Title Edges

[Tom Wolsky]

What format are you working in? DV? That’s about it. Trying putting an edge on the text so it’s consistent. Pale blue on white some very illegible. We need contrast for legibility.

All the best,

Tom

Class on Demand DVDs “Complete Training for FCP6,” “Basic Training for FCS2” and “Final Cut Express Made Easy”
Author: “Final Cut Pro 5 Editing Essentials” and “Final Cut Express 3.5 HD Editing Workshop”

[Ian Bennett]

I’ve tried it in Uncompressed 8bit and Apple Prores, same result. Even with an outline.

Another weird thing is that when I make the background color black instead of white, then that same edge is lighter than the text color.

[David Frisk]

This is because of the color sampling that’s going on (all the 4:1:1 and 4:2:2 color space and stuff you hear about). Each group of pixels next to each other get averaged together for their color information. If you have a solid color within the text, then those colors will remain the same because they’re just averaging the pixels with other pixels of the same color. Near the edges of the text, however, the edges are getting sampled with those in the background and coming up with new colors.

The colors get averaged horizontally (in most cases), which is why you would see the effect in the vertical parts of the letters, and not the horizontal lines. I believe whether you use uncompressed material or not doesn’t matter, because at best it’s being output to a monitor with 4:2:2 color sampling if you have an SDI out. You’d need some type of 4:4:4 output in order to not have the problem.

Hope that helps explain your problem. I was dealing with the same issue just last week.

[Ian Bennett]

Thanks for the detailed response!

I doubt I’ll be able to export it out 4:4:4 anytime soon, hah. Is there anything you could suggest if the ultimate destination is NTSC out using component? Did you work around it?

[Larry Asbell]

Do you have a chance to view the NTSC signal right out of your
card onto a better NTSC monitor? If you could you will probably see that the problem is not there.

David may be right, but it’s possible that your problem is something different.

In analog video it’s called ringing or overshoot. You see it when the signal tracing a given scan line transitions rapidly from a high(video level) to low or low to high, which each scan line does as it makes a vertical edge. Lower quality or older processing circuits in vtrs, monitors, encoders, switchers, DA’s etc. add overshoot to your signal which shows up as you describe. For example a white letter against a dark background will have a brighter left edge where each scanline has overshot the brightness it was supposed to rise to. Sometimes just to the right of that is a darker “trough” where the level goes bit low before it settles down to where it’s supposed to be for the white letter.

I don’t know the quality or condition of your gear but I’m sure that if you make a VHS dub of your program and play it back you will see what I’m describing. If your monitor or something in your NTSC signal path is in poor shape you may see this without the VHS dub.

– Larry Asbell

[David Frisk]

To fix it, we had to mess with the background. I don’t think it has to do with the luma so much as the chroma, because with the color sampling, the luma levels are retained while the chroma values get shifted. We had such contrasting colors between the letters and the background that it was creating a lot of problems. Then again, it also helped when we either lightened or darkened the background. I think that might have had to do because the lightness levels were so close, but the colors were opposite, and so shifting the luma further….wait….now I’m just confusing myself! It’s enough to drive a person nuts!

Well before I confuse myself any further, and possibly give you bad information as to what’s happening and why it is (which could very well be the case), I just know that some slight color shifting seemed to have solved my problem. It also didn’t help that my letters were fairly small and so the edges seemed to be so much more problematic than if the text were larger.

Sorry I couldn’t be more helpful.