[Openicc] [argyllcms] Re: Helping with colord

[Hal V. Engel]

On Monday, March 07, 2011 02:39:13 PM edmund ronald wrote:
> compelled - hah! :)
> and what instrument do you expect your average Taiwan corp will use to
> measure the primaries ?
> not only that, but my experiments a year ago indicated that many
> laptops cannot get the EDID data from an attached monitor under
> Windows, because the driver has not implemented this data channel. I
> don't know how it is with Linux.

This is also the case on X11 systems at least for some drivers/hardware. 

> 
> Edmund
> 
> On Mon, Mar 7, 2011 at 10:56 PM, Chris Murphy <lists at colorremedies.com> 
wrote:
> > Historically that has been expensive. At least if the filters are both
> > accurate and consistent unit to unit. My preference is that
> > manufacturers be compelled, one way or another, to insert the correct
> > information in EDID. And then users don't have to deal with it at all.
> > 
> > We do have the small problem of backlight decay over time.
> > 
> > Chris
> > 
> > On Mar 7, 2011, at 2:33 PM, edmund ronald wrote:
> >> Chris,
> >> 
> >> As usual, you have hit the nail on the head, colorimeters are not
> >> going to be much fun when the primaries are spiky and unknown.
> >> I knew this when I did my colorimeter design.
> >> But I think a low-cost spectro will not be very happy with spiky LEDs
> >> either. I think the only really reliable way to measure a color LED
> >> backlight panel is probably a really good high-end filter instrument..
> >> There is an ex-east german company which I believe has an accessible
> >> colorimeter with "real cone" RGB filters.
> >> 
> >> 
> >> Edmund
> >> 
> >> On Mon, Mar 7, 2011 at 9:51 PM, Chris Murphy <lists at colorremedies.com> 
wrote:
> >>> I wish a grant were possible to determine the accuracy of EDID primary
> >>> information. With display technologies all over the map, a colorimeter
> >>> is ill equipped to do a good job all of the time due to mismatching
> >>> primaries to the color matrix in the colorimeter (or its software). I
> >>> am presently unconvinced that most people need a colorimeter in this
> >>> category. It really takes a spectro to be sure. I have seen
> >>> colorimeters, including the Huey, do a worse job than default EDID
> >>> based profiles, with common displays.
> >>> 
> >>> Chris Murphy
> >>> 
> >>> On Mar 7, 2011, at 2:24 AM, Richard Hughes wrote:
> >>>> On 7 March 2011 09:14, edmund ronald <edmundronald at gmail.com> wrote:
> >>>>> Of course I didn't :)
> >>>> 
> >>>> Heh :)
> >>>> 
> >>>>> However the technology and calibration issues are the same as with
> >>>>> any colorimeter; I wouldn't expect any surprises, other than the
> >>>>> perennial matrix issues. In fact, I would expect my design to
> >>>>> perform better than Huey, which at the time I did this was the
> >>>>> low-cost instrument to beat.
> >>>> 
> >>>> Right, and I guess the Huey is still the low cost instrument to beat.
> >>>> It's certainly what I advise people who ask to buy.
> >>>> 
> >>>>> My guess is that the technology I used was intended for, and will be
> >>>>> or is found in some self-calibrating screens, where of course the
> >>>>> calibration issues can be solved at manufacture time, and later by
> >>>>> remeasuring with a spectro.
> >>>> 
> >>>> I guess if someone was to manufacture the devices in small quantity
> >>>> they should just calibrate them at manufacture time with something
> >>>> like a ColorMunki. I assumed you wanted to post the PCB and BOM online
> >>>> and let people make their own colorimeter, open source style.
> >>>> 
> >>>>> I should stress that I did the hardware design myself, and had some
> >>>>> protos fabricated, and wrote the Mac instrument drivers, I did not
> >>>>> write full calibration software.
> >>>> 
> >>>> Right. It sounds like you could commercialize this and make a bit of
> >>>> pocket money, on the assumption you can undercut the huey by a
> >>>> significant enough margin for production volumes < 1000 or so. That's
> >>>> the tricky bit.
> >>>> 
> >>>> Richard.
> >>>> _______________________________________________
> >>>> openicc mailing list
> >>>> openicc at lists.freedesktop.org
> >>>> http://lists.freedesktop.org/mailman/listinfo/openicc
> >>> 
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> > 
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