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  • Chroma keyers

    Hi All,

    I just re-installed my green screen and did some test shots with it.
    It was good, but I do not have any other available to EDIUS plug-ins for chroma keying, and was wandering how good are they?
    Is one really better than the other, or is it just a case of one knowing the software to be able to get the right results from it.

    I thought, that if I post a good green screen file so others could give it their best shot, it would be a good exercise and interesting discussion.

    For those that are interested, I propose to take a still shot just out your window and chroma key it as a background with my footage.
    I would love to see results from as many locations as possible. Also, tell us what plug-in you were using and if there was anything special you had to do.
    I am sure everyone will find it interesting.

    Here are single frames from each take: Tiff1 and Tiff2 (each frame is 19MB, tiff, 16bits) if you want to work with stills.
    Or here is 20 seconds of Canopus HQX encoded mov (183MB, 422) ready for you to just add the water…, I mean background ;)
    And here is my attempt at it, with background from Vancouver, BC rwt1 (37MB, mp4) using stock EDIUS chroma keyer.

    You can use the tiffs to create a picture to share it back with us or use the video if you have a way to post it back for everyone to see.

    BTW: I am not concerned about matching the colors (so it looks like it belongs there, that’s color matching), I am looking for edges, transparences, spills, etc.
    For instance, in my test: I am having difficulty removing the green tinge from tips of her heir.

    I hope to see few different plugins here.
    Thanks
    Rob

  • #2
    I can give you some general rules.

    Good green screen keys are about lighting and presenter position relative to the screen.

    The presenter should be at least 2 feet or just under a metre away from the green screen to avoid green "splash back" from the screen or to avoid shadows, and preferably with a fill light on a dimmer from above the screen to light the back of her head. (it gives a warm glow 3D effect in a 2D plane).

    Think about it this way. Use one set of lights to evenly light the screen and another set of lights to light the presenter as if the green screen wasn't there.

    Edges are generally governed by the quality of the video camera 4:2:0 will not give as cleaner edge as a camcorder that records in 4:2:2 as the colour resolution is much better in 4:2:2.

    Fuzzy or "wild hair" can be more of a problem especially with the presenter too close to the green screen and Robus Key is better than the Edius one at softening the edges, which can help in difficult situations.

    Mike
    Sys4: Z10PE-D16WS MB 2xE5-2696 Xeon 72 active logical cores. EWG9. 64G RAM. Aorus GTX1080Ti. 55" Q7 1500 NIT HDR 4K TV/Storm 3G Elite/Decklink 4K 12G/8CH audio monitoring, Yamaha RXA-870 A/V. Sys1-3 EWG8 + RX-E1+HDBX1000 MIP in HP xw8600 2 x X5492 CPU 8 cores, 8Gig RAM, Quadro FX3800. All sys Fibre to central media pool - 5TB Axus Yotta RAID + QLogic Fibre Switch. Central VCR rack plus YUV & audio to viewing room with Yamaha AX1 7.1 100 watt per channel amp with 1000W sub 63" HD 3D Samsung TV

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    • #3
      Ok if I take your two tiffs I can do better with the Edius key than you have, and of course the hair is worst case as the ends will be hidden by the body in practice.

      Edius key settings

      Cancel colour
      Range 27
      Power 50

      Y=127
      U=102
      V=83

      Chroma
      Base=189
      Range 25

      Luma

      Base 76
      Range 64

      Soft Edge checked

      Auto tracking enable
      skip Line checked
      skip frame not checked.

      The green screen is not evenly lit in the small head shot and to do best for the hair the key fails on the background, so in the Edius keyer a compromise would have to be reached between hair and background key although you can always add a mask in the Edius keyer.

      Interesting that the PNG create still with the Edius keyer creates a black background and using the Robus key it creates a white one however if I create a background clip it saves a still correctly.


      The Edius key is I would describe as more large chunky areas and Robus key is better at fine detail.

      There are 4 png files attached

      0000 and 0004 are using the Edius Key

      0001 and 0002 are using Robus Key

      Robus key will play in Real Time in system 4 in my signature which it didn't before I got the GTX980Ti GPU.
      Attached Files
      Last edited by createmedia; 07-07-2015, 01:24 AM.
      Sys4: Z10PE-D16WS MB 2xE5-2696 Xeon 72 active logical cores. EWG9. 64G RAM. Aorus GTX1080Ti. 55" Q7 1500 NIT HDR 4K TV/Storm 3G Elite/Decklink 4K 12G/8CH audio monitoring, Yamaha RXA-870 A/V. Sys1-3 EWG8 + RX-E1+HDBX1000 MIP in HP xw8600 2 x X5492 CPU 8 cores, 8Gig RAM, Quadro FX3800. All sys Fibre to central media pool - 5TB Axus Yotta RAID + QLogic Fibre Switch. Central VCR rack plus YUV & audio to viewing room with Yamaha AX1 7.1 100 watt per channel amp with 1000W sub 63" HD 3D Samsung TV

      Comment


      • #4
        Originally posted by createmedia View Post
        I can give you some general rules.

        Good green screen keys are about lighting and presenter position relative to the screen.

        The presenter should be at least 2 feet or just under a metre away from the green screen to avoid green "splash back" from the screen or to avoid shadows, and preferably with a fill light on a dimmer from above the screen to light the back of her head. (it gives a warm glow 3D effect in a 2D plane).

        Think about it this way. Use one set of lights to evenly light the screen and another set of lights to light the presenter as if the green screen wasn't there.

        Edges are generally governed by the quality of the video camera 4:2:0 will not give as cleaner edge as a camcorder that records in 4:2:2 as the colour resolution is much better in 4:2:2.

        Fuzzy or "wild hair" can be more of a problem especially with the presenter too close to the green screen and Robus Key is better than the Edius one at softening the edges, which can help in difficult situations.

        Mike
        Hi Mike,
        Lighting in general is as you described: front for the talent, middle for the screen and backlight for the highlights (since '85 I have done few chroma key setups ;) ).

        As for the tiffs, the files are 4:4:4 color sampling with 16bits for each color channel (that's why the files are 19MB each).
        Can't say the same for the mov, HQX will only save 4:2:2.

        That is why you maybe getting better keys from the stills. In my test I used HQX and that maybe weakness of my test output (wanted to use the same files I made available to others).
        Regarding your comment about "...uneven lighting...", I am not at all concerned for two reasons:
        1. The shot is a wide shot and it captures the edge of the green screen that would never be intended to be used. It would always be masked off as you suggested.
        2. It is "chroma key", as long as the background color stays the same (chroma vector), luma should be able to very to some degree without effecting the key.

        Click to Enlarge
        Vectorscope view of the tiff with the green screen in the circle.

        Yes, I heard about Robuskey and would love to see the key in action but with a background, because black or white does not show me any details.
        Also I would never key to a solid color, I would just shoot it on that background for number of reasons.
        But to be fair, I definitely see more details in your Robuskey examples.

        Thank you for taking the time.
        Last edited by GrassValley_SL; 07-07-2015, 12:04 PM.
        Rob

        Comment


        • #5
          I have taken your movie and put a pic in the background.

          The bottom of the hair was very difficult that is about the best I can get it using Robus key.

          It is here

          https://youtu.be/EIwI4yfkD3E

          Mike
          Sys4: Z10PE-D16WS MB 2xE5-2696 Xeon 72 active logical cores. EWG9. 64G RAM. Aorus GTX1080Ti. 55" Q7 1500 NIT HDR 4K TV/Storm 3G Elite/Decklink 4K 12G/8CH audio monitoring, Yamaha RXA-870 A/V. Sys1-3 EWG8 + RX-E1+HDBX1000 MIP in HP xw8600 2 x X5492 CPU 8 cores, 8Gig RAM, Quadro FX3800. All sys Fibre to central media pool - 5TB Axus Yotta RAID + QLogic Fibre Switch. Central VCR rack plus YUV & audio to viewing room with Yamaha AX1 7.1 100 watt per channel amp with 1000W sub 63" HD 3D Samsung TV

          Comment


          • #6
            Originally posted by createmedia View Post
            I have taken your movie and put a pic in the background.

            The bottom of the hair was very difficult that is about the best I can get it using Robus key.

            It is here

            https://youtu.be/EIwI4yfkD3E

            Mike
            Hi Mike,
            If I draw a clock face centered on her nose, from 7 to 5 o'clock I have no problems (although, it is considerably less detail then your stills).
            The rest (bottom) I think could use more gradient in the alpha.
            In preparation of my test output, I did noticed that it was much more difficult to work with dark background than light background and this just proves to me that it was not just me.

            Thank you
            Rob

            Comment


            • #7
              Robuskey has a 30 day trial period. Just go here and download it:
              http://www.isp.co.jp/en/products/robuskey/index.html

              This way you can see what it does first hand.
              Jerry
              Six Gill DV
              www.sgdvtutorials.com
              If you own the Tutorials and you need help, PM me.

              Vistitle YouTube Channel
              https://www.youtube.com/channel/UCMVlxC8Am4qFbkXJRoPAnMQ/videos

              Windows 10 Pro up to v.1803 Tweaks for Edius Users
              http://sgdvtutorials.com/WIN%2010%20...%20V.2.0.0.pdf


              Main System:: Azrock Z97 Extreme 6, [email protected], 32gb ram, NZXT Z63, Win10 Pro 64, Samsung 850 pro, E7.5/8.5/E9 on separate SSD drives, 2TB Sabrent M.2 NVME, BM MINI MONITOR 4K, 12tb RAID 0 on backplane ,2 BD, Dual LG 27GK65S-B 144Hz monitors, GTX 1080ti SC Black.
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