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Old April 12th, 2007, 03:35 PM   #1
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reducing jitter on still image pans in AE...

Hi guys, I am desperate for some help on this issue.

I have a panoramic picture that I import into after effects and keyframe so that the view pans from the middle of the picture out to the far left, then the far right then returning to the middle. I overlay video over the top of this and set the parent so that it follows the keyframe. When i export the video and convert to an mpeg using mainconcept mpeg encoder I see serious jitter when the pan is moving, especially at the faster end of the pan (as i have enabled easy in and out on the keyframes). This is especially noticeable when watching on a television, which is what the clip will be intended for...

I am unsure of whether the usual rules of deinterlacing and field dominance etc is applicable seeing as i'm using a still image and not a video.

I have tried the following adjustments but none have led to success:

- imported the photo into photoshop and changed the pixel aspect ratio to the 4:3 standard option

- added motion blur

- selected interpret footage

- enabled frame blending

if anyone can sort this simple but annoying problem I would be VERY greatful...

David

Last edited by David J. Payne; April 13th, 2007 at 08:54 AM.
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Old April 12th, 2007, 08:45 PM   #2
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What kind of jitter?

Are you viewing the video on your computer monitor or a TV? Since you said you are converting it to Mpeg using the mainconcept encoder, I'm going to assume TV.

When you encode the video, make sure you set the correct field (top or bottom). Otherwise when you view it on the TV, the image will look like it jumps ahead one frame, then back.
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Old April 13th, 2007, 05:12 AM   #3
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Quote:
Originally Posted by John Huebbe View Post
Otherwise when you view it on the TV, the image will look like it jumps ahead one frame, then back.

John, thanks for your reply. That is exactly the type of jitter I'm seeing, however I just put the uncompressed avi onto a disc and read it with a divx dvd player and I still see the jitter.

I also tried converting in mainconcept with top fileld first, bottom field first and progressive, none of which sort the issue...

I am well and truly stumped...!
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Old April 14th, 2007, 02:51 AM   #4
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Hi David,
The jitter coud be generated by the movement itself. When you move a still using two (or more, doenst matter) keyframes sometimes could happens that the interpolation gives results that doesnt match an exact pixel number but fractions of pixels.
You can try to modify this code http://aenhancers.com/viewtopic.php?t=457
to work with pan intead of scroll (it should be very simple)

Hope this helps
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Old April 15th, 2007, 02:12 PM   #5
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Martin,

thanks for your reply. Unfortunately Im a relative newbie compared to you guys and I dont have a clue what to do with this code...

David

p.s - I have uploaded the photo I am having trouble with incase anyone else fancies having a play to see if they can create a pan that doesnt jitter on tv playback.

www.rideoutproductions.co.uk/Copy4.jpg

Last edited by David J. Payne; April 16th, 2007 at 08:29 AM.
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Old April 18th, 2007, 10:22 AM   #6
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I have both machines rendering right now (and will take a while) but Ill try to put the image and write the code for you (and explain how to use, of course) so you can reuse in the future.
Give me some time.
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Old April 19th, 2007, 09:33 AM   #7
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Martin,
I'd appreciate that. Many thanks
David
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Old April 25th, 2007, 05:35 AM   #8
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Hi David,
Im back again.
Sorry for the delay but I couldnt finish my rendering (the system said around 450 hours!!!) as soon as the render finish I will make the code.
Sorry again
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Old April 25th, 2007, 07:14 AM   #9
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450 hours?! wow.. thats a pretty heavy project...

Ok no problem, I will keep checking back to see if you've replied. I should be starting the work that needs this info on tuesday the 1st of May, but take your time. Whenever you get a chance I'd appreciate it.

David
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Old May 3rd, 2007, 11:11 AM   #10
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Martin,

Any luck with this? Im starting the work now and would be super chuffed if i could solve this problem.

Thanks
David
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Old May 11th, 2007, 03:41 PM   #11
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Did you say your jitter is a frame forward then one back through the whole pan? I had this problem and it was because I was rendering lower fields first, rendering upper fields first fixed it. -that depends on where it's going, in my case it was avid HD. Play with the fields: lower, upper, and off -then do a test.
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Old May 12th, 2007, 11:11 AM   #12
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Aric,
thanks for the suggestion, that was one of the first things i tried and it did not make a difference. Ive had that problem with video before but when panning accross still images clearly something different is causing the jitter...
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Old May 14th, 2007, 02:10 AM   #13
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Are you changing the field settings in AE or in the mpeg encoder?
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Old May 15th, 2007, 11:57 AM   #14
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Quote:
Originally Posted by Mikko Lopponen View Post
Are you changing the field settings in AE or in the mpeg encoder?
I have tried both. I also played back to avi before conversion with different AE field settings and I get the same result on playback
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Old May 24th, 2007, 04:56 AM   #15
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Hi David,
Im really sorry for the delay (it was absolutely impossible to use my machines).
I made two differet codes and both didnt work ok enough but finally I discovered that using a directional blur with the same direction as the movement the jitter dissapears completely. Also I keyframed the blur to use more blur in the fast moving parts and going to zero when the image stops and stays still.
It seems that the problem is with the sharp edges in the areas where you have high contrast for example the windows (and not the tree that has no jitter). That means that the ultimatte solution would be to make a rough mask aroun that objects and use the directional blur to maintain a clear image and get rid of the jitter (anyway I found that to use the blur in the whole image is quite ok).
I think the problem was caused not by AE but from the ocular retention. I mean, the lack of a real moblur.
I hope is not too late for you.
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