The issue of color management for HDTV is an interesting topic. I'd
like to take a few moments to give you some background that relates to
why you don't find "color management" and particularly why you don't
find ICC color management in general practice in this industry.
Point 1. Signals that have been encoded to HDTV standards are what is
termed "output referred" . In the case cited by Ray Maxwell, his Canon
HV20 has performed all the color management for the signal prior to the
HTDV encoding. The signal is generally encoded, compressed and
delivered in a YCC-4:2:2 format. There's not much room for massive
transformations because the encoding has been performed rather
agressively. The HDTV standards basically set all the colorimetric and
photometric standards that are necessary for this encoding practice.
ICC technology has been generalized to provide a robust mechanism for
taking data from various source technologies, rendering those images
into a common Profile Connection Space, and then outputting that data
into an arbitrary output space dictated by an output device. If you are
capturing a scene from video for reproduction in another medium, I would
recommend using the new ICC sRGB perceptual rendering profile. Go to
www.color.org and post a question to Phil (see ask Phil) and ask about
the status of this work.
Point 2: Now we ask a simple question, "Why can't we calibrate a display
and use an ICC profile to display to the screen?". If you are going
video to video, the trip through the PCS is quite unnecessary. If you
are working in a known color space, such as the one described by HDTV
standards, the ICC technology is not really useful UNLESS you want to
take a video image to paper or potentially record the video frames on to
film. Here, the technology based offered by ICC technology is quite
useful. If you are simply moving an HDTV image from file, or stream to
display, then the display should be calibrated to match the HDTV
standards. I believe that these are defined as REC 709 primaries, D65,
gamma 2.4 (this possibly wrong, as I don't have the standard in front of
me), and a defined encoding dynamic range (Once again I apologize, I am
at home and don't have access to the standard). Essentially, this is the
sRGB specification with a slightly different gamma. There is a lot of
change going on in this area, and things may change shortly. The big
problem on a computer system is that video path through the display card
is not necessarily the same path used for images written into the normal
display buffer. If you calibrate your display using standard products
which use the LUTs, you may be disappointed to note that they are not
used in the video path. This is very hardware dependent. Therein lies
the biggest issue: We can sell hardware and software solutions, but
there is no guarantee that any of it will be useful on a particular
Point 3. To circumvent these pit falls, specific displays have been
designed to be calibrated outside of the OS to display the HTDV image
correctly. See: http://www.cine-tal.com
This is a display that contains the calibration routines and interfaces
to an i1Display directly. There are other offerings as well. Displays
such as the high end Eizo displays and offerings from HP and NEC can be
set up to a specific color standard based upon internal luts and the
graphic scalar used in the display. These displays can be used, but the
end-user has to be guided through the setup.
We do have a team within X-rite taking a careful look at this industry
and we continuously meet with the manufacturers of hardware and software
to get a better sense of the products that are required to fulfill the
needs of this industry. The complication comes from the wide range of
hardware, software, and non-standard workflows employed currently in the
industry. From my own personal perspective, I believe that offerings
which allow the color management of video images to be performed in the
display rather than the video card, should be the direction the industry
takes. The VESA DDC specs take us to this point. Now if we only could
reliably talk to a display from any operating system.....
Video and Motion Picture Technology
Date: Sat, 02 Jun 2007 23:21:20 -0700
From: Ray Maxwell <email@hidden>
Subject: Color management for HDTV and Final Cut Pro
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Most of us in this group come from a printing and photography
background. However, I have recently made the move to HDTV and have
purchased a Canon HV20 HDV camera. I also have Final Cut Studio 2.
This new software comes with a "Color" application.
With that background...Let me tell you my experience.
There is no mention of computer monitor calibration or ICC color
management to make your computer monitor match your video monitor.
There is no mention of using any of the tools like EyeOne monitor
calibration for the HDTV montior. It seems to be an whole new world
that has never heard of color management.
They talk about placing the standard "PLUNGE" color bar pattern and than
adjusting the monitor by eye. This sounds very primitive to me.
Final Cut Pro makes no mention of color management or ICC profiles.
What is going on?
Has anyone else in this group made this transition and could you point
me to a book or tutorial somewhere?
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