessary adjustments in the Stabilization options and Borders section parameters.

    There are two different modes of stabilization available, Smooth motion and Freeze motion

    Smoothing The camera movement always consists of many small, fast, and unintentional movements and shaking, along with any intentional movements like pans, zooms or travel that must be kept. Smoothing is the parameter that helps to define how much "unsteadiness" should be kept in a scene, the higher that factor is, the more the movements are smoothed.

    Freeze motion In the Freeze motion mode it is assumed that there was no intended camera movement at all in the scene. Select one frame of the video with the Reference Frame Number slider that defines the reference view that should be kept. All other frames before and after this frame will be transformed according to the detected motion to keep this view.

    Borders: When the picture is moved in one direction to compensate for an unintended camera movement black borders will appear at the opposite edge. To avoid this, the picture is zoomed by a certain amount that is set by the Additional Zoom factor. An optimal value for Additional Zoom is calculated when the Auto Zoom box is checked, but you can freely change this value to keep as much image information as possible. You can further fine tune this with the Additional Rotation and Additional Translation parameters. Keep in mind that these parameters are automatable, so you can apply these corrections only where they are necessary.

    Edge Filling: For the cases where borders cannot be avoided, you can define how these borders are filled to make the zoom as unnoticeable as possible:

    • Transparent: Results in black borders (or video from the track below showing through).
    • Mirror padding: The video content is mirrored at the edge.
    • Repeat: The video content is repeated from the opposite edge of the video.
    • Clamp to edge: The last usable pixel is repeated.

    TIP You can also automate the Edge Filling mode.

Motion Blur: In addition to stabilizing the video, you can add motion blur to it. Motion blur occurs when a camera was moved quickly like in a fast pan shot. Because this "error" is so familiar, pan shots from modern cameras that don't have motion blur, such as those in mobile phones, look unnatural to us.

Activate Add Motion Blur to create artificial motion blur from the detected camera movement. You can adjust how quickly the motion blur starts on a pan with the Threshold, which specifies how far (i. e. how many pixels) the camera has to be moved from one frame to the next for motion blurring to start.

Event FX or Media FX?

Event

Media

Only the section of the media file referred by the event is analyzed.

The motion analysis is done over the whole media file and can take a long time

Changing the event's start and/or time in the media file makes the analysis invalid and it has to be repeated.

The motion analysis covers the whole file so event editing is possible after applying stabilization.

Point visualization options are available in Expert Mode.

Point visualization in Expert mode is not available

Additional controls of the Expert mode

In Expert mode you get additional controls to fine tune the analysis accuracy with internal parameters of the analysis algorithm. When you switch between the Accurate and Fast methods you see that they are in fact just preset combinations of these parameters and thus many more combinations are possible to find the best working one for your specific footage.

Smoothing Parameters animation: Expert mode provides additional Smoothing control parameters. Animate buttons for each of the different components of detected motion enable you to activate or de-activate each motion component separately over time to even better separate intended from unintended motion.

Visualization: Click Show Points to see points of interest (feature points) and their tracking vectors over the next frames. The track length of the vector indicates the number of frames a feature point could be tracked though the video. To hide points with a shorter track length increase the Minimum track length value, so you see only points with a longer track length that are more likely the correctly tracked ones.

The feature point visualization has some restrictions:

  • It works only when Video Stabilization is applied as an Event FX

  • The point data are not stored in the project file, so feature points are only available after the analysis until the end of the session. If you want to see them later in a saved project, you have to clear and re-analyze the motion data.

  • There's no real-time update of the point visualization during video playback, but you can seek on the timeline to see the points in a different part of the video.