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Improving Color Matching Using iccMAX Chris Bai, Chief Color Scientist, BenQ Corporation
ImprovingColorMatching UsingiccMAX
ChrisBai,ChiefColorScientist,BenQ Corporation
Overview
• WhatHappened?
• SomeMoreResearch…
• ThePlan
• Result
• Conclusion
• FutureWork
WhatHappened?
• WhenBenQ 1st LEDbacklightcolormanagementmonitorwasannounced in2013.
• Veryexcitingnews!
• ExperiencedusersfoundoutLEDbacklightmonitordidnotperformedwellinsoftproofingscenario.
ExperiencedObserver
???
Symptoms
• Variationsinblue,greenandpaleyellowtones,forexample.
• Differenceinperceivedsaturation.
LEDBacklightMonitor(Simulated)
ViewingBooth(Simulated)
Slighthueshiftinblue
Slighthueshiftingreen
Slighthueshiftinpaleyellow
Overallsaturationisdifferent
WhatwasWrong?
• ΔE00* ismoreorlessthesame…
TestedwithIT8.7/41617Patches:• LEDMonitor:
• Avg.ΔE00* =1.25• Max.ΔE00* =4.35
• CCFLMonitor:• Avg.ΔE00* =1.20• Max.ΔE00* =4.25
Notmuchdifferencefromthevaluesalone.
SomeMoreResearch…
• CIEReport* suggested:“Apotentialpracticalsolutionistoimplementanobserver-dependentcolorimagingworkflowatthedevicelevel.… Conceptuallythisissimilartothedevice-dependentcolorimaging,awell-establishedcolormanagementconcept.“
• Butnospectralcolormanagementworkflowwasestablishedatthattime.
• OnlyStandardObservercouldbeapplied.
*CIEFinalReportforR1-54:VariabilityInColor-MatchingFunctions
ObserverVariations
*Y.Asano,MSCL,RIT,USAhttp://www.cis.rit.edu/~yxa8513/Research.html
ThePlan
• TofindapotentialsolutionforLEDbacklightmonitors(andothernarrowbandwidthdisplaydevices).• Narrowbandwidthdisplaydevicesarebecomingextremelypopularoverthelast2years.
• TovalidateiccMAX frameworkinrealworldapplication.
ExperimentFlow
ObtainIndividualCMF
IncorporateCMFintoDisplayPipeline
PairComparisonExperiment
HopeThisHelps…
SelectObservers12ppl,6Male&6Female,
25~40yearsold
ObtainDataPoints14patches,10° field,
7selections
Connectthe“Dots”Usinginterpretationmethodwith
CIECategorizedObserver
MeasureDisplaySPD’sCCFLv.s.LED
IncorporatingiccMAXDisplaySPD’s&CMF
ValidationTestOriginalPatchSet+TestSet
PracticalTest8 TestImages
MimicCCFLMonitor ImprovingColorMatching
ColorPatchSelection
14Patches
*Y.Asano,MSCL,RIT,USAhttp://www.cis.rit.edu/~yxa8513/Research.html
Categorization
• It’sverydifficultandtimeconsumingtoobtainindividual’sCMF.• Apparatusisalsoanotherdifficulty…
• UsedcategorizedmethodtodetermineCMF:• AssuggestedinCIEFinalReport*
• 14colorpatcheswereusedtodeterminefixeddatapoints
• Interpretationwasusedtoobtaintheintermediatedatapoints
*CIEFinalReportforR1-54:VariabilityInColor-MatchingFunctions
Interface
ExperimentSetup
iccMAX Workflow
DestinationProfileB2D0Tag
SourceProfileD2B0Tag
CalibrationTarget:D65,160cd/m2,Gamma2.2
SpectralProfileConnectionSpace
ObserverCMF
TestImages
TestImage1 TestImage2 TestImage3
TestImage5
TestImage4
TestImage6 TestImage7 TestImage8
Result
TestImage1
BEFO
RE
No.ofAcceptable 7 9 3 4
No.ofUnacceptable 5 3 9 8
RateofAcceptable 58.3% 75.0% 25.0% 33.3%
AFTER
No.ofAcceptable 9 10 8 6
No.ofUnacceptable 3 2 4 6
RateofAcceptable 75.0% 83.3% 66.7% 50.0%
Improvement +16.7% +8.3% +41.7% +16.7%
TestImage2 TestImage3TestImage4
ResultBE
FORE
No.ofAcceptable 4 8 6 5
No.ofUnacceptable 8 4 6 7
RateofAcceptable 33.3% 66.7% 50.0% 41.7%
AFTER
No.ofAcceptable 3 10 9 6
No.ofUnacceptable 9 2 3 6
RateofAcceptable 25.0% 83.3% 75.0% 50.0%
Improvement -8.3% +16.6% +25.0% +8.3%
TestImage5 TestImage6 TestImage7 TestImage8
WhatDoImagesLookLikeforOneObserver?
Before
Original
After
TestIm
age1
Before
Original
After
TestIm
age2
Before
Original
After
TestIm
age3
Before
Original
After
TestIm
age4
WhatDoImagesLookLikeforOneObserver?
Before
Original
After
TestIm
age5
Before
Original
After
TestIm
age6
Before
Original
After
TestIm
age7
Before
Original
After
TestIm
age8
Conclusion
• ImprovementwasshownafterutilizingiccMAX workflow.• Blueandgreentones
• Saturatedcolors
• Someareastillneedsfurtherinvestigation:• Paleandlowbrightnesscolors
• Skintone
• Redtones
• Overall,withproperadjustment,iccMAX isthekeytosolveobservermetamerism onnarrowbandemissiondevices.
FutureWork
1.Moreobserverswithdifferentage,ethicgroups,experiencelevel…
2. Incorporatemorewidegamutdisplayswithdifferentspectralcharacteristics:(Inprogress…)• QuantumDotTechnology
• LaserDiode+LEDTechnology(RedLaserDiode+CyanLED)
• OLED
3. ImprovementonCMFestimation:• ValidatecurrentCMFestimation.
• Abetterfittingalgorithmfor“connectingthedots”.
• Constructarobustandsimplifiedmethodtoestimateindividual’sCMF.
FutureWork
4. Matchingtohardcopiesunderdifferentlightsourcetypes• Fluorescentlight
• LEDlight
ThankYouforYourAttention
