Top Banner
An Interactive An Interactive Perception Based Model Perception Based Model for Characterization of for Characterization of Display Devices Display Devices 1 1 Institute of Computer Graphics and Algorithms Institute of Computer Graphics and Algorithms Vienna University of Vienna University of Technology, Austria Technology, Austria 2 2 Grup de Gr Grup de Gr à à fics de Girona, fics de Girona, Universitat de Girona, Spain Universitat de Girona, Spain Attila Neumann Attila Neumann 1 1 , Alessandro Artusi , Alessandro Artusi 1 , , Georg Zotti Georg Zotti 1 1 , L , L ászló Neumann ászló Neumann 2 2 , , Werner Purgathofer Werner Purgathofer 1 1
23

An Interactive Perception Based Model for Characterization of Display Devices 1 Institute of Computer Graphics and Algorithms Vienna University of Technology,

Mar 28, 2015

Download

Documents

Molly O'Keefe
Welcome message from author
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
Page 1: An Interactive Perception Based Model for Characterization of Display Devices 1 Institute of Computer Graphics and Algorithms Vienna University of Technology,

An Interactive Perception Based An Interactive Perception Based Model for Characterization of Model for Characterization of

Display DevicesDisplay Devices

11 Institute of Computer Graphics and Algorithms Institute of Computer Graphics and AlgorithmsVienna University of Technology, AustriaVienna University of Technology, Austria

22 Grup de GrGrup de Grààfics de Girona, fics de Girona, Universitat de Girona, SpainUniversitat de Girona, Spain

Attila NeumannAttila Neumann11, Alessandro Artusi, Alessandro Artusi11, ,

Georg ZottiGeorg Zotti11, L, László Neumannászló Neumann22, ,

Werner PurgathoferWerner Purgathofer11

Page 2: An Interactive Perception Based Model for Characterization of Display Devices 1 Institute of Computer Graphics and Algorithms Vienna University of Technology,

Attila Neumann Computergraphik @ TU Wien

MotivationMotivation

By human observation

Reliable characterization of display

By a measuring device

Page 3: An Interactive Perception Based Model for Characterization of Display Devices 1 Institute of Computer Graphics and Algorithms Vienna University of Technology,

Attila Neumann Computergraphik @ TU Wien

Colors of the displayColors of the display Additive RGB channelsAdditive RGB channels

characteristics separable by channelcharacteristics separable by channel Side effectsSide effects

slight cross effects (stronger for LCD)slight cross effects (stronger for LCD) environmental effectsenvironmental effects

PipelinePipeline graphics card [byte]graphics card [byte] display device [voltage]display device [voltage] eye [luminance]eye [luminance] brain [color appearance]brain [color appearance]

Page 4: An Interactive Perception Based Model for Characterization of Display Devices 1 Institute of Computer Graphics and Algorithms Vienna University of Technology,

Attila Neumann Computergraphik @ TU Wien

Tone Reproduction CurveTone Reproduction Curve

byte → luminance (by channel)

Page 5: An Interactive Perception Based Model for Characterization of Display Devices 1 Institute of Computer Graphics and Algorithms Vienna University of Technology,

Attila Neumann Computergraphik @ TU Wien

Previous Work – Models for the TRCPrevious Work – Models for the TRC Models with small number of parametersModels with small number of parameters

Linear functions: Linear functions: GOG, version 1.x IEC GGO, version 2.x 3.x IEC GOGO GOG, version 1.x IEC GGO, version 2.x 3.x IEC GOGO [Berns et al. 1993][Berns et al. 1993]

Non linear functions: Non linear functions: LIN-LIN2, LOG-LIN, LOG-LIN2, LOG-LOG, LOG-LOG2 LIN-LIN2, LOG-LIN, LOG-LIN2, LOG-LOG, LOG-LOG2 [Post and Calhoun 1989], [Katoh and Deguchi 1998][Post and Calhoun 1989], [Katoh and Deguchi 1998]

S-curve (S-shaped function): S-curve (S-shaped function): handling cross effect (mainly at LCD monitors)handling cross effect (mainly at LCD monitors) [Kwak MacDonald 2001], [Miyake et al. 1990][Kwak MacDonald 2001], [Miyake et al. 1990]

Arbitrary number of parametersArbitrary number of parameters Masking model Masking model (spline)(spline)

[Tamura et al. 2003] [Tamura et al. 2003]

Page 6: An Interactive Perception Based Model for Characterization of Display Devices 1 Institute of Computer Graphics and Algorithms Vienna University of Technology,

Attila Neumann Computergraphik @ TU Wien

Our methodOur method

Basic measurement stepsBasic measurement steps Human observationsHuman observations

Errors are tolerable and can be reducedErrors are tolerable and can be reduced Relative measurementsRelative measurements

Finding the input values (instead of output values) Finding the input values (instead of output values) Automatic stop and setup of basic stepsAutomatic stop and setup of basic steps

Optimization (definition of the TRC function)Optimization (definition of the TRC function)

Generic function is achievedGeneric function is achieved A relative curve is definedA relative curve is defined Passes requirements of human perceptionPasses requirements of human perception

Page 7: An Interactive Perception Based Model for Characterization of Display Devices 1 Institute of Computer Graphics and Algorithms Vienna University of Technology,

Attila Neumann Computergraphik @ TU Wien

Basic step Basic step

Similar to classic gamma applet

Page 8: An Interactive Perception Based Model for Characterization of Display Devices 1 Institute of Computer Graphics and Algorithms Vienna University of Technology,

Attila Neumann Computergraphik @ TU Wien

Basic step Basic step

Similar to classic gamma applet

Page 9: An Interactive Perception Based Model for Characterization of Display Devices 1 Institute of Computer Graphics and Algorithms Vienna University of Technology,

Attila Neumann Computergraphik @ TU Wien

Basic step Basic step

Similar to classic gamma applet

Page 10: An Interactive Perception Based Model for Characterization of Display Devices 1 Institute of Computer Graphics and Algorithms Vienna University of Technology,

Attila Neumann Computergraphik @ TU Wien

Basic step Basic step

Similar to classic gamma applet

Page 11: An Interactive Perception Based Model for Characterization of Display Devices 1 Institute of Computer Graphics and Algorithms Vienna University of Technology,

Attila Neumann Computergraphik @ TU Wien

Basic step Basic step

Similar to classic gamma applet

Page 12: An Interactive Perception Based Model for Characterization of Display Devices 1 Institute of Computer Graphics and Algorithms Vienna University of Technology,

Attila Neumann Computergraphik @ TU Wien

Basic step Basic step

Similar to classic gamma applet

Page 13: An Interactive Perception Based Model for Characterization of Display Devices 1 Institute of Computer Graphics and Algorithms Vienna University of Technology,

Attila Neumann Computergraphik @ TU Wien

Basic step Basic step

Page 14: An Interactive Perception Based Model for Characterization of Display Devices 1 Institute of Computer Graphics and Algorithms Vienna University of Technology,

Attila Neumann Computergraphik @ TU Wien

Basic step Basic step

Page 15: An Interactive Perception Based Model for Characterization of Display Devices 1 Institute of Computer Graphics and Algorithms Vienna University of Technology,

Attila Neumann Computergraphik @ TU Wien

Basic step Basic step

Page 16: An Interactive Perception Based Model for Characterization of Display Devices 1 Institute of Computer Graphics and Algorithms Vienna University of Technology,

Attila Neumann Computergraphik @ TU Wien

The math problemThe math problem No direct measurements for No direct measurements for f(x)f(x)

onlyonly relative measurements relative measurements ((x((x00, x, x22, r), , r), xx11))

diff = ydiff = y11‘-y‘-y1 1 = r= rf(xf(x00)+(1-r))+(1-r)f(xf(x22)-f(x)-f(x11))

depends on the depends on the unknownunknown y=f(x)y=f(x) TRC TRC

Optimum criteria Optimum criteria for the for the y=f(x)y=f(x) TRC TRC y‘-yy‘-y expressions are to be expressions are to be minimizedminimized

instead of the usual instead of the usual yyii=f(x=f(xii)) i.e. i.e. diffdiffii=0 =0 !!!! other targets can be definedother targets can be defined

smoothness conditionsmoothness condition repeatable measurementsrepeatable measurements

Page 17: An Interactive Perception Based Model for Characterization of Display Devices 1 Institute of Computer Graphics and Algorithms Vienna University of Technology,

Attila Neumann Computergraphik @ TU Wien

The compound minimum problemThe compound minimum problemf(i) [i=0..255] f(i) [i=0..255] are unknownare unknown

Measurement conditions:Measurement conditions:

M(j) = rM(j) = rjjf(lowf(lowjj)+(1-r)+(1-rjj))f(highf(highjj)-f(back)-f(backjj) ) [j=1..N] [j=1..N]

Smoothness conditions:Smoothness conditions:S(i) = f(i+1)+f(i-1)-2S(i) = f(i+1)+f(i-1)-2f(i) f(i) [i=1..254] [i=1..254]

Convex quadratic minimum problemConvex quadratic minimum problem

F = F = i=1..Ni=1..N m mjjM(j)M(j)22 + + i=1..254i=1..254 s siiS(i)S(i)22

Minimized by a conjugate gradient methodMinimized by a conjugate gradient method

Page 18: An Interactive Perception Based Model for Characterization of Display Devices 1 Institute of Computer Graphics and Algorithms Vienna University of Technology,

Attila Neumann Computergraphik @ TU Wien

Additional questionsAdditional questions Setting the coefficientsSetting the coefficients

weightsweights m m and and ss control the behaviour of control the behaviour of ff Definition of triplets Definition of triplets (low(lowii, high, highii, ratio, ratioii))

predefined tripletspredefined triplets optimal ‚next triplet‘, stop criteriumoptimal ‚next triplet‘, stop criterium

defined by the local and/or overall defined by the local and/or overall reliabilityreliability LOG-LOG coordinate systemLOG-LOG coordinate system

Seems more naturalSeems more natural power function transformed to linear functionpower function transformed to linear function

Additional degree of freedomAdditional degree of freedom But: numerical and algorithmic problemsBut: numerical and algorithmic problems

Page 19: An Interactive Perception Based Model for Characterization of Display Devices 1 Institute of Computer Graphics and Algorithms Vienna University of Technology,

Attila Neumann Computergraphik @ TU Wien

ResultsResults CRT monitorCRT monitor

R,G,B results R,G,B results byby our method our method

Compared to Compared to simple power simple power functionfunction

Perceivable Perceivable deviationdeviation

Derivative can deviate upto 0.4-0.6 !

Page 20: An Interactive Perception Based Model for Characterization of Display Devices 1 Institute of Computer Graphics and Algorithms Vienna University of Technology,

Attila Neumann Computergraphik @ TU Wien

ResultsResults Compared to Compared to

spectro-spectro-photometer photometer measurementsmeasurements

Absolute/relative Absolute/relative data conversiondata conversion

Accuracy Accuracy acceptableacceptable

Mutual Mutual verificationverification

Page 21: An Interactive Perception Based Model for Characterization of Display Devices 1 Institute of Computer Graphics and Algorithms Vienna University of Technology,

Attila Neumann Computergraphik @ TU Wien

Conclusion, future workConclusion, future work+ + Human based TRC measurementHuman based TRC measurement

Cheap solutionCheap solution New implicit approachNew implicit approach

+ + Complements existing methodsComplements existing methods Traditional gamma appletTraditional gamma applet Masking model [Tamura 2003]Masking model [Tamura 2003]

? ? Missing absolute luminance valuesMissing absolute luminance values By channel, cross effectsBy channel, cross effects

contrast value by human observationcontrast value by human observation

? ? Preferring LOG-LOG type functionsPreferring LOG-LOG type functions Instead of spline-like (LIN-LIN) functionsInstead of spline-like (LIN-LIN) functions

? ? Combining with other methods (LIN-LIN, etc)Combining with other methods (LIN-LIN, etc)

Page 22: An Interactive Perception Based Model for Characterization of Display Devices 1 Institute of Computer Graphics and Algorithms Vienna University of Technology,

Attila Neumann Computergraphik @ TU Wien

AcknowledgementsAcknowledgements Supported bySupported by

European Union: RealReflect ProjectEuropean Union: RealReflect Project IST-2001-34744 IST-2001-34744 „„Realtime Visualization of Complex Behaviour Realtime Visualization of Complex Behaviour

in Virtual Prototyping“in Virtual Prototyping“ Spanish GovernmentSpanish Government

TIC2001-2416-C03-01TIC2001-2416-C03-01

Helped with implementationHelped with implementation Benjamin Roch (TU Vienna, Austria)Benjamin Roch (TU Vienna, Austria) Wolfgang Deix (TU Vienna, Austria)Wolfgang Deix (TU Vienna, Austria)

Page 23: An Interactive Perception Based Model for Characterization of Display Devices 1 Institute of Computer Graphics and Algorithms Vienna University of Technology,

Attila Neumann Computergraphik @ TU Wien

Thank you Thank you for your attentionfor your attention

[email protected]