Re: Closed Loop Color
Re: Closed Loop Color
- Subject: Re: Closed Loop Color
- From: Johan Lammens <email@hidden>
- Date: Wed, 31 Oct 2001 10:25:35 +0100
- Organization: Hewlett-Packard
email@hidden wrote:
>
Closed loop color is still the right description. It usually is applied to
>
methods where instead of setting your monitor to be accurate, you
>
intentionally misadjust it until it resembles final printed output, so that
>
it can be used to predict future output for this same device. The limitations
>
of this system become quickly apparent:
As usual, the same phrase can mean different things in different contexts. In the
context of HP DesignJet graphics printers like the 2500CP, the 5000ps, or the
10/20/50ps, we have been using "Closed Loop Color" to describe a built-in color
calibration system. It is closed loop in that it prints a calibration pattern on
media, measures the result with an optical sensor, and then calculates and applies
transfer (linearization) functions to compensate for any deviations from the expected
(nominal) response. Works with the built-in/bundled RIPs, and some third party RIPs.
Obviously this has nothing to do with matching monitor to print. The objective is to
keep the device stable through self-calibration, so that ICC profiles can be made
relative to this stable device and do not have to be updated to reflect calibration
changes. The bundled profiles have been made that way, for each supported
ink/media/printmode combination.
Johan