Great Titles article and "Keyline"

[Hulk]

There is a good article on the Cow forum about titling with the DV codec.

I have two questions:

What is a keyline?

How can I control the percentage black in a title in MSP7? I usually do white on black at 170/170/170.

- Mark

[Dr Mordrid]

A "Keyline" is an outline around the overlay. In the case of fonts it's a border not of the fonts field color.

You can do this in MSPro's titler and set its color & width in pixels. This is a very common practice in broadcast titlers and prevents a lot of degradation.

The color used is generally a middle grey, black or be the same hue as the font but with 50% less lumance.

Using too high a white/gray value over a pure black background can cause artifacting (and in NTSC: audible noise!!) because of the high frequency edge, but again a grey border around the font can mitigate this.

You can set the default background color that will be used behind keys in a blank portion of the timeline in File/Preferences.

Dr. Mordrid

[Hulk]

Thanks for the info. I had noticed this type of outline used on TV titles to help the title "stand off" from the image but didn't know it was referred to as a keyline.

Good info here for creating clean, readable titles within the capabilities of the DV codec.

- Mark

[colinbr]

The article recommends

"keep all color channels within the legal limits of 16 to 235 in any R, G or B channel"

presumably for NTSC. Is this the same for PAL?

Why is this important? If the colour is out of NTSC or PAL gamut then will some sort of clipping occur with possible loss of detail in areas of strong saturation?

If so I would not have thought it would make much difference for flat (undetailed) text.

And why is there a lower limit?

[Dr Mordrid]

PAL also has color limits, though they are different from NTSC's because of signal differences.

The bottom line is that there isn't enough bandwidth in a TV signal, NTSC or PAL, to broadcast the full 24 bit palette so comprimises had to be made and we have to reflect those in our edits.

Both NTSC and PAL use a reduced color palette that manifests in being limited to certain levels. In NTSC the limits are 16-235 as you noted. In PAL the limit is 0-235. The lower limit is the definition of the black level.

Dr. Mordrid

[Jerry Jones]

Here's the article, in case anybody is curious.

http://www.creativecow.net/articles/hodgetts_philip/titles/index.html

Jerry Jones

http://www.jonesgroup.net

[Hulk]

Very informative article. Not wordy, but a great outline of important information.

I've also noticed that a lot of "pro" TV spots use a slight drop shadow to set off titles. It's often so minimal that you almost can't notice it, but if it weren't there you would notice the difference in how much harder it would be to read the text.

- Mark

[Dr Mordrid]

This is to handle NTSC's need for a "ramp". NTSC requires a ramp (a few pixels worth of border or anti-aliasing around a high frequency edge) to prevent artifacting.

Dr. Mordrid