Review: proDAD Mercalli V4 Stabilizr Plug-in

Analysis

While Mercalli analyzes the video, you’ll see the Video Preview window shown in Figure 4 (below). At the bottom is a small banded chart. This will likely have several red vertical bars, indicating areas requiring stabilization.

Figure 4. The Video Preview window. Click the image to see it at full size.

Moving the Avoid Border slider option (Figure 5, below) will increase/decrease the space between the bars in the chart. This is a terrific starting (and sometime-finishing) point in the Mercalli V4 stabilizing process.

Figure 5. Move the Avoid Border slider to increase or decrease the space between bars in the chart.

Here, I recommend choosing the Horizontal (Figure 6, below) or Vertical (Figure 7, below) option in the Display Result menu option. This allows for a split-screen display of the video so that the effects of stabilization may be observed while watching the original video.

Figure 6. The horizontal split-screen display. Click the image to see it at full size.

Figure 7. The vertical split-screen display. Click the image to see it at full size.

For some, this may be a preferable method as it provides instant feedback on settings, without the need to pre-render in the background (host application-dependent). You can adjust settings while looping the video, which enables tweaks and fine-tuning of the settings while saving tremendous amounts of time.

If the General Settings don't quite meet the desired or expected result, try changing the camera setting from (for example) Universal Cam to Rock-Steady Cam. This will require another Analysis, but in playing with various settings and footage types, I found this made a tremendous difference. For example, using Rock Steady vs. the expected Sport Cam mode yielded a significantly better result. Just how Mercalli V4 makes these calculations in the background is unknown and not obvious, yet it’s clear the algorithms are well-chosen and well thought-out.

Rolling Shutter Compensation

Sometimes an image includes “Jello” or “wobble” that results not from an unstable camera, but rather the manner in which a CMOS imager deals with video. “Jello-cam” is a nasty artifact of all CMOS cameras that don't offer Global Shutter, and particularly in high shutter speeds found in most outdoor/brightly lit scenarios.

Mercalli V4 has a fix-it option for this sort of video artifact, and it does it pretty well. However, it is painfully slow and processor-intensive on all but the fastest CPUs, so be certain your footage needs it before inserting it into your workflow. Unless you absolutely needed, keep the Rolling Shutter Compensation option unchecked to disable it (Figure 8, below). That said, when it’s required, Mercalli’s Rolling Shutter Compensation does an admirable job.

Figure 8. Rolling Shutter Compensation deselected

In the before and after videos seen below, the Polaroid Cube (notoriously bad for its extreme wide angle and Jello-cam) was used for test footage capture. Mercalli does an amazing job of taking exceptionally bad video and repairing what it can. It is by no means perfect, yet the improvement is remarkable.

Polaroid Cube before:

Polaroid Cube after: