VideoHelp Forum


Try DVDFab Video Downloader and rip Netflix video! Or Try DVDFab and copy Blu-rays! or rip iTunes movies!
+ Reply to Thread
Results 1 to 6 of 6
Thread
  1. Member Rande's Avatar
    Join Date
    Oct 2016
    Location
    United States
    Search Comp PM
    HI,

    I am using a Canon Vixia HF R300 and Pinnacle Studio 17. When I use the Chroma Key on a clip I shot, it leaves a black "noise" residual.

    When I use a demo clip, I can remove the green screen completely.

    Here is an example of my issue, I used a basic orange jpeg for the background after I chroma-keyed on my shot. As you can see, even without me and my shadow, there's a continuous black motion haze/noise.


    https://youtu.be/kL2IaQ6BeJ0

    Is it a setting on my camera for light? I have tried with several different lighting fixtures and without any and still have the issue.

    Thanks for all your help.

    Rande
    Quote Quote  
  2. Member DB83's Avatar
    Join Date
    Jul 2007
    Location
    United Kingdom
    Search Comp PM
    I'll go out on a limb here but why do they call in 'Green Screen' ? Answer. Because the screen is green.

    If you look at photo shoots, what color is the backdrop ? Why it's green. Even if it is not gonna be keyed away.

    There is a reason for this. But do not ask me for technicalities. But I do know that red has compression issues. And orange is nearer red than green.

    Have you actually tried using green ?
    Quote Quote  
  3. I think the OP means that he used a green screen and then used a solid orange background as the replacement for the green screen. Obviously it isn't what he'd probably do in the final shot, but he was trying to troubleshoot the compositing.

    Having said that, I'm not 100% sure I know which problem(s) he is trying to solve. The orange background that replaces the green screen is indeed full of noise. If that is what he is trying to fix, then I'd have to know a lot more about how Studio 17 does their screening. I've done a little of this work, and have helped other people do it, and usually the only problems are those that happen between the foreground object and the green screen, know as "pulling a good screen." Usually you see halos around the person in the foreground, or you see part of the replacement background bleeding through the talent (which is why green or blue is the usual color used, because those colors are not part of normal skin colors).

    So, if the problem he wants solved is the considerable noise left on the orange background, my guess is that is has almost nothing to do with the green screen itself and instead is due to (possibly) really low encoding bitrates coupled with low resolution.
    Quote Quote  
  4. Member Rande's Avatar
    Join Date
    Oct 2016
    Location
    United States
    Search Comp PM
    HI,
    I think I mis-stated my issue. I use a green polyester screen for the background (actually came with a previous version of Studio). After I used the automatic keyer and it completely removed the green background, I saved it and then added the orange jpeg in Studio timeline underneath the clip.

    Does that make sense Mr. Bean?
    Image Attached Thumbnails Click image for larger version

Name:	green screen set up.jpg
Views:	185
Size:	245.5 KB
ID:	38951  

    Quote Quote  
  5. Member Rande's Avatar
    Join Date
    Oct 2016
    Location
    United States
    Search Comp PM
    https://youtu.be/v0lvf_juSW8

    This is the test video I did with a sample from the internet. I used the default green key in Studio 17
    Quote Quote  
  6. You didn't upload what the "before" looked like but very likely the other clip was better lit , or maybe synthetic 1 shade of green (it's an animation so I'm guessing it's likely) . Your clip probably has uneven green screen, suboptimal lighting setup

    When you have noise like that on a single color composite, usually it means a bad key - there are leftover semi transparent pixels in the alpha channel because the "green" actually consists of many different shades of green. ie .it's uneven green screen . If you were to look at the alpha channel in your software after keying, it's probably very noisy.

    An "automatic" keyer probably can't handle your video. You either have to improve the setup or use better software or technique. Or if it has more manual controls try fiddling with those. For example, you can improve on it by using a "garbage matte" or mask, to isolate only the closer pixels, discarding the far pixels (they don't even get exposed to the keyer)

    Compression mentioned earlier is also an issue (for example YT re-compresses everything) and partially makes the problem worse, but that's not likely the underlying issue. It only exacerbates the real issue
    Quote Quote  



Similar Threads