Color Models - Computer Science at UBC.ppt

colorininformationdisplay maureenstonestonesoupconsulting effectivecolor illustrators cartographersartists designersafewscientificprinciples whatiscolor physicalworld visualsystem mentalmodels lights surfaces objects eye opticnerve visualcortex red green brownbright light dark vivid colorful dullwarm cool bold blah attractive ugly pleasant jarring perceptionandcognition colormodels physicalworld visualsystem mentalmodels physicalworld spectraldistributionvisiblelightpowervs wavelengthanysourcedirecttransmittedreflectedrefracted fromafieldguidetodigitalcolor a k peters 2003 coneresponse encodespectraasthreevalueslong mediumandshort lms trichromacy onlylmsis seen differentspectracan lookthesame sortoflikeadigitalcamera fromafieldguidetodigitalcolor a k peters 2003 effectsofretinalencoding allspectrathatstimulatethesameconeresponseareindistinguishable metamericmatch colormeasurement ciestandardobservercietristimulusvalues xyz allspectrathatstimulatethesametristimulus xyz responseareindistinguishable fromafieldguidetodigitalcolor a k peters 2003 projectx y zonaplanetoseparatecolorfulnessfrombrightnessx x x y z y y x y z z z x y z 1 x y z chromaticitydiagram xyz xyy rgbchromaticity r g barepoints varyinglightness sumoftwocolorsliesonlinegamutisatrianglewhite gray blacknearcentersaturatedcolorsonedges displaygamuts fromafieldguidetodigitalcolor a k peters 2003 projectorgamuts fromafieldguidetodigitalcolor a k peters 2003 pixelstointensity lineari kp i intensity p pixelvalue kisascalar bestforcomputationnon lineari kp1 perceptuallymoreuniformmoreefficienttoencodeaspixelsbestforencodinganddisplay pixeltointensityvariation intensitytransferfunction itf or gamma colormodels physicalworld visualsystem mentalmodels trichromacymetamerismcolormatchingcolormeasurement opponentcolor definitionachromaticaxisr gandy baxisseparatelightnessfromchromachannelsfirstlevelencodinglinearcombinationoflmsbeforeopticnervebasisforperceptiondefines colorblindness vischeck simulatescolorvisiondeficiencieswebserviceorphotoshopplug inrobertdoughertyandalexw deuteranope protanope tritanope 2dcolorspace similarcolors protanope deuteranope luminance genesinvischeck smartmoney colormodels physicalworld visualsystem mentalmodels separatelightness chromacolorblindnessimageencoding perceptualcolorspaces lightness hue colorfulness uniqueblackandwhiteuniformdifferencesperception design munsellatlas courtesygretag macbeth cielabandcieluv lightness l plustwocoloraxis a b non linearfunctionofciexyzdefinedforcomputingcolordifferences reflective cielab cieluv fromprinciplesofdigitalimagesynthesisbyandrewglassner sf morgankaufmannpublishers fig 2 4 2 5 page63 64 1995bymorgankaufmannpublishers usedwithpermission psuedo perceptualmodels hls hsv hsbnotperceptualmodelssimplerenotationofrgbviewalonggrayaxisseeahuehexagonlorvisgrayscalepixelvaluecannotpredictperceivedlightness lvs luminance l luminancevalues l values lfromhlsallthesame cornersofthergbcolorcube lightnessscales lightness brightness luminance andl lightnessisrelative brightnessabsoluteabsoluteintensityislightpowerluminanceisperceivedintensityluminancevarieswithwavelengthvariationdefinedbyluminousefficiencyfunctionequivalenttocieyl isperceptuallyuniformlightness luminance intensity intensityintegralofspectraldistribution power luminanceintensitymodulatedbywavelengthsensitivityintegralofspectrum luminousefficiencyfunction greenandbluelightsofequalintensityhavedifferentluminancevalues luminancefromrgb l rlr glg blblr lg lbmaximumluminanceofrgbprimariesdifferentfordifferentdisplaysaffectedbybrightness contrastcontrolsr g brelativeintensityvalues linear dependson gammacurve notpixelvalues notafixedequation colormodels physicalworld visualsystem mentalmodels colordifferences intuitive colorspacescolorscales colorappearance imagecourtesyofjohnmcann imagecourtesyofjohnmcann colorappearance morethanasinglecoloradjacentcolors background viewingenvironment surround appearanceeffectsadaptationsimultaneouscontrastspatialeffectscolorincontext colorappearancemodelsmarkfairchild surround background stimulus simultaneouscontrast addopponentcolordarkaddslightredaddsgreenblueaddsyellow thesesampleswillhavebothlight darkandhuecontrast affectslightnessscale bezoldeffect crispening perceiveddifferencedependsonbackground fromfairchild colorappearancemodels spreading spatialfrequencythepaintchipproblemsmalltext lines glyphsimagecolorsadjacentcolorsblend redrawnfromfoundationsofvision brianwandell stanforduniversity colormodels physicalworld visualsystem mentalmodels adaptationcontrasteffectsimageappearancecomplexmatching effectivecolor whatmakescoloreffective goodideasexecutedwithsuperbcraft e r tufteeffectivecolorneedsacontextimmediatevs studiedanyonevs specialistcriticalvs contextualcultureandexpectationstimeandmoney whyshouldyoucare poorlydesignedcolorisconfusingcreatesvisualcluttermisdirectsattentionpoordesigndevaluestheinformationvisualsophisticationevolutionofdocumentandwebdesign attractivethingsworkbetter donnorman informationdisplay graphicalpresentationofinformationcharts graphs diagrams maps illustrationsoriginallyhand crafted staticnowcomputer generated dynamiccolorisakeycomponentcolorlabelsandgroupscolorscales colormaps multi variatecolorencodingcolorshadingandtexturesandmore www nps gov color includesgray mapscourtesyofthenationalparkservice www nps gov colordesign goalshighlight emphasizecreateregions groupillustratedepth shapeevokenaturedecorate makebeautifulcolorharmony successfulcolorcombinations whetherthesepleasetheeyebyusinganalogouscolors orexcitetheeyewithcontrasts principlesofcolordesign bywuciuswong colordesignterminology hue colorwheel red yellow blue primary orange green purple secondary oppositescomplement contrast adjacentareanalogousmanydifferentcolorwheels sforexampleschroma saturation intensityorpuritydistancefromgrayvalue lightness darktolightappliestoallcolors notjustgray tintsandtones toneorshadehue blackdecreasesaturationdecreaselightnesstinthue whitedecreasesaturationincreaselightness gradations colordesignprinciples controlvalue lightness ensurelegibilityavoidunwantedemphasisusealimitedhuepalettecontrolcolor popout definecolorgroupingavoidclutterfromtoomanycompetingcolorsuseneutralbackgroundscontrolimpactofcolorminimizesimultaneouscontrast envisioninginformation avoidingcatastrophebecomesthefirstprincipleinbringingcolortoinformation aboveall donoharm e r tufte fundamentaluses tolabeltomeasuretorepresentortoimitaterealitytoenlivenordecorate tolabel identifybycolor informationvisualizationcolinware productcategories createdbytableau visualanalysisfordatabasestm grouping highlighting considerationsforlabels howcriticalisthecolorencoding uniquespecificationorisita hint quickresponse ortimeforinspection istherealegend orneeditbememorized contextualissuesarethereestablishedsemantics groupingororderingrelationships surroundingshapesandcolors shapeandstructuralissueshowbigaretheobjects howmanyobjects andcouldtheyoverlap needtheybereadable oronlyvisible controlsandalerts aircraftcockpitdesignquickresponsecriticalinformationandconditionsmemorized5 7uniquecolors easilydistinguishablehighwaysignsquickresponsecriticalbutredundantinformation10 15colors typicalcolordesktopaidtosearchredundantinformationpersonalanddecorativehowmanycolors psychophysicsoflabeling 13579345978274055249379164782541372387659727710386619874367259047362956372836491056763254378795483675456840378465485690 timeproportionaltothenumberofdigits 13579345978274055249379164782541372387659727710386619874367259047362956372836491056763254378795483675456840378465785690 timeproportionaltothenumberof7 s 13579345978274055249379164782541372387659727710386619874367259047362956372836491056763254378795483675456840378465785690 both3 sand7 s popout preattentive popout contrastcreatespop out hueandlightness lightnessonly pop outvs distinguishable pop outtypically 5 6distinctvaluessimultaneouslyupto9undercontrolledconditionsdistinguishable20easilyforreasonablesizedstimulimoreifinacontrolledcontextusuallyneedalegend radiospectrummap 33colors http www cybergeography org atlas us spectrum map pdf distinguishableoninspection tableaucolorexample colorpaletteshowmany algorithmic basiccolors regularandpastel extensible customizable colorappearanceasafunctionofsizeasafunctionofbackgroundrobustandreliablecolornames tableaucolors maximumhueseparation analogous yetdistinct sequential colornames basicnames berlin kay linguisticstudyofnamessimilarnamessimilarevolutionmanydifferentlanguages distinctcolors distinctnames distinct buthardtoname colornamesresearch selectionbynameberk brownston kaufman 1982meier et al 2003imagerecoloringsaito et al labelsinvisualizationd zmura cowan popoutconditions healey booth automaticselection webexperimentmoroney et al 2003worldcolorsurvey kay cook http www icsi berkeley edu wcs tomeasure datatocolor typesofdatavaluesnominal ordinal numericqualitative sequential divergingtypesofcolorscaleshuescalenominal labels cyclic learnedorder lightnessorsaturationscalesorderedscaleslightnessbestforhighfrequencymore darker ormoresaturated mostaccurateifquantized colorscales longhistoryingraphicsandvisualizationware robertsonet allevkowitzet alrheinganspravdacolorrogowitzandtreinishibmresearchcartographycynthiabrewercolorbrewer differentscales rogowitz treinish hownottoliewithvisualization densitymap lightnessscale lightnessscalewithhueandchromavariation huescalewithlightnessvariation phasediagrams huescale theopticalsingularitiesofbianisotropiccrystals bym v berry singularitiesoccurwhereallcolorsmeet phasesofthetides figure1 9 cotidalchart tidephasesrelativetogreenwichareplottedforalltheworld soceans phaseprogressesfromredtoorangetoyellowtogreentobluetopurple thelinesconvergeonanphidromicpoints singularitiesontheearth ssurfacewherethereisnodefinedtide winfree 1987 1195 p 17 brewerscales nominalscalesdistincthues butsimilaremphasissequentialscalevaryinlightnessandsaturationvaryslightlyinhuedivergingscalecomplementarysequentialscalesneutralat zero thematicmaps uscensusmap mappingcensus2000 thegeographyofu s diversity brewer scategories cynthiabrewer pennsylvaniastateuniversity colorbrewer www colorbrewer org tableaucolorexample colorscalesforencodingdatadisplayedaschartsandgraphsquantizedorcontinuousissuescolorrampsbasedonbrewer sprinciplesnotsinglehue chromavaryinginlightnesscreatearampofthe samecolor legibledifferentthandistinguishablecenter balanceofdivergingramps heatmap defaultramp skeweddata slightlynegative fullrange skeweddata stepped skeweddata threshold skeweddata colorandshading shapeisdefinedbylightness shading color hue saturation labels imagecourtesyofsiemens ctimage definesshape petcolorhighlightstumor coloroverlay temperature 3dlineintegralconvolutiontovisualize3dflow lic colorvariesfromredtoyellowwithincreasingtemperature http www users cs umn edu interran 3dflow html victoriainterranteandchestergrosch u minnesota multivariatecolorsequences multi dimensionalscatterplot variable1 2 x yvariable3 4 5 r g b usingcolordimensionstodisplaydatadimensionsbeattyandware dopeopleinterpretcolorblendsassumsofvariables colorweaves 6variables 6hues whichvaryinbrightness additivemixture blend spatialtexture weave weavingversusblending apgv06andsiggraphposter halehhagh shenas victoriainterrante christopherhealeyandsungheekim brewersystem http www colorbrewer org brewerexamples torepresentorimitatereality illustrativecolor gray sanatomyofthehumanbody mapofpointreyes www nps gov themeview original courtesyofpacificnorthwestnationallaboratories themescape commercial courtesyofcartia toenlivenordecorate visualizationofisoelectrondensitysurfacesaroundmoleculesmarclevoy 1988 whichhasmoreinformation whichwouldyouratherlookat moretufteprinciples limittheuseofbrightcolorssmallbrightareas dullbackgroundsusethecolorsfoundinnaturefamiliar naturallyharmonioususegrayedcolorsforbackgroundsquiet versatilecreatecolorunityrepeat mingle interweave controllingvalue getitrightinblack white valueperceivedlightness darknesscontrollingvalueprimaryrulefordesignvaluedefinesshapenoedgewithoutlightnessdifferencenoshadingwithoutlightnessvariationvaluedifference contrast defineslegibilitycontrolsattentioncreateslayering controlslegibility colorusage arc nasa gov legibility dropshadowsdropshadow dropshadowaddsedge readability ifyoucan tusecolorwisely itisbesttoavoiditentirelyaboveall donoharm ifyoucan tusecolorwisely itisbesttoavoiditentirelyaboveall donoharm wh