20 Replies Latest reply on Nov 17, 2008 1:08 PM by (Christopher_Prosser)

    aliasing on text

    Dan Jacobsen Level 1
      hi there,

      sometimes when i have a few effects like roughen edges on text i get a terrible aliasing like effect on the vertical edges. really noticeable steps.

      is there anything i can do to get rid of this? or do you know what causes it?

      cheers
        • 1. Re: aliasing on text
          A. Cobb Level 3
          Do you have Pixel Aspect Ratio Correction turned on? It can create horrible horizontal aliasing (which manifests as vertical lines), but these artifacts will only be present in the preview, not the final render. Disabling PARC will make these artifacts go away, but at the cost of the preview pixels being forced from their correct aspect ratio to square, which leads to the preview image being squashed or stretched.
          • 2. Re: aliasing on text
            Dan Jacobsen Level 1
            thankyou. that makes it a lot better.

            it's still there a bit but i think that's just down to resolution.

            cheers
            • 3. Re: aliasing on text
              Dan Jacobsen Level 1
              ok. further to this, i've just had a job sent back because of the jagged edges.

              the text is a bold italic font and it's over a bright pink bgnd (nice!)

              the text slightly moves forward using scale.

              the edges are really breaking up. it looks like aliasing but on the off-vertical edges.

              it's better on black but as soon as you put it on pink it looks dreadful.

              my comp is D1/DV PAL widescreen. it looks bad on the mac monitor and on an lcd tv and a pal broadcast monitor. these 2 are being fed by a black magic card.

              i then render it out as a uncompressed quicktime and import into a smoke. it's then output to digibeta tape.

              at all stages it looks equally crap.

              can anyone help with this? i'm at a lose.

              cheers
              • 4. Re: aliasing on text
                (Steve_Patterson) Level 1
                Having the extreme contrast of black on pink won't help the issue in any video format. Are you actually applying roughen edges? What other effects do you have on the text? If you disable them, does the text look sharp as expected?
                And when you scale, are you scaling live type/vector type as opposed to a raster imported layer?
                • 5. Re: aliasing on text
                  Andrew Yoole MVP & Adobe Community Professional
                  Can you post a still of the problem frame?
                  • 6. Re: aliasing on text
                    Mylenium Most Valuable Participant
                    I'm not sure if this is really an aliasing issue. There are a few questions here:

                    - What kind of pink? If it's a pure red pink, naturally it will span the largest possible range in YUV space, meaning the contrast is probably going out of spec.

                    - What kind of text, how do you transform it what effect order (as laid out by the others)?

                    - Is the bold nature of the font created from a proper font contour, using faux bold or even worse, by applying layer styles/ effects to make it fatter?

                    Any of the above or combinations of them could cause the problems you are seeing. Also check for correct field order on rendering and any potential unmultiplied vs. premultiplied Alpha issues your application of effects may introduce.

                    Mylenium
                    • 7. Re: aliasing on text
                      Dan Jacobsen Level 1
                      thanks for the help guys.

                      I recreated the text in smoke with anti aliasing on and a bit of softness and then imported them into AE as 720x576 white on black stills.

                      I then put all the same effects on them and they looked so much better.

                      could you tell me how to post a picture here? and i'll stick one up.

                      the text is actually white on pink. the pink is RGB = 242,0,126.

                      the effects i'm using are sapphire glow, blur and lens flare. but the edges are just as bad with these turned off.

                      the text did look better on black and worse when the pink was introduced.

                      i was using scale on the text layer. so it wasn't rasterised.

                      the text was a natural bold font, no faux bold etc.

                      i also don't think it's a rendering thing as it looks bad while i'm working on it, looking at it on a PAL monitor.

                      thanks for the help. i'll post a pic when i find out how.

                      cheers
                      • 8. Re: aliasing on text
                        Mylenium Most Valuable Participant
                        Sounds very weird. For pictures to appear, you'll have to host them externally, unfortunately, and post a link. Try photobucket or flickr. we sure would like to find out what's going on here.

                        Mylenium
                        • 9. Re: aliasing on text
                          Level 1
                          >the edges are really breaking up. it looks like aliasing but on the off-vertical edges.

                          >it's better on black but as soon as you put it on pink it looks dreadful.

                          You could be running into quite a number of things. Most likely it's the high contrast edge between the text and background (pink?) with the slow crawl that's making it sizzle (aka mosquito noise). Is it anything like this: http://www.highdefinitionblog.com/?page_id=101

                          A whole image blur may make it passable post quantization and compression.

                          -
                          • 10. Re: aliasing on text
                            Dan Jacobsen Level 1
                            ok. here we are. original is the one AE generated, smoke vers is a rasterised caption white on black generated on smoke then imported.

                            when it moves it looks a lot worse.

                            http://s420.photobucket.com/albums/pp283/HalloweenJack2/?action=view&current=Original.jpg

                            http://s420.photobucket.com/albums/pp283/HalloweenJack2/?action=view&current=SmokeVers.jpg

                            thanks again.
                            • 11. Re: aliasing on text
                              bogiesan-gyyClL Level 3
                              No help at all, sorry.

                              I've never used a smoke thingy but your "original" looks nothing like my standard AE text objects which are always fabulously clean and sharp with absolutely no aliasing or jaggies or stair steps.

                              The other wonks who have joined the discussion are far better at debugging things like this than I but I would be going back to the original text file, effect, or layer and seeing where in the render or nesting pipeline it starts to go jagged on you.

                              Hope you get it fixed. I just don't ever have this issue with AE text layers.

                              bogiesan
                              • 12. Re: aliasing on text
                                Dan Jacobsen Level 1
                                thx anyway.

                                so you can see what i mean?

                                this is PAL so the res is just 720x576.

                                It's on the text right from the start, with all effects off. but, it's much worse on the pink. the other effects don't really change it.

                                wonks is a great word. what does it mean exactly?
                                • 13. Re: aliasing on text
                                  Mylenium Most Valuable Participant
                                  Mmh, the smoke* file looks considerably softer, possibly due to a different sampling pattern. Apart from the usual conditions where this issue would appear and which I already mentioned, I cannot trigger the behavior. My guess is that you encounter an odd combination of your lensflare effect, blendmodes and the text's white pixels not being normalized properly. That's one for Chris to answer, so let's wait what the Mr. Dev has to say about it. ;-)

                                  Mylenium
                                  • 14. Re: aliasing on text
                                    Dan Jacobsen Level 1
                                    yep. the smoke caption is softer. it has anti aliasing controls and a softness parameter for these. perhaps that softness is all that's needed to take the roughness down. tomorrow i'll try turning the AA off on the caption and import it again.

                                    but forget the effects, the caption looked the same without them. it looked better on black and worse on pink.

                                    even with no scale transformation it looked ragged.

                                    if anyone can, try a bold italicised font on that pink. it's RGB is 242,0,126 and it's 8bit PAL 720x576.
                                    • 15. Re: aliasing on text
                                      Andrew Yoole MVP & Adobe Community Professional
                                      Here's my own attempt. No discernible issues with edges here. Have you tried using alternate fonts?

                                      http://www.andrewyoole.com/forum/pink.jpg

                                      Also, are you using an additive blending mode, such as Add. The combined luminance of the edge pixels with the background can have a nasty effect on their look - sometimes.
                                      • 16. Re: aliasing on text
                                        Dan Jacobsen Level 1
                                        thx for trying that Andrew. yes yours looks fine.

                                        here's another. no effects, no grad, different font:

                                        http://s420.photobucket.com/albums/pp283/HalloweenJack2/?action=view&current=test0000000.j pg

                                        it was on add mode, but changing to normal had no effect on the edges.

                                        her's one with bigger text:

                                        http://s420.photobucket.com/albums/pp283/HalloweenJack2/?action=view&current=testbig000000 0_1.jpg

                                        this looks more like yours. so the size isn't helping.

                                        the large one looks fine on my mac's monitor. but on the PAL broadcast it has distortion in the pink around the text. looks like compression artifacts a bit. is it called mosquito noise? when i add glows to this it seems to increase the problem.

                                        more and more it seems like a lot of things going on here. i could put it down to a bad combo of contrast and res...

                                        ... but you guys have seen the original and the small 'jagged one in this post? should my captions look better than that?

                                        cheers
                                        • 17. Re: aliasing on text
                                          Clive555
                                          Dan I am in seriously esteemed company here, so I doubt that I will make a significant contribution. Reading through your post, I have had similar issues at various times in the past. The reason has always been a badly written font. Is the font you are using, from a reputable source, like Adobe, etc?

                                          If you create the text with the same font with no effect on it, what does the output look like?

                                          Maybe also try the same effect, but with a different font. What are those results?
                                          • 18. Re: aliasing on text
                                            bogiesan-gyyClL Level 3
                                            > The reason has always been a badly written font. Is the font you are using, from a reputable source, like Adobe, etc? <

                                            Sean, thanks for the contribution.
                                            A typeface can be interpreted differently by different applications. True.

                                            bogiesan
                                            • 19. Re: aliasing on text
                                              Dan Jacobsen Level 1
                                              Thanks. it was the same with no effects and i tried it with ariel with the same results.

                                              I going to put it down to a combination of factors, mostly the high contrast.

                                              If it happens again i'll soften the edges. it's only really been noticeable twice in the 2 or 3 years of doing jobs on AE so i'm going to call it a day.

                                              thanks for all your help everyone :)
                                              • 20. Re: aliasing on text
                                                Level 1
                                                I agree. I looked at it, and I'm choosing to blame the particular color combination and hard edges on the font with a gentle slope.

                                                --c