CCA RIT Team first experiment summary

1

CCA RIT Team first experiment summary

ElenaFedorovskaya,BobChung,DonHutcheson,DavidHunter,PierreUrbainDon'shastyupdate,November13,2018

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Introduction

• RITresearchpromptedbythesevendatasetsinISO/PAS15339-2.TheseCRPCsexhibitconsistentcolorappearancebutthestatementlacksscientificverification.

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CRPC1~CRPC7 CMYK(Pictorial,ISO12642-2)

CRPC1 CRPC2 CRPC3 CRPC4 CRPC5 CRPC6 CRPC7

•  DifferentsubstratesandC*•  SameCMYRGBhueangles•  Sametonereproduction•  Samegraybalance•  Colordifferencesbetweenadjacent

printingconditionsareunequal.•  CCAwasmentioned,butnot

verified.

!5#

!4#

!3#

!2#

!1#

0#

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0# 10# 20# 30# 40# 50# 60# 70# 80# 90# 100#

a*/b*%

%TV%

RPC1_a# RPC1_b# RPC3_a# RPC3_b#

RPC5_a# RPC5_b# RPC7_a# RPC7_b#

!5#

!4#

!3#

!2#

!1#

0#

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0# 10# 20# 30# 40# 50# 60# 70# 80# 90# 100#

a*/b*%

%TV%

RPC2_a# RPC2_b# RPC4_a#

RPC4_b# RPC6_a# RPC6_b#

CRPC1,3,5,and7 CRPC2,4,and6

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0.1

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0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0 10.0 11.0 12.0 13.0 14.0

∆E00

CRF(CRPC1-CRPC2)

(CRPC2-CRPC3)

(CRPC3-CRPC4)

(CRPC4-CRPC5)

(CRPC5-CRPC6)

(CRPC6-CRPC7)

95th percentile ∆E 00

(CRPC1-CRPC2) 7.24(CRPC2-CRPC3) 6.56(CRPC3-CRPC4) 9.86(CRPC4-CRPC5) 4.18(CRPC5-CRPC6) 3.26(CRPC6-CRPC7) 4.03

0"

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0" 10" 20" 30" 40" 50" 60" 70" 80" 90" 100"

Dk#

%TV#

RPC1_Dk"

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RPC7_Dk"

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0" 10" 20" 30" 40" 50" 60" 70" 80" 90" 100"

Dk#

%TV#

RPC2_Dk"

RPC4_Dk"

RPC6_Dk"

CRPC 1, 3, 5, and 7! CRPC 2, 4, and 6!

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Dk#

%TV#

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RPC7_Dk"

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0" 10" 20" 30" 40" 50" 60" 70" 80" 90" 100"

Dk#

%TV#

RPC2_Dk"

RPC4_Dk"

RPC6_Dk"

CRPC 1, 3, 5, and 7! CRPC 2, 4, and 6!

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Objectives

•  TestthehypothesisthatCCAdependsonmultipledatasetswithvaryinggamutvolumes,whilehavingconsistenttonality,graybalanceandhuesrelativetosubstrate.• Examinethesuitabilityofthe95thpercentile∆E00asaCCAmetric•  3∆E00(95thpercentile∆E00)colordifferencebetweenadjacentdatasetsintheControlandtheExperimentalgroups.

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Experimental — Sample Preparation •  UseCRPC5asastartingpointtocreate7datasetsdifferinginchromaandgamutvolumeby3∆E00at95%pctl.(Controlgroup).

•  Createsystematicallydistorteddatasetsintermsof•  graybalance•  tonereproduction•  chroma(gamut)

•  Differences3∆E00at95%pctl.(Experimentalgroup).

TR-1TR-2TR-3 TR+1 TR+2 TR+3

RefCRPC

Ch+1

Ch+2

Ch+3

Ch-1

Ch-2

Ch-3

GB+1

GB+2

GB+3

GB-1

GB-2

GB-3

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Control Group

CMYK(Pictorial,ISO12642-2)

Ch-3 Ch-2 Ch-1 CRPC4 Ch+1 Ch+2 Ch+3

•  DifferentC*andgamut•  SameCMYRGBhueangles•  Sametonereproduction•  Samegraybalance•  Colordifferencesbetweenadjacent

printingconditionsareequal.

• ReplaceCRPC1~CRPC7inpsychometrictesting

95th ∆E00 -3d_G7 -2d_G7 -1d_G7 0d_G7 +1d_G7 +2d_G7 +3d_G7

-3d_G7 -----

-2d_G7 3.1 -----

-1d_G7 6.2 3.1 -----

0d_G7 9.2 6.2 3.1 -----

+1d_G7 12.3 9.3 6.2 3.1 -----

+2d_G7 15.2 12.2 9.2 6.2 3.1 -----

+3d_G7 16.8 13.8 10.8 7.9 5.5 3.0 -----

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Experimental Groups CMYK(Pictorial,ISO12642-2)

TR-3 TR-2 TR-1 CH+2 TR+1 TR+2 TR+3

•  SameC*andgamut•  SameCMYRGBhueangles•  Differenttonereproduction•  Samegraybalance•  Colordifferencesbetweenadjacentprinting

conditionsareequal.

CMYK(Pictorial,ISO12642-2)

GB-3 GB-2 GB-1 CH+2 GB+1 GB+2 GB+3

•  SameC*andgamut•  SameCMYRGBhueangles•  Sametonereproduction•  Differentgraybalance•  Colordifferencesbetweenadjacentprinting

conditionsareequal.

95th ∆E00 3Y 2Y 1Y 0 1B 2B 3B

3Y -----

2Y 3.0 -----

1Y 6.1 3.0 -----

0 9.1 6.1 3.0 -----

1B 12.2 9.1 6.1 3.0 -----

2B 15.2 12.1 9.1 6.1 3.0 -----

3B 18.1 15.1 12.1 9.1 6.0 3.0 -----

95th ∆E00 -3TVI -2TVI -1TVI 0 +1TVI +2TVI +3TVI

-3TVI -----

-2TVI 3.0 -----

-1TVI 6.1 3.0 -----

0 9.0 5.9 3.0 -----

+1TVI 12.0 8.9 6.0 3.0 -----

+2TVI 14.9 11.9 8.9 6.0 3.0 -----

+3TVI 17.7 14.9 11.9 9.0 6.0 3.0 -----

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Experimental — Sample Verification

•  Verifyalldatasetandprofiles(AnnexC)•  Applyprofilestotestimagesandoutputhardcopy,perflowchart.

• MeasurehardcopiesoftheIdealliance12647-7digitalcontrolstrip(84patches)andcalculatethe95thpercentile∆E00betweenadjacentdatasets.

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Experimental — Psychometric Testing 1

•  Thereisa‘hole’intheControlgroup.Rankthecandidateimagesthatexhibit(fromthemosttotheleast)consistentcolorappearanceinrelationtotheControlgroup.

Controlgroup

CandidateImages(randomized)

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Visual Variation Between Datasets

•  Thenextfiveslidesvisualizethesevenbasicdatasets,andthedistorteddatasets(TVI,Contrast,Graybalance,Chroma)• Eachdatasetineachgroupdiffersfromit'sneighbourby3∆E0095thpctl.•  Theleftimageisanominalreference

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7 datasets

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TVI

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S-curve

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Graybal

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Chroma

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Experimental — Psychometric Testing 2

or

or

Whichsetinpairhashigherconsistencyofcolorappearance?Providerating1-excellent,2-good,3–fair,4–poor,5-unacceptable

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Results — Sample Verification

•  Visualsimulationmeetsexpectations.

•  Theaverage95thpercentilecolordifferencebetweenadjacentdatasetsintheControlgroupis3.1∆E00.

•  Theaverage95thpercentilecolordifferencebetweenadjacentdatasetsintheExperimentalgroupis3.0∆E00.

•  Theaverage95thpercentile∆E00betweentheControldataset(2d_G7)andgraybalancedistortedgroupis3∆E00,6∆E00,or9∆E00.

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Results — Visual Simulation • Controlgroupvs.CRPC1~CRPC7

7newdatasetsfromCRPC5byscalingwhitepoint,blackpointandchromawithconstantprimaryhueangles,G7tonalityandgraybalance,withthe95thpercentile∆E00betweenanytwoadjacentdatasets=3

VisualsimulationoftheControlgroup(-3d~3d)

VisualsimulationoftheCRPCs(CRPC1~CRPC7)

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Results — Visual Simulation • Experimentalgroup(tonalcurveshapevs.TVI)

12datasetsvaryingintonality(3lighter,3darker,3lowercontrast,3highercontrast)and18datasetswithgraybalance(3each+CMYRGB)variationsfromonereferencecontroldataset,with395thpercentile∆E00betweenanytwoadjacentdatasets.

•  VisualsimulationoftheExperimentalgroup(S-3toS+3)

•  VisualsimulationoftheExperimentalgroup(TVI-3toTVI+3)

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•  VisualsimulationoftheExperimentalgroup(GB_C-R)

•  VisualsimulationoftheExperimentalgroup(GB_M-G)

•  VisualsimulationoftheExperimentalgroup(GB_Y-B)

• Experimentalgroup(graybalanceincomplementaryhueangles)

Results — Visual Simulation

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Results — Analysis of the Experimental Group

• 2dvs.GB_C1(B1,G1,M1,R1,Y1areomitted.)•  95thpercentileCRF:3.1∆E00

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R G B C M Y Ref Sample

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%DotArea

2d_G7(dash) GB_C+1(solid)

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Z) T

VI

% Dot

Ref_C Ref_M Ref_Y Ref_KSample_C Sample_M Sample_Y Sample_K

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• 2dvs.GB_C2(B2,G2,M2,R2,Y2areomitted.)•  95thpercentileCRF:6.1∆E00

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2d_G7(dash) GB_C+2(solid)

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Z) T

VI

% Dot


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• 2dvs.S+1(S-3,S-2,S-1,S+2,S+3areomitted.)•  95thpercentileCRF:3.0∆E00

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2d_G7(dash) S+1(solid)

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% Dot


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Results —95th ∆E00 of Adjacent Datasets

•  Experimentaldatasets(GB_3Y~3B)

•  ‘0’represents‘+2d_G7’

95th ∆E00 3Y 2Y 1Y 0 1B 2B 3B

3Y -----

2Y 3.0 -----

1Y 6.1 3.0 -----

0 9.1 6.1 3.0 -----

1B 12.2 9.1 6.1 3.0 -----

2B 15.2 12.1 9.1 6.1 3.0 -----

3B 18.1 15.1 12.1 9.1 6.0 3.0 -----

95th ∆E00 -3TVI -2TVI -1TVI 0 +1TVI +2TVI +3TVI

-3TVI -----

-2TVI 3.0 -----

-1TVI 6.1 3.0 -----

0 9.0 5.9 3.0 -----

+1TVI 12.0 8.9 6.0 3.0 -----

+2TVI 14.9 11.9 8.9 6.0 3.0 -----

+3TVI 17.7 14.9 11.9 9.0 6.0 3.0 -----

•  Experimentaldatasets(-3TVI~+3TVI)

•  ‘0’represents‘+2d_G7’

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Results — Psychometric Testing

• Viewingbooth(gti;ISO3664-2009compliant)• 6Samplesets• 2sessions• 12participants•  6experts•  6novices

Controlset

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Results — Psychometric Testing

1)  RanksamplesthatfitintheimagesetforbestCCA

2)  CompareandratesamplesetsfordemonstratingCCA.

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Results: CCA from ranking images for the best corrected

-3.00 -2.50 -2.00 -1.50 -1.00 -0.50 0.00 0.50 1.00

CCAbasedonrankingcandidateimages

G7+2d

R+1

Y+1

G+1

TVI-1

TVI+1C+1

S-1S+1B+1

TVI-2S-2G+2 S-3

TVI-3M+2S+2

B+2

R+2TVI+2

M+1C+2

ColorConsistencyscalebasedonThurstone’sLawofComparativeJudgement,CaseV(Thurstone,1927)

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Results: CCA vs measured adjacent 95% delta E00

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Results: Measured 95% delta E00 vs relative CCA

30Results: Consistency of Color Appearance from Ratings of Sets of Images

LSMeans Differences Tukey HSDα= 0.050 Q= 2.8654

LevelGB Y-BGB M-GGB C-RSTVIControl

AAA

BBB

CC

LeastSq Mean

3.623.403.133.032.422.32

Levels not connected by same letter are significantly different.

11.5

22.5

33.5

44.5

5

Sco

re L

S M

eans

Con

trol

GB

C-R

GB

M-G

GB

Y-B S

TVI

Set

Source

Nparm DF

Sum of Squares F Ratio Prob > F

Set 5 5 81.914 15.301 <.0001*

All12participants

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LevelGB Y-BGB M-GGB C-RSTVIControl

AA

BB

CC

D

E

LeastSq Mean

4.134.073.433.232.531.70


Results: Comparison of Consistency of Color Appearance Ratings for Sets of Images

Source

Nparm DF


Set 5 5 131.117 31.723 <.0001*

EXPERTSONLY(6participants)

11.5

22.5

33.5

44.5

5

Sco

re L

S M

eans

Con

trol

GB

C-R

GB

M-G

GB

Y-B S

TVI

Set

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LevelGB Y-BControlGB C-RSGB M-GTVI

AAAAA

BBBBB

LeastSq Mean

3.102.932.832.832.732.30


Results: Comparison of Consistency of Color Appearance Ratings for Sets of Images

Source

Nparm DF


Set 5 5 10.911 2.358 .0423

NOVICESONLY(6participants)

11.5

22.5

33.5

44.5

5

Sco

re L

S M

eans

Con

trol

GB

C-R

GB

M-G

GB

Y-B S

TVI

Set

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Conclusions •  AmethodologyforstudyingConsistentColorAppearanceforasetofprintedimageswasdeveloped.

•  PsychometrictestsshowedthatCCAofimagesetwithchromachangesappeartobemoreconsistentthanduetootherattribute(+/-TR,+/-GB)change.

•  ThereisadiscrepancybetweenexpertsandnoviceswhenjudgingCCAwhichmaybeattributedtotheCCAversusimagequalityperceptions.

•  LargerangeofimagevariationswithinasetcanbeproblematicforjudgingCCA.•  Device-based95thpercentile∆E00isshowntobeagoodpredictorforConsistentColorAppearanceinthepresentexperiment.The95thpercentile∆E00~3wereperceptibleintermsofCCAevaluations.

•  AdditionalexperimentsareneededtoevaluatetheeffectsofpictorialsceneonCCA.

Documents

CCA RIT Team first experiment summary