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CHROMiX ColorNews Issue #63 - SCCA - Substrate-Corrected Color Aim

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Type: ColorNews
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  CHROMiX ColorNews
   Issue # 63 - April 11th, 2018

This Month's Contents

  1. CHROMiX News
  2. Latest blog entries in ColoRants (and Raves)
  3. Shows and Events
  4. Color Industry News
  5. Forum Topics, Random Bits, etc.
  6. Article - SCCA - Substrate-Corrected Color Aim
  7. CHROMiX Open Box items for sale
  8. ColorNews Admin (feedback, subscriptions, etc.)

CHROMiX Blog
For the very freshest color updates, check out our blog Colorants (and raves).

Respond & Discuss
Don't forget, you can discuss this month's article and anything else from this newsletter in ColorForums.com

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Find full details about subscriptions, etc at the end of this newsletter.

CHROMiX News What the heck have we been up to?

Maxwell Client 5.6 released

We've just release version 5.6 of the Maxwell Client and with it, a bunch of new features and fixes:


  • eXact: spot AND scan over USB OR Bluetooth (as available on eXact)

  • SpectroDens: spot AND scan over USB OR Wifi (as available on Dens)

  • Color Sentenel's CSS-110: spot support on Windows only over USB or Bluetooth, until new drivers arrive

  • FD-9 over Ethernet: share the great device with others on the network

  • instruments can now be locked out of measurements if M0-M3 set as required in Maxwell's Reference Set

  • new instruments menu and preferences pane for configuring instrument connections: yyyyy

  • multi-printer support for reports: use labels and reports

  • Quick hint: double click Tracks (start measuring) or Color Instruments (fire up AutoScan) in the sidebar

Overdue Measurement Notifier - new in Maxwell

Maxwell customers are now able to tell when no activity occurs for their devices and tracks. The new notifier is called 'Measurements Overdue', and is deployable at 2 day, 1 week or 1 month intervals.

The foundation of a viable Quality Assurance or Quality Conformance program relies on consistent measuring. Good measurements equal good reporting. But what can an administrator do when someone isn't measuring?

We feel many Maxwell customers will benefit and find this notifier useful. Try it, and let us know what you think!

Curve4.2 now in beta

The next release of Curve4 is almost out the door.

It incorporates all the new measurement options mentioned above (eXact, SpectroDens, etc) as well as a number of fixes and tunings.

If you'd like to help test it with your instrument, please contact us at help (at) chromix.com and we'll send you a link. We expect it to ship by the end of the month.

CHROMiX welcomes Natalie Upton

Natalie will be adding her talents and creative energy to our social media and public facing efforts. In fact, as her first course of action, she gave us a deadline and helped organize this ColorNews Issue #63. That is no small feat!

Natalie has the same last name and yes, she is Steve's daughter. She is a welcome addition to the CHROMiX team.

CHROMiX LinkedIn page

Check out the latest with our newly refreshed LinkedIn page

CHROMiX Web Resources

Did you know that CHROMiX regularly hosts and contributes to several great informational web sites about color?

Check out the sites for ColorSmarts, ColorWiki and the CHROMiX Blog:

ColorWiki is a deep and robust encyclopedic reference database that hosts CHROMiX software user manuals, Color Management related articles, Color Science/Theory, a Color Glossary, Industry Standards, Test Images, and much more.

ColorSmarts is a great place to get access to past ColorNews issues. It also has a few useful tips and tidbits.

The CHROMiX Blog is a great place for occasional CHROMiX announcements, practical information, and color-related news.

Enjoy. Please let us know how we can improve.

 

CHROMiX Blog Here are some of the recent posts to our blog: Colorants (and raves)

Shows and Events Color-relevant gatherings to plan for

May 7th - 8th, 2018 - InfoFLEX 2018 and Form, Indiana Convention Center, Indianapolis, IN. Package printing and converting technologies show-cased.

May 21st - 23rd, 2018 - WFX: Wide-Format Exchange, Minneapolis MN

September 25th - 27th, 2018 - Labelexpo Americas 2018, Donald E. Stephens Convention Center, Rosemont, IL.

September 30th - October 3rd, 2018 - PRINT 18, McCormick Place South, Chicago, IL

October 18th - 20th, 2018 - SGIA 2018, Las Vegas Convention Center, Las Vegas, NV. Largest premier trade show for the printing industry in North America. Products and technology ranging from dye-sublimation, screen print, packaging, wide-format, grand-format, traditional litho, label and much more.

October 25th - 27th, 2018 - PHOTOPLUS EXPO, New York, NY

Events Calendar: For all current and future events, bookmark this calendar.

Color Industry News What's going on in the world of color

basICColor introduces cockpit

basICColor cockpit integrates spectral images into an ICC workflow. Additionally, cockpit sorts images in collections by color model, and also allows for immediate control of all steps in a color transform. This diverse utility also soft-proofs images, shows out-of-gamut colors, allows numerical control of color shifts during conversions, and more.

EIZO ColorEdge CG247x Certified for Soft-Proofing

Idealliance Certifies the EIZO ColorEdge CG247x, (a 24-inch LCD color critical monitor) for soft-proofing. They also specifically analyzed the accuracy of the CG247x to the CRPC6-GRACoL 2013 reference dataset. CHROMiX is not surprised; we have long felt that the ColorEdge CG247x is the best 24" color critical monitor in the world for graphics. Find it at CHROMiX!

New Eizo LCD reduces eye fatigue, eyestrain

Eizo introduces the FlexScan EV-2455, a 24-inch nearly flicker-free monitor that reduces eye fatigue and helps prevent eyestrain. This device is perfect for viewing documents and for accompanying a ColorEdge-level Eizo like the CG247x referenced above. For more information, here are the specifications for the EV-2455-BK at CHROMiX.

pdfToolbox v10 released in April

Callas is reportedly releasing its newest version of 10 pdfToolbox in April. If you are an eager user, you can join the pre-launch party in Berlin, Germany, on April 12-13, at Pfefferwerk (located in Schonhauser Allee 176 in Berlin, Germany). The sessions will start at 10:30 AM on April 12 and end at 4 PM on April 13.
The official launch is targeted for April 24, and there is a grace period that starts from February 5, 2018, for customers who recently purchased to upgrade free.

Touch7 Photo NEON and ECG released

Touch7 Photo NEON is a Photoshop plug-in that will isolate C, M, and Y components in RGB images, then extract and provide up to 3 new neon fluorescent colors. In a similar fashion, Touch7 Photo ECG isolates and extracts more extended color gamut colors for extended gamut images. New from Color-Logic, the metallic printing technology company.

X-Rite discontinues several legacy instruments

Effective April 27, 2018, X-Rite will discontinue the 504, 508, and all variations of the DensiEye 100. A replacement device will soon be announced. Service and support will continue for a period of 7 years after the stop ship date, with the exception of obsolescence. Instrument upgrades from 504 to 508 will continue to be provided for 12 months after the stop ship date.

Forum Topics and other bits  Popular topics from ColorForums.com and other things we've found along the way.

Changing Color On-Demand:   New 3D-printing technology might soon allow a user to change colors on fabrics on-the-fly with ultraviolet (UV) and other spectrum light sources.

An Artist's Experience with Fine Art Reproduction:   Our friend and customer, Chris Campbell, recently gave a talk at the PIA 2018 Color Conference in San Diego. This discussion inspired attendees and challenged the usual photographic workflow presumptions. Check out this 13-minute Vimeo video summary overview of his workflow process. Additionally, we enjoyed this 6-minute interview with Cary Sherburne of WhatTheyThink. We think you'll enjoy Chris' refreshing perspective.

Color Viewing Terms and Beyond:   
Thanks to Jason Darrah of Prisco for initiating this next discussion by his inquiry to CHROMiX.

Below are a few terms to ponder. Do you know the differences? Click the link to each to find out.

Color Constancy

Chromatic Adaptation

Contrast effect

Successive contrast

After that exercise, consider yourself ready to read the following article from Eddy Hagen, 'The Uncertainty Principle of Visual Color Evaluations'. Within his article, Eddy references and links to another amazing article titled 'Is 1.0 delta E a "just noticeable difference"?' written by our friend and colleague John Seymour.

This might be a "Mr. Toad's Wild Ride" journey for many of you. Consider it drinking from the proverbial color firehose!


Enjoy!




SCCA - Substrate-Corrected Color Aim from Steve Upton

Substrate Corrected Color Aim (SCCA). It just rolls off the tongue doesn't it?

What is this thing? How does it help? What are its limitations?

Why?

Papers differ in white point. In fact, it's a never ending source of frustration for those in the color standards world. It seems that no sooner do they release a shiny new set of color numbers than the paper they were based upon is discontinued. Just try to buy press paper that's the exact same color as the white in GRACoL 2006. No? Too old? OK, try to buy paper that matches GRACoL 2013's (CRPC6) white point. Oh yeah - also, try to find proofing paper that matches the press paper and the color standard. Oy!

Even if you find press paper that matches, your customer might say they like the coating, or feel, or thickness, or price of another paper that is similar enough for them.

Then they ask if you can hit GRACoL 2013.

"Not at that white point," you could say. However, being difficult rarely wins customers' hearts. What they need is a way to fairly judge your printed color when using their paper choice.

SCCA nudges the white point of the color aim to match your paper's white point. It's a 3D fudge factor to help out in the conformance department. The calculated color difference (delta-E) between your paper and your color aim becomes 0, and you're finally being judged by the merits of your printing, rather than the customer's choice of paper.

Issues?

Of course, as this is the world of color, after all.

SCCA's scaling does a remarkably good job of matching up substrate values. In the process, all colors in the converted set are shifted relative to the new white. Imagine a tent pole tilting and shortening / lengthening (darker / lighter) as required to get the tip of the pole in the desired position. The entire tent leans over with the bottom of the pole as the pivot point (more on that below).


Color Error - No SCCA applied to Color Aim



Color Error - SCCA applied to Color Aim

Don't forget that the edges of the diamond-shaped tent (the printing gamut) also tilt. Let's say our tent shifts over toward the blues. If you can imagine the entire tent leaning toward blue, you can see that the cyan edge dips down while the magenta edge lifts up. "Wait!" you say, "Does this mean that the Lab color values of the 100% cyan and 100% magenta patches of my color aim change?".

Yes.

"Hang on, you're telling me that with SCCA the GRACoL 2013 Lab color aim values that we shoot for in proofing and in production change?"

Yes.


Yellow aim shift via SCCA


This is why it's recommended that you only use SCCA when the white point of your measurements differs from your color aim by a reasonably small amount (somewhere less than 3-4 dE2000).

"This sounds like the Relative Colorimetric rendering intent in ICC profiles", you might say.

Indeed, it does. In fact, it's the same mathematical transformation which is documented in the appendix of the ICC specification, and which is used when preparing color measurements for the calculation of ICC profiles. I called SCCA "relative-colorimetric delta-E" before the term SCCA came to the fore.

History

I've heard a couple different stories about where the phrase SCCA originated, but the one I believe is about measurement backing. In the color management world, measurements for building ICC profiles are usually taken over white backing. The press sheet is either placed on a pile of blank sheets or placed on a white measurement table. In production, especially with double-sided printing, a black backing is often used to minimize the effect of print on the back side.

But what do you do with black-backing measurements when you want to create an ICC profile? You can use them, but the white point tends to be darker than desired, and this will show up in proofing when simulating that white on your proofing system. So, a relatively simple calculation is performed to shift the white point from its darker level up to the measurement value seen when the paper was media or white backed.

This method is simple, relatively straightforward, and saves time and effort.

Under the hood

Calculating SCCA is pretty straight-forward. As you may recall, spectral measurements are converted to XYZ values, which are then converted to the Lab values we use for delta-E calculations, graphing, and impressing friends at cocktail parties. If you're handed Lab color values, such as GRACoL 2013, they can be converted back to XYZ, if needed. The SCCA calculation works in XYZ space.

With SCCA, the color aim's white point is moved to your paper's white point, not the other way around. Does it make much difference? Not really, but it does leave your measured colors alone so the reporting of the colors (density, Lab values, etc.) can all be unchanged.

How?

Although SCCA's calculations aren't too complicated, you're likely to perform them in a color management tool of some sort.

CHROMiX's Curve4 can use SCCA when evaluating color for G7 Targeted and ColorSpace certification in the Verify and Calibrate tools. Its new Blend tool also includes a white point mapping function that allows the shifting of measurement white points to any aim value you like.

Maxwell will also soon support SCCA (coming in April 2018). SCCA can be enabled for any metric, allowing some metrics to use SCCA and others to keep an eye on your substrate color. So, you can judge your color's conformance to GRACoL or FOGRA numbers while ensuring that the paper used in the process doesn't shift along the way.

How does SCCA affect G7?

When it comes to G7 Grayscale, SCCA doesn't have an effect. G7 calibration has always been a media-relative process. The G7 idealized curves are scaled to your paper's white point and your printing process's black point. Then all curve calculations are built for your paper. I guess you could say that G7 has SCCA under the hood.

Now that Idealliance has added G7 Targeted and G7 ColorSpace to its certification levels (adding paper / solids and full IT8 patch sets to the testing, respectively), SCCA definitely plays a role. So in G7 conformance tools like Curve4 Verify, SCCA is an available option, but only affects the calculations and pass/fail grading of Targeted and ColorSpace, not Grayscale.


Curve4 VERIFY Tool - No SCCA applied



Curve4 VERIFY Tool - SCCA applied

Implications

Am I compliant when using SCCA?

That is a good question. G7 Master certification allows for SCCA color matching but changes the certification level to "Relative".

Other conformance programs may or may not allow for SCCA. If you submit measurements to obtain some type of certification, you will want to confirm that the agency allows the use of SCCA, and ensure you notify them that SCCA was used to verify the measurements in your submission. Otherwise, they'll likely do absolute comparisons, and your submission may fail.

So, beware. As with many things in life, communication plays a big role.

What about spot & brand colors?

Another good question. In many cases, testing of spot colors is NOT done in a media-relative way, so SCCA does not apply.

If you want to use SCCA, remember that a media white measurement is required for both the color aim set of patches as well as the sample set.

In conclusion

SCCA is a powerful tool to help adjust your systems to evaluate your printing fairly when doing conformance testing. It pays to use it carefully, and not expect miracles when your media white differs significantly from your color aim.

Thanks for reading,

Steve Upton

   To read this article with images in ColorWiki, click here

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Entire Contents of CHROMiX ColorNews (c)2018 CHROMiX, Inc. CHROMiX, Maxwell, ColorThink, ColorNews, ColorSmarts, ColorGear, ColorForums, DisplayWatch and ProfileCentral.com are trademarks of CHROMiX Inc. All other trademarks are property of their respective owners. CHROMiX ColorNews is intended as an informative update to CHROMiX customers and business associates. We are not responsible for errors or omissions. You may not copy or reuse any content from this newsletter without written permission from CHROMiX, Inc.