Using mercalli removes imagery

[Davidk]

In another thread, stabilising the (jittery) motion of a clip I used to demonstrate a (separate) issue using mercalli was suggested.

I've viewed the mercalli tutorial from the corel site, which was of an image recorded on a river, and obviously there was image motion arising from the river swells itself in the source file. It certainly looked like it could provide stabilization for the clip I recorded. If not completely, then it would make the clip bounce or jitter (which was caused by me recording on zoom whilst walking) much less apparent.

Running X8 Ultimate. Loaded the clip by itself, applying the filter and analysing the clip to determine the scale of bounce and thus assess an 'average' around which the image frames would be reset was both straight forward and understood. But what it did do after analysis was delete about half the clip image and display the remainder in a 'half-screen' format (black blank screen on LH side, restricted imagery on the RH side). Which was admittedly, considerably more stable than it had been, but the 'price' was unacceptable. Nothing in the filter control panel seemed to change that, and I poked around in it, trying different things and assessing the result, before abandoning the effort.

So, does any expert on mercalli out there
a. know of the any limitations on the filter itself and what it can do? The result I got may indicate a degree of bounce in the source file which is beyond the ability of the mercalli filter to fix.
b. have any suggestions that would allow me to stabilise the imagery without losing most of it?

Davidk

[aljimenez]

Never had your result, and I use Mercalli a lot on almost all my clips. I usually leave all the settings at default in my use. Did you try just dragging Mercalli to your video clip, then selecting Cusomize and simply running it with default settings?
What is the format of your video clip that gave you problems? If you make a small portion of your video clip available I would be happy to try it and see what I get... Al

[Davidk]

Hi Al,

Actually, you were the one who suggested I use mercalli. Recall the video I did of Iguazu falls? here https://youtu.be/x4e1qzR_2Xs
The clip I used for the mercalli experiment is part of that video, "mov04A landing pad 1.mod" which I've stored on MS onedrive here
https://onedrive.live.com/?id=F258AB298 ... A1&group=0
so you can get and play with it.

I suspect that the jitter which caught your attention in the youtube video was the way the recorded image moved around relative to a running title, which probably made the image movement more noticeable.

I tried the default settings and some of the others, but which ones elude the memory right now.

Davidk

[RobertOZ]

Hi Davidk,

Downloaded your clip, applied Mercalli filter, allowed the video analysis to be completed, did not change any of the default settings, Mercalli did an excellent job of removing the shake and plays perfectly, did not notice any degradation of the finished video

[asik1]

Hi Davidk,

Downloaded your clip, applied Mercalli filter, allowed the video analysis to be completed, did not change any of the default settings, Mercalli did an excellent job of removing the shake and plays perfectly, did not notice any degradation of the finished video

Realy Robert? no degradation? I reckon at least 20% zoom was needed by the defaults and on SD that's degradation.

Right is with Marcalli zoom, left without

I cropped a clip one overlay the other

[BrianCee]

actually the right side looks sharper on my screen

[aljimenez]

With SD clip and that much shaking, some degradation will occur, but I think the end result is more watchable than the original.

[Ken Berry]

I've also just put that clip through Mercalli using its defaults and got a much more stable end result than the original. Yes, there is zooming, and for me some minor fuzziness as asik suggested. But as Al says, it is far easier to watch than the original.

[RobertOZ]

Realy Robert? no degradation? I reckon at least 20% zoom was needed by the defaults and on SD that's degradation.

That depends on your interpretation of the word "Degradation" I used the term in the context "A decline to a lower condition or level" the condition has been significantly improved by the use of the filter, of course there will be some zooming, that's the nature of the beast, but the overall result has improved the watch-ability of the clip

[asik1]

Good we agree to disagree.
Maybe it's an issue for a different thread but, my philosophy of video editing is that the video should look as homogenize as possible. Any apparent difference in "pixelation" should be avoided. if a shot texture looks different than it's neighbors the viewer attention draws to that difference more than the shot content.

A possible solution for this ~13sec shot is to use 2-3 stiles and crosfade them.

[Davidk]

Thanks to all for the suggestions.

I tried Roberts' default settings approach and got a completely different result. So clearly I've done something wrong the 1st try. And the result did not seem to be much different from the un-filtered clip on this attempt. The grassy scenes before the zoom out at the close of the clip still bounced around.
For my next try I included some running text, carefully aligned to run across the bottom of the safety screen lines when inserting text: so the text would be in a constant position on the screen. The ideas being that a more stable image would be indicated by the text not bouncing around as much. And this time I screenshotted the UI with clip, a running title and mercalli default window and settings, as here:

and then I ran the filter, as is. It re-scanned: click OK in the filter panel, it runs and then closes the window. But running the "project" with the clip filtered like this still showed the bouncing image and text at the back end. It really did not seem to be much different from the raw clip.

For those who say the image is stabilised with mercalli, what settings did you use?

Davidk

[Ken Berry]

As I said above, I used the default settings and they are identical % figures to those in your image above. Do you not see any zooming at all (apart from your own, of course)?

[lata]

Hi David
Is not the grass being bounced by the down draft created by the rotors, or are you referring to the actual ground surface.

Like others I have applied Mercalli with the default settings and it does remove a lot of shakes, certainly looks better than the original

[Davidk]

Ken Trevor and others all said the filtered version "looked better". Dense yours truly is probably off the page about what looks better, but in the latest experiment I did have the same clip repeated in the timeline - once filtered, and then just plain. And my remark about not much difference was based on the apparent differences between the two when the whole <30 sec project (2 clips in sequence) was played.

In the original clip, the main 'bounce' occurs towards the end of the clip when the helo is settling on the pad, surrounded by a grassy verge which is bouncy over a few seconds, crewman on the pad approaches the helo, and then the zoom out. In the filtered version I get much the same grassy bounce, and thus my remark.

The 2min46sec mercalli tutorial (which I've captured, saved and reviewed several times) displayed a river scene taken from a boat, where the buildings on the far bank of the river are moving in response to wave action causing the boat camera to move up and down (bounce). And let me note here that whilst the degree of movement (bounce) was noticeable, it wasn't large. The filter just removed that perceived up and down motion in the filtered images. So, based on the tutorial, what I expected to see in my clip when the filter was applied was that grassy bounce (which arose from me moving whilst recording on zoom) was noticeably reduced or even eliminated without otherwise reducing the content of the overall imagery. So far at least, that isn't what I see.

Am I being too critical? Is the degree of bounce simply too much for the filter to handle? Can the experts express 'looks better' in terms I can see in this clip?

Davidk

[Ken Berry]

I just rendered it using default Mercalli settings -- Same As Project Settings since I had that box ticked. And rendering took only a couple of seconds -- I would have expected a bit more to take account of the Mercalli filtering.

For me, just about all the handshake of the original is gone -- not all of it but probably 90%, particularly the part where the helo swings around with the tail going to the right of screen. I can see what you mean about the 'bouncy' bit, but while again not all of that is gone, most of it is wiped out by the zoom cutting out a lot of the grass along the bottom right of screen.

Again, I can only say I find it much more watchable. You can still tell it was filmed by a handheld camera. But now it looks like you had much less shaky hands when walking with the camera!