New IDEAlliance ISO 12647-7 2007 Color Control Strip

raffelj

Member
NOTE: This is a copy of a post made to another list 'printing across boarders [pab]' which I thought this group would be interested in and might be able to comment upon....

Hello and Happy Holidays Group;

I have been following several of the lively discussions in this group with great interest. I can personally attest to the fact that the efforts of the GRACoL committee have created, in addition to lively discussion, a greatly increased interesting in color verification and color process control in the Unites States. (This is a very good thing).

I do, however, have one question for committee members related to the new 126470-7 control strip. Is there a reason the reference data for the strip is not available as spectral reflectance curves?

As the developer of a client/server internet based color verification and process control system which has had paying subscribers for almost four years, and is based entirely upon spectral reflectance data we and our customers would certainly appreciate the availability of the data in such a format.

Because I know the skill level of this group I will save all the preaching about the merits of being able to transform the spectral reflectance results of measurements into alternative angle and observer pairs. Surfice it to say we work with clients across many of the printing processes, and some use alternative angle and oversrver pairs other than D50 / 2 degree. Because of this our spectrally based database hase serverd us and them well.

We are simply trying to prevent having one database structure for reference data (standards either published or self arrived at) and another stucture for the powerful and verstitle measured spectral reflectance vaules.

I look forward to any response and again with everyone a Happy Holiday Season!

Jim Raffel
CEO - ColorMetrix Technologies, LLC
www.ColorMetrix.com
www.JimRaffel.com
 
Re: New IDEAlliance ISO 12647-7 2007 Color Control Strip

>Is there a reason the reference data for the strip is not available as spectral reflectance curves?

Hi Jim,

I don't speak for the decision makers in this regard, but I believe the reason is possibly two fold. One being that the user Iis handed off only XYZ/Lab as the target, and restricted from the ability to inadvertantly or intentionally alter the illuminate or observer angle and thus inadvertantly or intetionally skewing the results. And secondly, that the user is handed a more widely usable format, as not all software will allow use of spectral data, and then it would be up to the user to export Lab via another application, and possibly make incorrect choices regarding observer angle and illuminant. I'll agree that I prefer spectral data when available though, as it is more versatile. That said, I'm not aware of any publically available"official" characterization data that offers spectral reflectance curves.
 
Re: New IDEAlliance ISO 12647-7 2007 Color Control Strip

Hey Jim,

thinking about this awhile brought up some question of my own. If your customers are using alternate angle and illuminants and want to utilize the spectral data for the ISO 12647-7 control strip, what are they using to as a destination profile to begin with? Since the Gracol and SWOP data (TR006, TR003 and TR005) are released as XYZ/LAB data only, how would having the ability to alter the angle and illuminant of the control strip target be beneficial as you would no longer be comparing apples to apples. Or are we not talking about a proofing scenario here?
 
Re: New IDEAlliance ISO 12647-7 2007 Color Control Strip

Hello Mike,

Sorry for the misunderstanding, let me explain. Our database supports only spectral reflectance data - period. So, our customer gets to decide upon the appropriate angle observer pair. Our customers who want to use ProofPass.com with the new control strip would not do so outside the D50 / 2 degree world (at least not with the GRACoL reference data).

Also, for process control purposes most of our customers use whatever methodology is appropriate to set-up their device, and then use actual measured data from that device as the reference. In the process control world utilizing an arbitrary reference point (I am not slamming GRACoL here OK) as opposed to one actually achieved and produced on that device can be a very dicey affair.

So, our use of the catch phase 'color certification and process control' relates to the end-user's reference point. My understanding is GRACoL will have a very powerful internet based certification engine (I believe based upon the Chromix Maxwell engine) to definitively confirm any single proofs conformance to GRACoL.

Most of our users make lots and lots of proofs that have no need for external certification. (I know you understand this as a very longtime ColorMetrix user). One prime example is scatter proofs for internal consumption. It is still a good idea we know these are good proofs, but we sure don't need to upload the data for every scatter to GRACoL for confirmation. (at least I would not do it that way)

I hope this clears things up.
 
Re: New IDEAlliance ISO 12647-7 2007 Color Control Strip

>Our database supports only spectral reflectance data - period. So, our customer gets to decide upon the appropriate angle observer pair. Our customers who want to use ProofPass.com with the new control strip would not do so outside the D50 / 2 degree world (at least not with the GRACoL reference data).

Ok. Makes sense and I see your dilema. However, since the Gracol/SWOP data is somewhat synthetic, and based off Fogra39, I doubt that spectral data relating to the released data sets and control strip even exist.

>In the process control world utilizing an arbitrary reference point (I am not slamming GRACoL here OK) as opposed to one actually achieved and produced on that device can be a very dicey affair.

Agreed, and for the most part, that's been our approach as well. There are times when we are required to compare to idealized data, such as TR006 to set someone's mind at ease.
 

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