Re: NTSC video and color management?
Re: NTSC video and color management?
- Subject: Re: NTSC video and color management?
- From: Simon Minshall <email@hidden>
- Date: Mon, 14 Feb 2005 09:44:57 -0700
Ray,
Are you aware that in NTSC (and PAL) that according to CCIR601, 8bit
values above 235 and below 16 are not used. Strictly speaking they are
allowed in the standard and are sometimes used in post production, but
when broadcast these values 1-16 and 235-255 will be legalised by
clipping or compression and you won't see them. The code value 0 is
reserved.
If your trying to profile the system, be aware that video capture,
output and some display devices can clip, clamp or compress your values
and give you unpredictable results.
If you don't have a copy of Charles Poynton's Digital Video and HDTV,
you should get one.
Simon
On Feb 13, 2005, at 13:12, Ray Maxwell wrote:
Hi Group,
I am concerned with creating graphics on PC's and Mac's and then
moving it into video production applications.
When I create a graphic in the NTSC color space in Photoshop it allows
me to create colors where RGB values go from 0 to 255. If I then run
the "NTSC Colors" filter, the saturated colors, Red, Green, Blue,
Cyan, Magenta, and Yellow are limited to values less than 255. Some
are cut back as far as 170. Note that the color white is still 255,
255, 255.
Is this limiting due to NTSC composite encoding?
If all of the video production were kept as component video (Y Cr Cb)
could I use the full 0 to 255 that can be reached in the NTSC 1953
profile?
I am trying to understand where the bottle neck is in the video
production process. Is it the NTSC 1953 profiles or is it further
restricted by the NTSC composite encoding?
Can anyone point me to a book on this subject?
Bruce are you going to write a book on "Real World CMS for Video"?
Ray Maxwell
_______________________________________________
Do not post admin requests to the list. They will be ignored.
Colorsync-users mailing list (email@hidden)
Help/Unsubscribe/Update your Subscription:
email@hidden
This email sent to email@hidden
Simon Minshall
Acmeworks Digital Film
email@hidden
_______________________________________________
Do not post admin requests to the list. They will be ignored.
Colorsync-users mailing list (email@hidden)
Help/Unsubscribe/Update your Subscription:
This email sent to email@hidden