11 Replies Latest reply on Mar 10, 2014 10:06 AM by Marc Lucas

    Jagged text at 32bit

    Marc Lucas Level 1

      Had a colour effect that was being used and it was only achieved by using a 32bit colour space. However the text came out jagged in the render. I changed the text to 16bit and all was fine. So question is why would the text be jagged in 32bit is there a specific reason for that?

       

      Thanks

        • 1. Re: Jagged text at 32bit
          Szalam Adobe Community Professional & MVP

          It would be handy to know what effects you were using. Screenshots of your composition window with the jagged and smooth text would also be helpful. Also, what version of AE are you using?

          • 2. Re: Jagged text at 32bit
            Marc Lucas Level 1

            Hi

             

            I am using the Glow effect on the text. I have been looking at this an found it is something to do with the Glow effect. I need to be working in 32bit to gain the Glow effect that I have. I am rendering out a ProRes 4444 RGB with Alpha bcause the text is being overlayed in FCP. When I import the clip into FCP I set the Alpha Channel to 'Black' that gets rid of any black outlines around the text.

            The screen shot attached shows the text with & without the glow effect applied. Not sure whether you can see in the screen shot but the text without the glow effect is perfectly OK which brought me to the conclusion that the glow effect for some reason is doing something to the text on export?

             

            AE 12.2.1.5

            Screen shot 2014-03-07 at 16.53.02.jpgScreen Shot 2014-03-07 at 16.58.59.png

            • 3. Re: Jagged text at 32bit
              Marc Lucas Level 1

              Possibly not relevant but here is a screen shot of the Canvas the text looks fine

               

              Screen Shot 2014-03-07 at 17.01.10.png

              • 4. Re: Jagged text at 32bit
                Dave LaRonde Level 6

                I am rendering out a ProRes 4444 RGB with Alpha bcause the text is being overlayed in FCP. When I import the clip into FCP I set the Alpha Channel to 'Black' that gets rid of any black outlines around the text.

                 

                Try rendering the alpha channel movie with a STRAIGHT -- i.e., not Premultipled -- alpha channel.

                • 5. Re: Jagged text at 32bit
                  Szalam Adobe Community Professional & MVP

                  Marc Lucas wrote:

                   

                  When I import the clip into FCP I set the Alpha Channel to 'Black' that gets rid of any black outlines around the text.

                  I'm not familiar with how FCP works, but are you rendering an alpha channel out of After Effects and using the rendered alpha channel in FCP or is FCP faking the alpha channel based off of what is black in your image? What happens if you act as if there's no alpha channel and just set it to screen over your footage in FCP?

                   

                  How does the render look if you import it back into AE? If it looks fine in AE, then something in how FCP interprets the file is messed up.

                  • 6. Re: Jagged text at 32bit
                    Rick Gerard Adobe Community Professional & MVP

                    You should always use Straight alpha channels for any NLE I have ever used. I've never rendered a pre-multiplied alpha with a black background and only once or twice have I needed to render pre-multiplied with a colored background to kill some fringing. I don't know why pre-multiplied is the default. I've changed it to straight in all my Output Module presets.

                     

                    I am not sure what I'm looking at in your screenshots. Both look identical except for scale. Here's one overlaid on the other.

                     

                    comparison.jpg

                    The larger image looks like the view is scaled above 100%, the bottom image looks scaled down. I don't see obvious pixelization in either. The only way to judge an image is to look at it at 100% scale so you are looking at at every pixel. 200% or higher is useful to pick out small details, but you can only judge the effectiveness of antialiasing at 100% zoom factor and 100% sca.e.

                     

                    Here are other questions about your sample images: Is one of them from Final Cut? What does the image look like in ProRez 444 in AE? In FCP? If you are judging the render with the Quick Time Player  the QT player does awful things with alpha channels because the QT player does not support them.

                     

                    Have you tried rendering to a Tiff sequence? You can get higher bit depth there and FCP will handle the sequence just fine. Have you tried Jpeg 2000 (supports straight alpha) or QT png (also supports alpha) or any of the other codecs that FCP supports like Black Magic 10 bit or Avid's 10bit?

                    • 7. Re: Jagged text at 32bit
                      Marc Lucas Level 1

                      Just checking back in.

                       

                      I have rendered out with Straight Alpha and still the same problem, likewise with the Tiff sequence.

                       

                      I really think its something to do with the way the Glow effect works with the 32bit mode or just the Glow effect in general. Reason is I have enclosed some test files of two lines of text one with the Glow effect applied the other without. When the Glow efect isn't applied the text is perfectly fine. The text scale is 100%

                      I have enclosed a screen grab of the Glow effect parameters.

                      I have also imported the effect back into AE and still the same problem.

                       

                      https://www.dropbox.com/s/zi1bd87engzlwhn/Test%20Renders.zip

                      • 8. Re: Jagged text at 32bit
                        Rick Gerard Adobe Community Professional & MVP

                        Here's a close up of your text at 400%

                        Screen Shot 2014-03-10 at 7.32.49 AM.png

                         

                        I see no difference in aliasing on the curves. Your render looks just as I would expect it to look and there is no banding on the glow. I'm not sure what you are expecting from the vdieo of how you are judging the quality but it looks just fine to me.

                        • 9. Re: Jagged text at 32bit
                          Marc Lucas Level 1

                          Thanks for your reply Rick.

                           

                          Do you see any alising on these two then? One a screen grab from AE (which looks fine) and the resulting render out of AE where I can see alising on the curves of the S but am I being to anal about the quality. The scale is 100% still but I've incresed the size of the charactures.

                           

                          https://www.dropbox.com/s/j3rdecp03iqog4n/TEXT.zip

                          • 10. Re: Jagged text at 32bit
                            Rick Gerard Adobe Community Professional & MVP

                            You are being anal about the quality. I suspect a background in print. The only way to judge video is in playback at full frame rate. Any other judgement call is meaningless. I see no difference and nothing that isn't the usual way that After Effects renders text.

                             

                            You are playing with potential problems with 100% white text against black backgrounds because the antialiased edges are going to beg the compressor to block up the subtle colors, but OTT everything looks completely normal.

                            • 11. Re: Jagged text at 32bit
                              Marc Lucas Level 1

                              No not a BG in print.

                               

                              The text, with blue effect, is actually going over live footage for a TV commercial so needs to be right, hence the posts on here.

                               

                              Thanks for your words of wisdom on this.