[opendtv] Re: New Chips Improve Color TV Dramatically

  • From: Doug McDonald <dtvmcdonald@xxxxxxxxx>
  • To: opendtv@xxxxxxxxxxxxx
  • Date: Fri, 2 Jul 2004 13:13:26 -0700 (PDT)

--- jeroen.stessen@xxxxxxxxxxx wrote:
> Hello,
> Doug McDonald has said some very interesting things:
> You can never do a correct colour calibration for a
> wide-gamut display based on the cutoff method. You
> can only do it with a professional colour analyzer !

Well, yes, with, saturated bars. However, for each
sort of physical color primary set (i.e. for each type
of display) a special set of bars can be made so that
the filter comparison method works.

> If we may assume that Doug has calibrated his
> display
> with the (D)VE disc and the filter(s), then he has
> actually calibrated it wrong. He will be rewarded
> with a slightly over-saturated picture. This may be
> pleasing for him, but it is not "correct" !

That's correct ... the green should be and is 
oversaturated, and yellows should look a teensy bit
greenish. This actually happens. You can, of course,
adjust the tint to make skin tones correct if you
But skin is red enough not to matter. 

But on my set, which came with a horrendous red
push, if is plenty good enough just to remove the red 
push and then use the "Joe Kane" method. Theoretically
you should replace the red push with a green cut to
counteract the over-saturated primaries. I think this
is possible with my set.

> Disclaimer: I may have a wrong interpretation of the
> method of calibrating the saturation with the SMPTE
> colour bar picture.

I think you are correct.

Doug McDonald
my last name at scs dot uiuc dot edu, not here at Yahoo, please

Do you Yahoo!?
Yahoo! Mail - 50x more storage than other providers!
You can UNSUBSCRIBE from the OpenDTV list in two ways:

- Using the UNSUBSCRIBE command in your user configuration settings at 

- By sending a message to: opendtv-request@xxxxxxxxxxxxx with the word 
unsubscribe in the subject line.

Other related posts: