MIMF
Guest
|
 Posted:
Wed Jan 26, 2005 3:59 pm Post subject:
Blurry title |
|
|
Hi
I created a short video with some titles at the beginning (name of the
video, who directed it, cast and so on). I did everything in
uncompressed AVI format and it looks fantastic when played back.
However, when I compress the video to DivX or XVid, the titles at the
beginning looks really bad, blurry and unreadable. The titles are BLUE
(0,0,255) on BLACK background, pretty small (but perfectly readable
when uncompressed). No matter what bitrate nor quality setting I choose
in DivX/XVid dialogs, the letters are all blurry up and look
horrendous. The remainder of the video, which is shot with a camera,
looks good even with low quality DivX settings. I even tried MJPEG,
cinepak, they all make the title look disastrous. Is there a way around
this, or I simply have to change the color and increase the size of the
title?
Thank you.
|
|
Jan Panteltje
Guest
|
| Posted:
Wed Jan 26, 2005 7:54 pm Post subject:
Re: Blurry title |
|
|
On a sunny day (26 Jan 2005 02:59:04 -0800) it happened "MIMF"
<mimf@onvol.net> wrote in
<1106737144.854299.309020@c13g2000cwb.googlegroups.com>:
| Quote: | Hi
I created a short video with some titles at the beginning (name of the
video, who directed it, cast and so on). I did everything in
uncompressed AVI format and it looks fantastic when played back.
However, when I compress the video to DivX or XVid, the titles at the
beginning looks really bad, blurry and unreadable. The titles are BLUE
(0,0,255) on BLACK background, pretty small (but perfectly readable
when uncompressed). No matter what bitrate nor quality setting I choose
in DivX/XVid dialogs, the letters are all blurry up and look
horrendous. The remainder of the video, which is shot with a camera,
looks good even with low quality DivX settings. I even tried MJPEG,
cinepak, they all make the title look disastrous. Is there a way around
this, or I simply have to change the color and increase the size of the
title?
Thank you.
Blue is the lowest 'intensity' color, white is made up of 11% blue, 30% red, |
and 59% green (some other standards exist).
So blue, and without ANY Y value (luminance) is the WORST you can do for
subtitles against a black background.
It is only 11 % signal (relative to 0% black)..
You will have to reduce saturation and add some luminance.
And also when played back via PAL on a TV set, blue will be noisy and even
more bandwidth limited.
Blue is fine against a white background (100% - 11% = 89% contrast).
So, unless you can do it again with say green or yellow, or a Y component,
ANY compression system will have trouble...
Compression 'rounds' the changes between the background and subtitle,
(some bandwidth reduction), so you get a vague 11% 'hop' in the blue signal
only, not very visible.
One should, if at ALL possible, use character outline, a grey outline may help
you here too (say 50 %).
But that is an artistic decision.
You should read up on colormetrics, and then next time you select colors go
for sufficient contrast. |
|
FAQ
Memberlist
Register
Profile
Log in to check your private messages
Log in