3 Replies Latest reply on Jun 14, 2012 7:41 AM by Vielo

    After render color problem

    Vielo

      http://www.youtube.com/watch?v=ozpFgXeWRGM one of my recent experiments messed up my rendering a bit and every render after this one has the same problem. if you look in the lends flares and gradients the colors a split up into something like layers like some old 90's videogame. i dont know the technichal definition of this but tips on how to fix this because it looks terrible -_- and i rendered that video abt 5 times and eventually gave up and rendered in lossless and came out with 1.5 gigs and uploaded it anyways. hoping that it was just some constraint or filetype that was mussing up my experiments. i was sorely mistaken -_- but back to the point, if anyone has any tips on how to fix that darn color distortion please help!

       

      [edit]

      after looking around some more i figured out the techinchal definiton was color transitions. mine look alot like something thats 16 bit.

      my problem is its not my moniter therfore how do i smooth out my color transitions in my projects to achieve a nice smooth color transitions instead of the blocky 16 bit thing o.o

        • 1. Re: After render color problem
          Mylenium Most Valuable Participant

          It's called banding and there is no way to avoid it 100% with any 8bit format such as H.264 on YouTube. Even if you work in 32bpc in AE, eventually the issue wil lcome back when doing the final compression. It's inherent in the underlying computationa math. The only way to minimize it is to disguise it by adding subtle noise. also reconsider your design - large uniformely colored areas are problematic for any compression and will only intensify the perception of artifacts.

           

          Mylenium

          • 2. Re: After render color problem
            Rick Gerard Adobe Community Professional & MVP

            Screen Shot 2012-06-08 at 10.19.41 AM.png

            These color artifacts started as 8 bit problems that were intensified by compression. Higher data rates help but, as Mylenium said, there's not much you can do about it except add some noise when you're using an 8 bit codec.

             

            Here's the math simplified. Let's look at just the blue channel. You have blue values from 0 to 255 available. let's say your color transition is from a blue value of 50 to a blue value of 60 from left to right. The change is subtle and if the distance between the blue value of 50 and the blue value of 60 is 10 pixels then you'll have a smooth transition. However, if the distance between a blue value of 50 and a blue value of 60 is 200 pixels then you'll have 20 pixels that are 50, then 20 pixels that are 51, then 20 pixels that are 52 and so on. This results in visible banding between the values. Throw in a compression scheme like H.264 and the codec's going to try and group pixels together in as few a color blocks as possible. The lower the data rate, the larger the color blocks. At a very low rate you may end up with just 4 blocks of pixels to cover the value range between 50 and 60 instead of 10. Raise the data rate and throw in multi pass compression and you may end up with 8 blocks of values. Use a lossless compression scheme and you'll end up with all 10.

             

            BTW, AE doesn't do multi pass compression directly unless you load your AE project into the Adobe Media Encoder and do your compression there. After Effects is a Production Pipeline Tool and not a Content Delivery Tool. There is a major difference between the tool. Production Pipeline Tools are specifically designed to maintain quality and retain precise pixel values throughout the production process. Delivery tools are designed to compress in the most efficient way for distribution of content at the lowest possible data rate.

             

            This explanation is very simplified but the information should help you make better rendering and compression decisions.

            • 3. Re: After render color problem
              Vielo Level 1

              i added some textures into some of my new official projects and tried to have no flat color. and it solved the problem entirely thanks for the help!