Visual color matching under various viewing...

Visual Color Matching underVarious Viewing Conditions

Hitoshi Komatsubara,1* Shinji Kobayashi,1Nobuyuki Nasuno,1 Yasushi Nakajima,2Shuichi Kumada2

1 Japan Color Research Institute, 4-6-23 Ueno Iwatsuki-shi, Saitama, Japan

2 Canon Inc., 3-30-2 Shimomaruko Otaku, Tokyo, Japan

Received 2 March 2001; accepted 6 February 2002

Abstract: In this article, we provide colorimetry data forwhich it was judged that the colors between different mediamatched under various viewing conditions. Painted colorpatches, a monitor, and printed color patches were used inthe color matching experiments, in which we compared theappearances of the painted color patch and the monitor, orthe monitor and the printed color patch, using the method ofconstant stimuli. The nine types of viewing conditions weused could be envisaged to occur when comparing differentdevice outputs indoors. The experimental data obtainedwere compared with corresponding colors predicted withthe use of five types of color appearance model, includingcolor appearance formulae. We found that when the view-ing conditions were the same for the different media, therewas good agreement between the experimental data and theCIECAT94 model. And by adjusting the brightness induc-tion and the chromatic induction factors, it was possible toimprove conformity for the lightness and the chromaticity.Moreover, it was possible to improve the white point shift,which cannot be adjusted with the use of optimized param-eters by introducing incomplete adaptation. By optimizingthe parameters and introducing incomplete adaptation, it ispossible to make the mean color difference �E*ab betweenthe corresponding color and the color matching point lessthan 10 CIELAB units for all of the viewing conditions.© 2002 Wiley Periodicals, Inc. Col Res Appl, 27, 399–420, 2002; Pub-

lished online in Wiley InterScience (www.interscience.wiley.com). DOI

10.1002/col.10091

Key words: cross-media; color appearance; color matchingexperiment; color appearance model; parameter

INTRODUCTION

Metamerism occurs as a result of the differences in thecoloring materials and the color production methods, withthe surface colors reproduced by paints or dyes and photo-graphs or printer outputs. In the same way, metamerismoccurs between surface colors and monitor outputs. More-over, monitors make use of the luminescence of phosphors,and so produce a different color mode to that of surfacecolors. It is known that whether or not the colors producedby such different media match one another depends on theviewing conditions. Braun and Fairchild1 have reported thatwhen the viewing conditions are the same for the differentmedia, the appearances of the colors on the different mediacan be matched by colorimetric color matching the color-imetry values. Luo et al.2–4 have reported data obtained byevaluating the color appearances for surface and luminouscolor modes under a variety of viewing conditions with theuse of a magnitude estimation technique. Mori et al.5 havereported observation data for the corresponding colors un-der various chromatic adaptations. However, these reportsinvolved different evaluation techniques and viewingconditions, so whether or not the data are compatible witheach other is a problem. The guidelines6 for coordinatedresearch on evaluation of color appearance between reflec-tion print and self-luminous displays were thus publishedwith CIETC1-27, and it was proposed that observation databe collected. Three evaluation methods—successive haplo-scopic viewing configuration, successive binocular viewingarrangement, and magnitude estimation—were proposed.Moreover, Braun et al.7 have carried out comparative stud-

* Correspondence to: Hitoshi Komatsubara, Japan Color Research In-stitute, 4-6-23 Ueno Iwatsuki-shi, Saitama, Japan ([email protected])© 2002 Wiley Periodicals, Inc.

Volume 27, Number 6, December 2002 399

ies of a number of cross-media image-viewing techniques.In our current research, a painted color patch and a monitor,or a monitor and a printed color patch, were used so as tocorrespond to simultaneous binocular viewing, and we eval-uated the color appearances using the constant method.However, because the color chart and the monitor, or themonitor and the printed color patch, could not both fit intothe visual field at the same time, in actual practice, the setupeffectively corresponded to a successive binocular viewingarrangment. There are separate ISO stipulations from theInternational Organization for Standardization (ISO) for theviewing conditions when carrying out visual comparisonwith color charts8 and with photographs.9 However, thereare no standard viewing conditions when directly compar-ing the colors produced by different media. In our currentresearch, we surveyed the trends in ISO deliberations and inJapanese industry, and carried out comparisons under oneset of standard viewing conditions and eight sets of practicalviewing conditions. We carried out the color appearancecomparisons using only color patches, and estimated thecolor matching points and ranges for which we thought thatthe colors matched between the painted color patch and the

monitor, or the monitor and the printed color patch, usingprobit analysis, which is a constant method analytic tech-nique. The color matching points were compared with cor-responding colors predicted using five types of chromaticadaptation formulae and color appearance models.

METHODS

Canon Color-Matching Data

Viewing Conditions. With the CIE colorimetry system, thefollowing are recommended as standard viewing condi-tions10:

Illuminant: Standard illuminant D65Illuminance: �1,000 lxBackground luminance: �64 cd/m2

Background: Gray (L10* � 50)

Sample size: At least 4°

These conditions assume evaluation of surface colors in abright room. However, it is assumed that, in general, amonitor is viewed in a dark room as with the viewing

FIG. 1. Layout of experiment.

TABLE I. Viewing condition investigation.

Exp. no.Print whitepoint (K)

CRTwhite

point (K)Background(print/CRT)

Surround(print/CRT)

Luminance(cd/m2)

(print/CRT)Monitorshade

S 6,500 6,500 N5Gray/N5Gray Dark/Dark 96/110 N1 6,500 6,500 N5Gray/N5Gray Light/Light 157/90 N2 6,500 9,300 N5Gray/N5Gray Light/Light 157/90 N3 6,500 5,000 N5Gray/N5Gray Light/Light 157/90 N4 4,200(F6) 6,500 N5Gray/N5Gray Light/Light 157/90 N5 4,200(F6) 9,300 N5Gray/N5Gray Light/Light 157/90 N6 5,000(F10) 6,500 N5Gray/N5Gray Light/Light 157/90 N7 6,500 6,500 N5Gray/N5Gray Light/Light 76/90 N8 6,500 6,500 N5Gray/N5Gray Light/Light 157/90 Y

400 COLOR research and application

conditions for a TV monitor. Moreover, the maximum lu-minance for a monitor depends on the luminance of theluminescent red, green, and blue phosphors (RGB). Whencarrying out comparisons between different media such as acolor patch and a monitor, it is thus necessary to set con-ditions that can be realized with both of the media. There arelimitations on the luminance range that can be reproducedby a monitor, so viewing conditions that can be reproducedwith a monitor but also come as close as possible to satis-

fying the International Commission on Illumination (CIE)colorimetry system viewing conditions were our standardviewing conditions. Moreover, we presumed that lightsources having a whole variety of characteristics are used inindustry, so conditions that are close to the actual environ-ments were taken as practical viewing conditions. The stan-dard viewing condition (S) and the practical viewing con-ditions (sets 1–8) are shown in Table I.

Experimental Apparatus. The apparatus used in the ex-periments and its layout are shown in Figs. 1 and 2. Asample stand with a center height of 275 mm was installedin a light booth equipped with a D65 simulator placed on atable (which was 75 cm above the floor) for the standardcondition and directly on a table having a gray backgroundof luminance factor 0.2 for practical conditions. The lightbooth with a gray background of luminance factor 0.2 wasused only in the comparisons carried out under the standardviewing conditions. With the practical viewing conditions,we used the illuminant of color patch on the sample standwith the ambient lighting in the laboratory. A cathode raytube monitor (CRT) was also placed in the light booth or onthe table, with the same center height as that of the center ofthe sample stand. With 35 � 35 mm color patches on a

FIG. 2. Stimulus configuration.

TABLE II. Colorimetric data for the painted color patches.

No. Color X Y Z L* a* b*

2 5R5/3 20.77 20.80 16.57 52.73 10.45 3.863 5R5/10 26.20 19.90 10.69 51.73 39.45 17.704 5Y5/3 18.30 20.80 10.79 52.73 �2.23 19.135 5G5/3 16.08 21.48 16.53 53.47 �17.78 5.206 5G5/6 13.84 21.32 14.58 53.29 �30.81 9.617 5B5/3 16.76 21.29 23.40 53.26 �13.00 �9.238 5B5/8 15.02 22.06 33.90 54.09 �26.76 �24.729 5PB5/4 18.11 20.90 26.29 52.84 �3.72 �15.05

10 5PB5/7 17.63 20.51 33.16 52.41 �4.51 �26.5411 5P5/4 19.97 20.55 24.08 52.45 7.67 �11.8512 7.5P5/10 24.56 19.84 30.11 51.66 32.71 �23.2713 5RP5/4 21.09 20.42 19.07 52.31 13.86 �2.3914 5RP5/9 26.49 20.51 19.74 52.41 37.71 �3.6016 5R6/6 32.07 28.99 19.74 60.77 23.59 10.8117 5YR6/4 29.05 29.38 17.24 61.11 10.64 16.7718 5YR6/8 33.36 30.66 11.17 62.22 22.03 34.3219 5Y6/5 26.58 29.73 11.36 61.42 �0.70 32.3620 5GY6/5 23.11 29.66 12.52 61.36 �15.62 28.9521 10GY6/5 21.80 30.11 16.66 61.75 �23.44 19.1822 10GY6/7 20.32 30.18 13.58 61.81 �30.89 26.8523 5G6/6 20.61 30.72 21.03 62.27 �31.46 10.8224 5BG6/6 20.90 30.92 29.47 62.44 �30.74 �3.6925 5B6/5 23.63 31.11 37.56 62.60 �18.61 �15.1026 5PB6/5 26.52 30.43 39.68 62.03 �3.59 �18.8727 5P6/6 29.66 29.38 37.14 61.11 13.03 �17.1128 5RP6/6 32.65 29.86 27.74 61.53 22.44 �2.4730 5R7/4 42.92 42.47 32.94 71.20 14.83 6.1731 5YR7/4 41.80 42.70 26.33 71.35 10.73 16.8132 5Y7/4 37.85 42.47 20.51 71.20 �1.21 27.2233 5Y7/7 38.14 42.38 12.23 71.13 0.03 46.6034 5GY7/4 34.58 42.47 22.38 71.20 �12.34 23.6035 5GY7/7 33.07 43.24 14.35 71.72 �19.97 41.9536 5G7/5 30.63 42.12 30.63 70.95 �25.70 9.2137 5BG7/4 32.23 42.54 38.75 71.24 �20.94 �1.7838 5B7/4 34.83 43.40 47.39 71.83 �14.17 �11.3239 5PB7/4 37.85 43.12 49.83 71.63 �3.09 �14.4040 5P7/4 40.48 42.18 46.07 71.00 8.14 �11.23


135 � 135 mm gray background of luminance factor 0.2,with a 10mm white border placed on the sample stand andpresented on the CRT, we made comparisons for eachcondition. The observer alternately viewed the color patchon the sample stand and that on the CRT from a distance of1 m, and judged whether or not the colors matched, with thedistance to the center of the sample stand and that of the

CRT being 60 cm. The sizes of the color patches corre-sponded to an angle of view of about 2°. The white borderswere set as the reference white of the sample stand and theCRT. With a Canon CLC700 color laser printer, we usedpainted color patches and printed color patches presented onthe sample stand. The colorimetric data of the painted colorpatches by Minolta spectrophotometer CM2002 are shownin Table II. These color patches could be reproduced usingthe CRT and the printer.

The color patches presented on the CRT were displayed ona Barco Reference Calibrater CCID120T driven by a Cam-bridge Research System visual stimulus generator (VSG).However, the color matching points for the color patches andthe CRT color patches vary according to the viewing condi-tions, so we carried out preliminary experiments using theadjustment method in order to obtain assumed color matchingpoints. The color patches presented on the CRT were producedwith color difference in six directions (�hue, �hue, �lighte-ness, �lighteness, �chroma, and �chroma) from the prede-termined color matching point. And we used an XYZ trans-formation matrix obtained from the CRT input signal/luminance characteristic in the color prediction for the CRT

FIG. 3. Frequency probability.

TABLE III. Color matching points between the painted color patch and the CRT color patches.

No. Color

Color matching point Acceptable range

L* a* b* �H*ab �L*ab �C*ab

2 5R5/3 50.20 12.51 2.15 1.0 0.0 0.03 5R5/10 49.77 42.26 15.67 1.5 0.5 1.54 5Y5/3 50.51 �0.95 17.87 0.0 0.7 4.05 5G5/3 51.75 �14.81 2.37 1.2 1.4 2.06 5G5/6 52.74 �28.16 7.03 1.7 1.2 3.17 5B5/3 52.05 �9.72 �10.96 1.1 1.7 1.98 5B5/8 52.32 �23.49 �28.10 3.3 1.8 2.89 5PB5/4 51.40 �1.84 �18.22 0.9 1.4 1.9

10 5PB5/7 50.70 �1.18 �31.09 1.2 1.5 2.711 5P5/4 51.35 8.94 �14.82 0.3 0.3 1.812 7.5P5/10 51.57 32.96 �27.14 1.9 2.0 5.813 5RP5/4 51.54 15.24 �4.54 1.7 0.8 2.014 5RP5/9 51.22 38.68 �6.71 0.9 1.9 4.016 5R6/6 58.81 24.76 8.86 1.5 1.8 3.817 5YR6/4 57.54 13.48 12.63 0.0 1.7 2.918 5YR6/8 59.64 24.74 33.81 0.3 1.0 6.619 5Y6/5 59.45 0.28 33.60 0.0 0.5 7.220 5GY6/5 60.84 �13.86 24.28 1.9 1.3 2.821 10GY6/5 59.24 �21.71 15.27 0.9 2.0 3.922 10GY6/7 60.66 �28.84 23.92 2.1 1.8 4.623 5G6/6 60.15 �27.64 6.62 1.8 2.0 4.624 5BG6/6 59.97 �26.70 �5.44 2.1 2.6 4.525 5B6/5 59.39 �14.20 �16.65 2.4 2.6 3.126 5PB6/5 60.35 �1.34 �22.05 1.6 2.6 3.327 5P6/6 57.90 15.98 �21.43 0.8 1.1 1.628 5RP6/6 60.63 22.82 �5.52 2.3 2.5 2.930 5R7/4 68.58 15.75 2.18 1.7 1.4 1.131 5YR7/4 67.10 12.27 15.64 0.8 1.5 1.332 5Y7/4 68.76 �0.53 24.57 0.7 2.1 2.333 5Y7/7 67.87 �0.67 43.20 1.0 1.5 4.834 5GY7/4 70.62 �11.51 18.95 1.9 2.6 3.335 5GY7/7 69.66 �17.11 33.32 2.6 0.7 2.136 5G7/5 67.31 �24.86 6.50 2.0 2.9 3.837 5BG7/4 68.64 �19.08 �4.22 3.1 3.5 3.138 5B7/4 68.19 �11.32 �13.18 2.9 3.2 1.939 5PB7/4 67.69 �1.59 �15.91 1.0 2.4 1.540 5P7/4 69.27 10.50 �15.37 0.3 0.0 1.1


color patches. As with the CRT color patches, the printed colorpatches were produced by determining assumed color match-ing points between the printed color patches and the CRT colorpatches through results of preliminary experiments. The

printed color patches were also produced with color differencein six directions (�hue, �hue, �lightness, �lightness,�chroma, and �chroma) from the predetermined color match-ing points.

FIG. 4. Color matching points and acceptable threshold. The circles indicate a* and b* chromaticity of painted colorpatches; solid lines indicate tolerance vectors of CRT color matching point; dashed lines indicate tolerance vectors of printercolor matching point (upper: L* � 50; middle: L* � 60; lower: L* � 70).

TABLE IV. Color matching points between the CRT color patch and the printed color patches.

No. Color

Color matching point Acceptable range

L* a* b* �H*ab �L*ab �C*ab

2 5R5/3 53.41 11.92 2.39 0.0 1.1 0.13 5R5/10 53.93 40.75 16.64 1.5 2.9 2.54 5Y5/3 54.97 �0.79 19.90 0.1 0.2 0.75 5G5/3 55.54 �16.36 3.10 1.1 2.4 1.56 5G5/6 58.21 �27.79 10.02 0.6 2.1 0.97 5B5/3 55.26 �8.45 �10.07 1.7 1.0 0.98 5B5/8 56.52 �23.73 �24.82 0.3 1.7 1.59 5PB5/4 55.52 �2.59 �17.00 0.1 1.3 0.2

10 5PB5/7 54.55 �4.48 �28.92 1.9 2.6 3.111 5P5/4 55.12 9.65 �13.14 0.5 1.9 1.912 7.5P5/10 54.86 32.14 �23.16 1.1 1.3 1.413 5RP5/4 55.90 16.62 �2.91 0.3 1.5 0.714 5RP5/9 57.14 38.37 �6.36 3.1 4.5 5.616 5R6/6 62.51 25.79 11.92 3.5 4.0 3.417 5YR6/4 62.20 16.43 17.44 1.8 4.4 3.018 5YR6/8 63.01 29.34 39.37 4.0 3.1 5.819 5Y6/5 63.97 1.88 39.35 1.7 3.7 4.620 5GY6/5 66.70 �11.17 28.71 2.5 3.9 5.121 10GY6/5 64.05 �23.84 19.89 3.6 4.4 5.922 10GY6/7 66.34 �32.10 31.59 3.3 3.0 6.223 5G6/6 62.42 �28.97 8.28 1.1 1.9 1.524 5BG6/6 64.83 �26.81 �2.90 3.6 3.7 4.325 5B6/5 64.54 �16.03 �15.08 2.0 2.9 1.926 5PB6/5 62.38 �2.98 �19.78 1.7 1.7 1.827 5P6/6 59.90 15.75 �18.98 1.1 2.1 1.328 5RP6/6 65.11 24.37 �3.71 3.8 3.4 3.730 5R7/4 71.54 18.46 4.98 1.7 3.2 3.231 5YR7/4 71.55 14.65 18.36 3.1 5.2 3.432 5Y7/4 73.41 1.29 30.28 1.9 5.5 5.933 5Y7/7 72.97 2.14 52.86 2.1 4.1 9.734 5GY7/4 75.19 �8.59 21.93 2.5 4.0 4.935 5GY7/7 75.68 �14.50 38.63 2.9 4.8 6.836 5G7/5 73.64 �25.05 9.88 2.7 5.4 4.837 5BG7/4 74.13 �18.32 �1.41 3.3 3.8 4.038 5B7/4 74.10 �12.89 �12.08 3.0 3.0 3.039 5PB7/4 70.99 �3.25 �13.25 1.5 4.0 1.940 5P7/4 73.96 10.69 �12.20 1.5 3.0 1.8


The CIELAB values for the painted, the CRT, and the theprinted color patches were measured under each of the setsof viewing conditions with a Topcon BM-7 luminancecolorimeter.

Psychological Evaluation Method. When comparing asurface color with the CRT color produced by inputting thissurface color with an input device such as scanner or digitalcamera, we perceived a color difference even under thestandard viewing conditions. We thought that it should bepossible to achieve colorimetric color matching under thestandard viewing conditions. However, it is not possible toreduce the color difference to zero, due to factors such as theprofile accuracies of the input device and the CRT. There isthus a problem as to how large the color difference betweenmedia may be before it becomes unacceptable. In our cur-

rent research, color patches were thus compared with oneanother visually, and the color matching point and accept-able range were determined. The following example illus-trates the experimental procedure comparing painted colorpatches with CRT color patches.

Observers view the gray background in the light booth inorder to adapt to the illuminant. One of the color patchesshown in Table II is selected at random and placed on thesample stand as a reference sample. Observers first view thereference sample, and then the color patches presented atrandom, one after another on the CRT, with each eithercorresponding to the predetermined assumed color match-ing point or else having hue, lightness, and chroma thatdiffer from the assumed color matching point. Observerssuccessively compare the painted color patch with the CRTcolor patch by shifting their line of sight, and evaluating thecolor difference between the the reference color and theCRT color patch in accordance with the following judgmentcriteria:

1. Color difference is acceptable.2. Cannot say whether color difference is acceptable or

unacceptable.3. Color difference is unacceptable.

After completing their evaluation for a color patch, ob-servers input their judgment results into the VSG usingnumber keys; then, the next color patch is presented. Oncejudgment has been completed for all the prepared CRTcolor patches, the reference color patch on the sample standis changed.

Under the standard viewing condition, each observercompared the reference painted color patch with CRT colorpatches, and the reference CRT color patch having similarcolor matching points between a painted color patch and aCRT color patch with printed color patches. Under thepractical viewing conditions, each observer only comparedthe reference CRT color patch with printed color patches by

FIG. 5. Lightness difference of matching points frompainted color patches and acceptable threshold. The brokenline indicates mean value each lightness level (left: L* � 60;middle: L* � 70; right: L* � 80).

TABLE V. Average color difference of color matching point from painted color patch, and averageacceptable ranges.

Value

Average color difference

CRT color patch Printed color patch

�H*ab �L*ab �C*ab �E*ab �H*ab �L*ab �C*ab �E*ab

5 2.5 1.4 2.2 3.9 1.5 2.7 1.7 3.86 2.3 2.1 2.8 4.6 1.8 2.2 3.4 4.87 2.0 2.8 2.7 5.0 1.8 2.2 2.8 4.3Average 2.2 2.1 2.6 4.5 1.7 2.4 2.6 4.3

value

Average acceptable range

CRT color patch printed color patch

�H*ab �L*ab �C*ab �E*ab �H*ab �L*ab �C*ab �E*ab

5 1.3 1.2 2.6 — 1.0 1.9 1.6 —6 1.4 1.8 4.0 — 2.6 3.2 3.7 —7 1.6 2.0 2.4 — 2.4 4.2 4.5 —Average 1.4 1.7 3.0 — 2.0 3.1 3.3 —


the same experimental procedure as that used for comparingpainted color patches with CRT color patches.

Each observer carried out three evaluations for the colorpatches in Table I. The 4 observers for the standard condi-tion and 7 observers for other conditions all had normalcolor perception.

RESULTS

Evaluation Results under Standard ViewingConditions

Figure 3 shows a graph of the average probability ofobservers for color patch No. 8 under the standard viewingconditions against the color difference from the assumedcolor matching point. This was calculated by taking theprobability for judgment criterion 1 to be 1, that for criterion2 to be 0.5, and that for criterion 3 to be 0, thus correspond-ing to the probability of acceptance. Because the distribu-tion of the probability is approximated by an ogive, the

color corresponding to a probability of 50% can be taken asbeing the acceptable threshold for the color patch in ques-tion. In actual practice, the threshold can be caluculated byusing the probit analysis,11 which is a method of predictingthe threshold for method of constant stimuli. The center ofFig. 3 is the same as the assumed color matching point, soit is not necessarily the case that the probability distributionreaches its maximum for this color. In some cases, theresults may lean either to the positive or the negative side.In such cases, the threshold on the positive or negative sidewas estimated after the assumed color matching point wasshifted to the color for which the probability was estimatedas maximum. The results of estimating the threshold be-tween the reference color patch and the CRT color patchesare shown in Table III. The color matching point in Table IIIindicates the midpoint of the positive- and negative-sideacceptable threshold. This is because (as shown in Fig. 3)the probability distribution curves on the positive and neg-ative sides have gently sloping figures, so the midpoint was

TABLE VI. Color matching points and acceptable ranges between the printed color patch and the CRT colorpatch for cases 1 and 2.

ColorNo.

Case 1 Case 2

Printed color patch Color matching point Acceptable range Color matching point Acceptable range

L* a* b* L* a* b* �H*ab �L*ab �C*ab L* a* b* �H*ab �L*ab �C*ab

2 62.39 9.05 1.12 59.36 11.83 1.12 2.01 4.52 2.81 56.07 8.44 8.45 1.00 1.27 1.553 62.17 32.20 11.20 57.49 44.25 16.89 2.05 2.77 4.67 56.43 36.95 22.45 2.33 2.73 3.904 62.98 �2.72 16.63 56.82 �2.30 19.23 1.19 2.85 3.73 59.06 �7.90 31.09 1.17 2.60 3.555 63.13 �12.93 4.02 60.60 �16.74 5.56 1.29 2.33 2.78 58.55 �19.37 12.07 1.94 2.15 1.546 65.45 �20.77 8.06 63.78 �24.88 10.96 0.69 1.63 3.27 60.53 �26.59 17.20 1.60 3.07 2.307 63.28 �6.76 �8.30 59.87 �6.11 �11.14 1.41 2.44 1.90 — — — — — —8 65.00 �14.22 �20.07 60.88 �15.65 �29.15 1.62 3.56 2.06 — — — — — —9 62.34 0.13 �14.66 57.63 2.92 �18.91 1.07 3.01 3.11 — — — — — —

10 62.21 �0.05 �24.37 60.81 4.00 �31.27 1.03 1.58 3.46 57.96 1.70 �22.76 0.59 0.81 0.5811 60.70 28.10 �19.50 58.19 33.85 �24.48 2.62 2.92 4.71 57.07 29.35 �13.10 1.16 2.16 2.6912 62.25 8.11 �11.25 59.28 10.27 �14.39 1.27 2.69 3.13 58.83 8.26 �5.87 1.27 3.32 2.9513 62.78 12.79 �3.55 60.45 18.34 �5.36 1.92 4.65 2.86 58.13 11.29 3.36 1.89 2.99 2.0114 64.17 33.49 �7.65 59.79 41.29 �9.17 2.65 4.41 4.24 60.20 35.78 0.18 2.93 3.10 4.1516 69.01 21.82 9.92 68.65 28.64 13.76 3.23 3.94 4.69 67.84 22.14 20.12 2.77 3.38 3.2417 69.35 9.99 14.33 68.11 12.94 17.64 3.29 4.00 3.43 68.71 7.23 28.99 3.00 3.64 3.3818 69.73 19.62 29.54 67.03 25.80 41.77 4.84 4.51 5.57 63.77 19.54 48.85 2.68 2.73 5.8619 69.35 �0.42 29.54 66.06 0.28 38.63 1.32 3.17 6.27 67.29 �7.02 42.79 1.76 2.66 2.4420 72.75 �12.18 24.08 70.14 �13.22 26.27 2.62 4.30 4.83 71.57 �22.09 39.45 1.25 3.47 4.1921 71.09 �20.01 18.30 69.54 �21.83 20.70 2.76 4.55 5.52 68.85 �31.08 30.62 0.28 2.50 1.4022 72.40 �26.55 24.98 70.79 �29.65 29.53 2.37 4.28 6.53 72.10 �38.69 43.49 2.59 3.59 5.4823 70.28 �22.69 8.84 67.03 �25.82 9.37 1.52 3.61 3.42 66.79 �32.13 20.99 2.09 2.74 2.8924 70.70 �20.70 �2.67 67.76 �22.13 �4.18 3.42 4.66 4.73 68.71 �30.15 8.40 2.95 3.89 3.6625 69.83 �12.65 �12.58 68.00 �14.25 �15.72 2.49 2.97 4.07 67.80 �20.03 �3.71 1.87 2.92 1.9326 68.01 0.08 �17.49 66.14 2.37 �23.26 2.41 4.35 5.00 64.21 �3.39 �12.08 1.48 2.38 3.0127 67.66 10.66 �13.96 65.85 14.65 �19.13 2.34 4.54 4.83 65.16 9.38 �5.89 0.98 1.83 2.6728 70.67 19.55 �9.87 69.63 25.09 �12.88 3.48 4.32 5.03 68.95 20.38 �2.36 1.05 3.51 2.5630 79.09 12.20 7.88 82.09 15.67 9.62 3.05 5.44 3.66 84.24 11.84 19.79 1.94 3.60 2.1131 80.67 8.67 16.90 81.81 11.04 19.17 1.86 5.60 3.06 83.13 4.46 33.08 2.20 3.98 2.5632 81.32 �3.51 26.18 82.43 �4.57 29.03 2.07 4.54 4.46 78.01 �10.27 39.87 1.08 3.46 2.3333 81.70 �2.96 39.37 81.64 �3.48 46.84 1.48 3.66 5.55 80.87 �10.24 53.60 1.10 5.28 4.7434 79.64 �12.16 21.90 79.28 �14.36 24.87 2.74 6.00 5.24 79.38 �21.44 35.95 1.83 4.23 3.1035 80.33 �21.42 39.05 78.70 �24.28 45.71 3.08 4.53 8.06 78.42 �31.61 55.47 2.63 3.28 5.4736 77.92 �21.26 10.19 76.87 �23.86 10.82 3.44 5.61 5.36 76.49 �30.76 22.91 2.56 3.90 3.6737 78.33 �16.07 0.29 79.50 �18.52 �0.64 3.97 5.61 3.67 77.05 �25.01 11.92 2.49 4.10 0.5238 77.13 �11.82 �9.29 76.25 �14.24 �11.43 3.13 4.44 3.86 74.90 �18.92 �0.68 1.18 4.16 0.7439 75.51 �2.90 �11.26 74.72 �2.52 �16.50 1.97 5.25 3.51 74.99 �9.22 �1.53 1.12 3.25 2.1940 75.74 10.45 �9.46 75.35 13.34 �12.63 2.65 5.47 4.28 75.04 9.22 0.62 0.96 4.02 2.63


taken as the color matching point. The acceptable range thusindicates the difference between the positive and negative-side threshold and the color matching point in Table III.

Table IV shows the color matching points between theprinted color patches and the reference CRT color patch,along with the acceptable ranges. However, the colorimetricvalue of the reference CRT color patch used in the compar-ison does not equal the colorimetric value of the colormatching point between the painted color patch and CRTcolor patches in Table II; therefore,the color matching pointwas calculated by performing the following correction,which was done in order to compare the painted/CRT colormatching point with the CRT /printed color matching point.

X� � (XCRT,CMP/XCRT,MEA) X

Y� � (YCRT,CMP/YCRT,MEA) Y

Z� � (ZCRT,CMP/Z]CRT,MEA) Z (1)

Here,

X�, Y�, Z�: Color matching point after correctionX, Y, Z: Color matching point before correctionXCRT,MEA, YCRT,MEA, ZCRT,MEA: Measurement value for the

reference CRT color patch

XCRT,CMP, YCRT,CMP, ZCRT,CMP: Color matching point forthe painted color patch and the CRT color patch inTable II.

Figures 4 and 5 show the relationship between the col-orimetric values of the painted color patches, the colormatching points, and the acceptable ranges. Moreover, Ta-ble V also shows the average color difference between colormatching point and painted color patch, and average accept-able threshold.The hue, lightness, and chroma differencesfor CRT color patches and printed color patches are lessthan 3 CIELAB units, so it appears that colorimetric colorreproduction is more or less achieved. However, with regardto the lightness, there is a tendency for the colors to matchwhen the value is higher for the printed color patch than thatof the CRT color patch, and there is a significant differencebetween the color matching points for the CRT color patchand printed color patch. It is thought that this tendency isdue to the effects of the glossiness of the printed color patchsurface on the colorimetry and the color appearance. Theseeffects are also seen slightly with the chromaticity colormatching points, with the color matching points for theprinted color patches being shifted slightly to the highchroma side. However, unlike the case with the lightness,

TABLE VII. Color matching points and acceptable ranges between the printed color patch and the CRT colorpatch for cases 3 and 8.

ColorNo.

Case 3 Case 8



2 61.57 8.16 2.99 58.24 11.52 �3.63 2.73 3.96 3.68 59.38 15.61 2.34 1.64 2.17 2.463 61.41 31.44 13.36 56.70 43.68 13.58 2.69 4.26 6.13 53.93 47.18 19.06 1.44 3.74 2.904 62.30 �4.00 18.90 57.21 �5.29 19.11 1.57 3.71 5.10 57.92 �3.43 25.33 1.20 2.66 3.935 62.54 �14.27 6.00 57.48 �17.56 �0.08 2.56 4.00 3.62 59.27 �17.86 6.56 0.82 2.95 2.786 64.70 �22.15 10.02 61.16 �28.66 4.05 2.32 4.26 4.00 60.90 �26.82 11.02 1.48 3.03 3.237 62.79 �8.38 �6.24 59.38 �12.17 �19.53 2.42 4.28 3.53 58.38 �8.58 �10.77 1.27 1.49 0.928 64.18 �15.65 �18.66 63.26 �21.87 �41.35 3.18 3.62 6.65 60.04 �16.44 �29.05 1.05 1.64 1.199 61.98 �1.09 �13.20 57.15 �2.52 �27.56 1.15 3.01 4.64 57.52 2.65 �20.70 0.90 2.01 1.82

10 61.92 �1.44 �22.79 56.90 �2.98 �42.79 1.25 2.45 4.24 56.68 3.14 �34.32 1.54 2.40 4.5911 60.60 26.88 �17.81 56.62 32.27 �34.55 3.23 4.40 8.39 56.06 39.87 �27.08 1.00 3.95 3.1112 61.20 7.10 �9.84 58.34 5.58 �20.80 1.76 3.89 5.24 59.43 10.30 �15.60 0.82 2.78 3.4313 61.70 12.05 �2.19 58.90 12.00 �9.37 2.40 3.81 4.47 60.34 17.03 �3.96 2.43 2.32 3.1614 63.65 32.56 �6.04 61.77 41.18 �18.81 4.07 4.19 7.28 61.76 44.79 �9.27 2.93 3.94 4.9116 68.89 20.88 11.57 67.44 26.32 8.63 2.95 4.60 5.42 68.96 30.68 14.58 1.76 3.55 4.4017 69.09 9.11 15.97 69.68 10.19 13.49 2.71 4.20 3.88 67.25 13.47 18.97 1.55 3.65 2.5218 69.09 19.20 30.95 69.22 24.80 38.12 3.54 4.51 6.29 67.79 29.40 45.84 3.21 4.62 7.1519 68.90 �1.24 31.04 68.20 �4.11 36.07 2.09 5.80 8.44 68.55 �0.64 41.04 2.11 3.61 5.7320 72.59 �13.22 25.70 73.04 �18.99 24.51 3.52 6.81 5.86 71.53 �13.63 29.22 0.75 3.94 3.6421 70.44 �21.20 20.00 69.19 �27.94 15.69 2.86 5.27 5.90 68.57 �24.29 22.99 2.03 3.06 4.1022 71.94 �27.21 26.28 69.58 �34.49 25.23 3.77 5.31 8.23 69.95 �33.96 33.45 1.09 3.21 2.9123 69.40 �23.70 10.31 66.78 �29.73 3.78 3.32 3.43 2.27 66.59 �28.52 11.22 2.25 4.11 4.4024 70.31 �22.07 �1.04 67.87 �28.36 �12.63 3.88 5.98 5.67 69.97 �25.30 �3.99 1.67 4.69 2.6625 68.97 �14.13 �10.83 67.22 �18.46 �24.62 3.41 5.57 4.44 66.70 �15.36 �14.07 2.52 3.83 3.7526 67.15 �1.22 �15.77 64.98 �2.87 �33.83 2.17 4.63 4.51 65.24 1.44 �23.88 1.93 4.38 4.5127 67.06 9.21 �11.91 65.86 10.15 �26.80 2.36 5.65 5.54 64.13 14.58 �18.60 2.08 3.77 4.6328 70.91 18.42 �7.87 70.44 20.40 �22.32 3.38 6.75 6.32 70.60 24.62 �12.63 1.64 3.22 3.7730 79.02 11.11 9.87 84.81 13.91 1.48 4.78 6.26 4.26 81.46 17.08 10.48 3.06 5.21 3.4031 80.55 7.57 18.78 85.75 8.17 12.90 3.01 7.22 5.42 86.89 11.63 20.60 1.97 3.20 0.1432 80.70 �4.34 27.83 84.87 �9.54 27.35 2.64 6.48 7.04 81.65 �3.53 31.36 1.47 4.01 3.1933 81.52 �3.81 41.07 86.43 �7.01 45.29 2.57 6.88 7.90 �83.40 �2.37 51.50 1.32 3.95 6.0534 79.23 �13.28 23.68 81.47 �20.58 18.33 3.25 7.45 6.22 80.26 �15.58 27.30 1.90 5.08 3.6235 80.22 �22.49 40.66 80.84 �28.85 41.89 3.19 7.82 7.40 80.30 �25.93 50.32 2.36 5.00 6.2136 77.86 �22.42 11.91 77.95 �28.12 1.77 4.81 7.40 6.14 78.50 �26.07 11.96 2.65 5.79 5.5337 78.09 �17.28 2.15 79.06 �23.03 �12.58 2.81 7.51 2.90 78.95 �18.61 �0.96 3.16 5.87 3.9338 76.42 �13.25 �7.31 77.26 �18.86 �25.10 4.06 6.51 4.79 75.13 �15.26 �13.71 2.87 4.93 3.1339 75.64 �4.49 �9.05 73.69 �7.02 �28.93 2.61 5.55 4.40 74.12 �2.43 �17.43 2.28 5.45 3.2640 75.74 9.02 �7.14 76.62 9.59 �24.29 2.85 6.59 6.06 74.78 14.13 �13.48 2.69 5.53 4.77


the chromaticity of the color matching points for the CRTcolor patches and the printed color patches are both more orless in acceptable ranges and there is no significant differ-ence.

Evaluation Results under Practical Viewing Conditions

Tables VI through X show, for the eight sets of practicalviewing conditions, color matching points between the CRTcolor patches and the printed color patches, along with theacceptable threshold. The measurement values for theprinted color patches were measured with a color luminancemeter for each of the sets of viewing conditions. The chro-maticity color matching points for Tables VI through X areshown in Figures 6 through 9. Figure 6 shows the results forcases 1–3, and Figure 7, the results for cases 4 and 5. Also,Figure 8 shows the results for case 6, and Figure 9, theresults for cases 7 and 8. The difference between cases 1 and8 lies in whether or not the CRT was fitted with a shadinghood, and the results for the two agree well with oneanother. With the exception of low lightness (L* � 60),colorimetric color reproduction is achieved for both cases.With low lightness (L* � 60), for the colors that show atendency for color matching to be on the high chroma side,it is thought that the reduction in the luminance contrast due

to the stimulus and the background being set to the sameluminance had an effect. Moreover, comparing case 7 withcase 0, case 7 was carried out not in a dark room but ratherin a bright room with the same light as ambient light, andthe illuminance of the printed color patches was lowered. Asa result, the lightness color matching point for the CRTcolor patches tended to be lower. The chromaticity of colormatching point, on the other hand, showed virtually nodifference at high lightness (L* � 80), tending to be greaterwhen the lightness was lower. These trends are due to thefact that the reflected glare with the ambient lighting re-duces the brightness contrast between stimulus and back-ground, and that the apparent brightness of the CRT colorpatches was raised due to the low illuminance of the printedcolor patches. With cases 2–6, it is clear that colorimetriccolor reproduction is not realized, showing that it is neces-sary to carry out studies into the corresponding color withthe use of chromatic adaptation formulae or color appear-ance models.

Corresponding Colors from Chromatic AdaptationFormulae and Color Appearance Models

It is clear from the evaluation results under the practicalviewing conditions that there are large discrepancies from

TABLE VIII. Color matching points and acceptable ranges between the printed color patch and the CRT colorpatch for cases 4 and 5.

ColorNo.

Case 4 Case 5



2 65.49 7.38 0.72 55.58 13.39 8.12 1.24 2.03 3.20 55.71 10.78 11.57 4.07 3.04 3.633 67.61 24.36 7.65 55.56 41.28 26.52 2.46 4.07 6.34 56.22 37.27 30.40 2.67 3.95 6.454 67.07 0.68 13.19 58.77 1.79 31.12 1.45 2.50 5.54 58.31 �3.75 36.04 2.03 3.48 6.555 64.88 �8.50 2.05 54.30 �10.47 9.92 1.69 2.06 3.65 56.35 �12.59 12.44 1.78 2.06 3.476 67.11 �13.68 4.37 56.13 �18.15 14.28 0.72 1.57 0.78 57.81 �20.78 20.19 1.50 2.28 5.647 63.86 �5.82 �9.20 56.88 �2.69 �2.43 1.12 2.56 1.50 57.86 �6.46 0.01 1.60 2.96 1.958 65.16 �12.78 �22.22 57.62 �11.12 �11.39 0.15 1.41 0.63 55.80 �13.48 �6.15 2.10 2.13 2.579 63.67 �1.27 �14.97 — — — — — — 56.05 2.26 �4.05 1.46 2.28 2.71

10 63.15 �2.86 �24.87 53.81 3.35 �18.25 0.04 0.80 0.67 56.14 2.80 �12.56 1.84 3.27 4.2711 63.05 19.00 �18.37 — — — — — — 56.06 28.38 �2.81 4.42 3.54 5.1112 63.65 4.98 �10.71 57.35 9.64 �4.59 1.27 1.36 2.12 58.83 9.43 1.76 3.29 3.08 2.5413 64.96 9.39 �3.07 60.31 17.97 4.90 2.64 2.46 1.86 59.22 15.96 11.78 3.41 2.54 3.1214 66.75 24.36 �7.22 59.65 40.06 3.93 3.30 2.99 6.08 61.71 36.15 12.38 4.56 3.89 5.6516 71.62 17.20 9.21 66.12 29.81 26.15 2.31 3.69 3.96 66.00 22.98 34.26 2.17 3.09 4.2117 72.25 8.88 13.38 — — — — — — 64.56 10.25 37.23 1.97 2.12 4.6818 74.77 17.03 23.11 64.88 26.61 50.06 2.54 3.57 5.44 66.25 21.61 63.42 3.63 3.62 10.0419 73.73 2.70 25.07 69.59 5.50 47.17 2.13 3.49 5.96 69.29 �2.38 57.96 1.46 2.80 7.5920 74.77 �6.50 21.90 70.09 �6.34 38.96 1.94 3.58 3.83 70.66 �15.47 48.43 2.76 3.37 6.7021 72.51 �12.68 15.18 66.32 �14.94 30.24 1.37 3.44 4.18 67.33 �23.18 37.76 3.19 3.55 4.7222 74.41 �15.99 18.91 67.19 �21.16 40.94 2.39 2.78 4.94 69.00 �31.14 49.96 3.69 3.32 5.8723 70.63 �15.66 5.31 61.80 �18.29 17.14 1.72 1.83 2.92 62.49 �24.81 24.48 2.41 3.37 5.9424 70.21 �16.22 �5.49 64.93 �16.28 5.51 0.56 4.30 0.95 63.99 �21.18 13.63 3.70 3.40 3.8825 69.12 �11.54 �14.31 65.05 �11.30 �2.31 2.79 3.71 2.34 65.26 �16.54 3.24 3.56 2.85 2.5326 68.32 �1.83 �18.01 63.98 2.53 �7.09 1.40 3.65 1.64 64.52 0.22 �4.66 1.58 4.47 4.3027 67.81 6.67 �13.41 65.34 13.53 �3.03 2.79 3.89 2.85 66.18 11.50 0.59 5.67 3.27 3.4628 71.62 13.92 �8.89 68.87 23.08 3.56 2.35 4.27 3.76 69.81 20.97 9.00 4.92 2.68 2.9930 79.52 9.87 8.90 79.54 18.55 27.32 2.25 3.71 4.79 77.29 12.18 30.70 2.69 3.99 4.1631 81.46 7.93 17.58 79.27 13.97 33.51 1.45 4.21 5.91 79.94 6.45 41.69 1.09 3.56 1.4632 82.03 �0.47 26.28 80.63 4.36 47.27 2.15 3.68 4.70 82.15 �6.09 56.02 2.80 4.39 6.8033 82.99 1.00 37.94 83.32 4.53 58.71 2.10 3.25 5.84 82.70 �5.38 71.04 2.17 4.26 5.3934 79.75 �7.13 21.29 76.80 �5.05 37.72 2.18 3.37 3.87 77.58 �14.30 46.54 2.81 4.53 6.0735 81.68 �12.09 34.08 77.84 �13.07 60.29 2.74 3.09 5.54 78.50 �21.61 70.39 2.94 3.87 8.2136 77.56 �15.31 7.49 72.49 �15.87 21.72 2.47 3.69 2.74 74.33 �22.06 30.09 3.94 4.85 6.0337 76.87 �12.80 �1.51 75.50 �10.80 12.87 3.14 4.44 3.21 73.69 �16.15 19.73 2.62 4.32 4.6938 75.70 �10.79 �10.78 73.65 �8.33 1.87 3.44 3.16 1.62 74.78 �13.37 9.67 2.63 4.01 3.4639 74.85 �3.72 �11.56 72.85 0.89 �1.24 1.92 2.43 0.54 74.08 �2.23 4.61 1.28 4.95 2.9640 76.19 6.90 �8.61 76.23 16.62 4.63 2.95 4.58 2.59 77.54 11.49 13.37 2.97 3.63 2.69


colorimetric color reproduction. We thus predicted theprinted color patch and CRT color patch color matchingpoints using chromatic adaptation formulae and color ap-pearance models, and then compared the prediction andevaluation results. Six types of chromatic adaptation formu-lae and color appearance model were used—CIECAT94,12

CMCCAT97,13 CIECAM97s,14 HUNT94,15,16 NAYA-TANI,17,18 and RLAB.19 For each of the models, the rec-ommended standard values were used for the environmentalparameters (chromatic, brightness, luminance level induc-tion factors, etc.). Note, however, that with regard to theincomplete adaptation proposed by Nayatani et al., weassumed when carrying out the calculations that there isincomplete adaptation for all of the models. Tables XIthrough XIII show the average color differences betweenthe corresponding colors predicted with use of the 6 types ofmodel and the color matching points from the evaluationexperiments, along with the standard deviations. Specifi-cally, Table XI summarizes the results for all of the samplesfor cases 1-8. Tables XII and XIII show the average color

difference and standard deviation for each lightness of colorpatch. As an example of the difference between the corre-sponding color and the color matching point, the results forcase 2 and high lightness (L* � 80) are shown in Figure 10.Regarding the color differences between the correspondingcolors that we calculated using each of the color appearancemodels and the color matching points, the predicted valuesare bright for all of the models and the order is CMC-CAT97, RLAB � NAYATANI � CIECAT94 �CIECAM97 � HUNT94, showing that CMCCAT97 andRLAB are good. And the order is CIECAT94 �CIECAM97 � CMCCAT97 � HUNT94 � RLAB,NAYATANI for the chromaticity. For the overall colordifference, the order is CIECAT94 � CMCCAT97 �RLAB � NAYATANI, CIECAM97 � HUNT94, showingthat the conformity is good. Looking at the results for eachlightness of color patch, it can be seen that the lighter thesample, the greater the tendency toward good conformityfor all of the models. There is no marked difference in thechromaticity according to the lightness of color patch, and it

TABLE IX. Color matching points and acceptable ranges between the printed color patch and the CRT colorpatch for case 6.

ColorNo.

Case 6

Printed color patch Color matching point Acceptable range

L* a* b* L* a* b* �H*ab �L*ab �C*ab

2 66.13 11.29 0.81 63.25 16.09 7.63 2.60 4.83 4.403 68.77 35.52 9.52 62.75 47.10 24.00 2.84 6.02 6.724 66.99 2.38 12.56 60.10 1.90 19.35 1.70 3.68 4.165 65.85 �10.88 2.33 61.38 �12.05 9.63 1.97 4.88 3.736 68.35 �17.77 5.17 62.66 �20.50 14.61 2.15 4.71 5.597 65.28 �7.42 �8.38 62.89 �7.55 �2.52 3.00 4.75 2.548 67.60 �16.83 �20.03 63.38 �19.03 �13.67 2.19 4.14 3.889 65.05 �1.32 �13.99 60.85 1.20 �8.75 1.34 3.57 2.38

10 64.99 �3.61 �23.16 60.96 �0.25 �18.94 1.65 3.52 4.6411 64.71 26.45 �16.49 61.77 37.85 �11.54 4.14 3.77 5.8212 64.88 7.53 �10.09 60.67 11.38 �4.93 2.67 3.38 3.8213 66.00 13.77 �2.60 62.40 19.54 4.25 2.68 3.79 4.6714 68.69 34.17 �5.05 66.43 48.47 3.38 3.78 5.12 5.8516 73.26 25.22 10.24 70.07 32.84 22.15 2.10 5.01 4.5817 73.12 13.85 13.37 73.36 19.47 27.22 2.69 5.00 5.3718 75.78 25.67 24.03 70.32 35.61 50.22 4.21 3.76 8.1619 74.06 5.33 24.59 74.05 5.57 38.28 1.81 4.39 6.0120 75.40 �7.74 21.23 75.31 �9.06 35.87 2.94 3.91 6.6921 73.84 �16.28 15.44 72.48 �20.19 28.24 2.40 4.53 5.4022 75.58 �20.73 19.65 74.32 �25.33 35.72 4.03 4.77 7.2123 72.41 �20.54 6.52 67.78 �23.16 16.84 2.37 3.81 3.7224 72.61 �21.29 �3.73 71.05 �23.24 6.53 2.72 5.19 4.9525 71.52 �15.23 �12.31 68.76 �13.87 �3.98 2.55 3.97 2.2326 70.19 �2.48 �16.33 72.32 1.62 �11.63 1.85 4.40 4.1327 69.51 9.14 �11.89 68.86 15.98 �6.93 3.92 4.87 3.8828 73.29 19.45 �7.21 79.12 30.77 �1.06 2.42 3.93 6.1030 81.21 14.59 9.71 81.15 20.69 21.47 2.51 4.36 4.2931 82.89 12.16 17.86 82.77 17.89 32.29 2.99 2.88 5.1232 83.07 0.79 25.52 86.34 2.83 41.67 2.28 4.52 5.8833 84.08 3.00 37.10 85.22 8.15 55.72 5.51 3.67 7.8834 81.06 �9.12 21.03 85.45 �10.11 35.16 2.74 3.82 4.4935 82.92 �15.50 34.02 85.03 �18.09 54.08 2.55 3.84 5.1736 79.79 �19.89 8.85 77.94 �20.53 18.41 2.46 5.47 2.6837 79.30 �16.82 0.17 80.13 �17.37 9.26 3.22 6.11 3.3838 78.22 �14.41 �8.83 79.87 �13.72 0.65 3.75 5.22 2.7039 77.10 �5.14 �10.07 77.76 �2.22 �4.56 1.96 6.06 1.9140 77.92 9.64 �7.21 81.26 16.53 �0.37 4.39 4.25 3.62


is presumed that this is because the change in colorappearance accompanied by increase in the luminancecontrast between the CRT color patches and the back-ground affected the judgment of lightness matching. Fig-ure 10 shows a representative example of the differencebetween the corresponding color and the color matchingpoint in case 2; it shows that for all of the models, thecorresponding color tends to be shifted in the chromatic-ity direction of the illuminance relative to the colormatching point.

DISCUSSION

Parameter Effects in Chromatic Adaptation Formulaeand Color Appearance Models

It is known that the agreement of colors between differentmedia depends on the viewing conditions.1 We have already

discussed the fact that the tristimulus values are differentwith regard to color matching points between the printedcolors and the monitor colors carried out under eight typesof lighting environment, and that there is a clear discrepancyfrom colorimetric color reproduction. These lighting envi-ronments were selected by imagining the situations in whichcolored images would be evaluated in an office space. Theresults of comparing color matching points with corre-sponding colors predicted by use of the recommended val-ues of parameters for each model indicated that there is atendency for the brightness and chromatic inductions of thebackground to be overestimated, and that there is a whitepoint mismatch. Recommended values of color appearancemodel parameters such as the brightness and chromaticinduction factors of the background have been stipulatedseparately for each of a number of typical viewing conditioncategories. And when the stipulated parameter values areused,20 it has been reported that the color appearance mod-els do not necessarily give good predictions depending on

TABLE X. Color matching points and acceptable ranges between the printed color patch and the CRT colorpatch for case 7.

ColorNo.

Case 7

Printed color patch Color matching point Acceptable range

L* a* b* L* a* b* �H*ab �L*ab �C*ab

2 62.04 8.13 2.61 53.14 11.58 �0.27 0.45 1.45 2.103 62.25 31.83 13.19 51.16 42.15 16.24 1.17 1.55 4.774 62.48 �3.72 18.06 51.47 �1.87 20.39 0.93 1.31 3.015 62.73 �14.32 5.24 51.51 �12.05 3.85 1.10 2.03 1.596 65.05 �22.28 9.17 52.22 �21.20 7.90 0.72 2.04 2.617 62.65 �8.57 �7.03 53.31 �5.26 �9.72 1.01 2.04 1.378 63.94 �16.52 �19.00 53.02 �14.25 �23.45 1.31 2.54 1.099 61.78 �1.60 �13.33 52.06 3.30 �18.78 0.62 0.98 1.41

10 61.20 �2.12 �23.19 51.46 4.15 �31.09 0.24 1.25 0.9711 59.94 26.93 �17.80 50.48 34.45 �22.53 0.83 1.48 2.8712 61.16 6.73 �9.78 51.82 10.98 �12.16 0.30 0.13 2.9213 62.55 11.79 �1.89 53.46 16.38 �3.46 0.87 1.25 2.0214 64.16 32.86 �5.63 53.15 37.37 �7.89 1.27 2.27 2.2916 68.33 21.53 11.89 61.44 27.18 11.31 0.81 0.01 1.8817 68.81 9.46 16.14 59.55 13.18 15.52 1.10 1.59 1.7618 69.63 19.62 31.60 59.18 27.20 40.20 2.06 2.13 4.0019 69.18 �1.01 31.12 — — — — — —20 72.32 �13.11 25.55 61.88 �10.51 26.17 1.19 1.34 2.7221 70.81 �21.27 19.76 61.54 �18.01 18.92 0.32 0.31 1.3322 72.02 �27.75 26.41 61.60 �24.38 26.57 1.02 1.78 2.0123 69.79 �24.08 10.12 59.61 �23.95 9.14 1.11 1.11 1.6824 70.23 �22.54 �1.36 60.96 �19.12 �3.09 0.91 2.80 1.4325 69.32 �14.68 �11.09 61.91 �10.26 �13.70 1.09 0.66 1.2026 67.40 �1.55 �15.98 59.62 3.73 �20.95 0.54 1.72 1.6027 67.48 9.30 �12.14 58.99 14.41 �16.48 0.69 1.50 1.5128 70.40 18.64 �7.86 62.25 24.14 �11.71 1.71 3.11 3.2530 78.87 11.70 9.91 71.35 16.36 8.82 1.95 3.61 2.5831 80.08 8.23 18.87 71.22 12.33 18.03 1.13 0.77 0.7932 80.84 �3.98 27.99 — — — — — —33 81.43 �3.25 41.25 74.03 �1.54 44.67 1.37 1.18 4.6034 79.12 �13.08 23.68 70.19 �11.31 23.03 1.59 3.09 3.4735 79.93 �22.07 40.63 70.30 �21.51 43.65 1.08 1.48 3.3836 77.43 �22.60 11.70 68.82 �22.11 10.62 2.11 3.18 3.2337 77.71 �17.55 1.87 70.85 �16.46 �0.30 0.92 3.10 2.2738 76.58 �13.47 �7.71 68.75 �11.76 �11.53 1.65 2.86 1.9639 75.21 �4.46 �9.48 66.73 0.22 �15.43 0.91 2.98 1.6640 75.54 9.37 �7.47 67.12 14.10 �12.37 1.16 2.63 2.47


FIG. 6. Chromaticity and lightness of color matching point and acceptable range. Arrow indicates the shift of color matchingpoint from printed color patch and arrowhead indicates the color matching points. The axis of ellipses is defined byacceptable range: (a) shows the results for case 1 (left: L* � 60; middle: L* � 70; right: L* � 80); (b) shows the results for case2; and (c) shows the results for case 3.


FIG. 7. Chromaticity and lightness of color matching point and acceptable range. Arrow indicates the shift of color matchingpoint from printed color patch, and arrowhead indicates the color matching points. The axis of ellipses is defined by acceptablerange: (a) shows the results for case 4 (left: L* � 60; middle: L* � 70; right: L* � 80); (b) shows the results for case 5.

FIG. 8. Chromaticity and lightness of color matching point and acceptable range for case 6. Arrow indicates the shift ofcolor matching point from printed color patch, and arrowhead indicates the color matching points. The axis of ellipses isdefined by acceptable range (left: L* � 60; middle: L* � 70; right: L* � 80).


TABLE XI. Average color difference between the corresponding color and the color matching point, and averagestandard deviation of color difference.

CIECAT94 CMCCAT97 CIECAM97 HUNT94 NAYATANI RLAB

�L �E(ab) �E �L �E(ab) �E �L �E(ab) �E �L �E(ab) �E �L �E(ab) �E �L �E(ab) �E

Case 1 Average 4.9 2.1 5.6 1.9 5.4 6.0 9.2 2.9 9.8 10.5 4.1 11.5 4.5 2.0 5.2 1.9 5.3 6.0SD 1.2 1.8 1.5 1.8 2.8 2.8 1.4 2.1 1.8 1.4 2.6 1.9 1.2 1.8 1.6 1.9 2.8 2.8

Case 2 Average 5.5 9.0 10.7 2.3 10.6 11.3 9.6 8.2 13.0 11.2 12.0 16.7 1.4 16.7 16.8 2.3 12.6 13.1SD 1.7 2.2 2.0 2.4 4.4 3.8 1.9 3.2 2.1 1.9 3.2 2.3 1.7 2.3 2.2 2.3 3.9 3.6

Case 3 Average 4.0 6.5 7.9 1.1 10.8 11.3 8.1 9.1 12.6 9.4 11.4 15.1 5.4 9.3 11.0 1.1 11.9 12.4SD 1.9 2.2 2.1 2.8 4.7 4.4 2.3 3.7 3.2 2.4 4.6 4.0 1.9 2.7 2.6 2.9 4.9 4.6

Case 4 Average 8.5 9.6 13.3 5.2 13.0 14.7 12.4 12.0 17.8 13.9 15.5 21.3 4.5 16.0 16.8 5.3 15.7 17.1SD 2.8 4.8 4.4 3.4 6.2 5.4 3.0 5.3 4.1 3.0 5.8 4.6 2.8 4.6 4.6 3.4 6.4 5.8

Case 5 Average 8.1 12.6 15.5 4.8 17.4 18.6 12.0 15.4 20.2 13.8 21.7 26.1 0.7 26.7 26.8 4.9 22.0 22.8SD 2.6 7.2 6.5 3.2 7.8 7.2 2.8 7.4 5.8 2.8 6.9 5.9 2.6 6.5 6.4 3.2 7.6 7.2

Case 6 Average 4.8 8.2 9.8 1.3 10.2 10.9 8.7 9.0 13.0 10.2 11.2 15.6 1.9 12.5 12.9 1.4 11.7 12.2SD 2.5 3.5 3.4 3.1 5.4 5.1 2.7 4.2 3.6 2.7 4.8 4.0 2.5 3.5 3.4 3.1 5.4 5.2

Case 7 Average 9.3 4.1 10.4 9.3 4.7 10.6 7.8 4.8 9.4 7.6 5.0 9.4 9.4 4.2 10.5 9.3 5.0 10.7SD 1.4 2.4 1.8 1.4 2.5 1.8 1.4 2.6 1.9 1.6 2.5 2.0 1.4 2.4 1.8 1.4 2.4 1.8

Case 8 Average 4.6 3.2 5.9 1.6 7.6 8.2 9.0 5.1 10.5 10.4 6.4 12.5 4.3 3.3 5.8 1.6 7.6 8.2SD 1.7 2.6 2.4 2.5 3.8 3.8 2.0 3.1 2.8 2.0 3.6 3.0 1.7 2.7 2.4 2.5 3.9 3.9

Total Average 6.2 6.9 9.8 3.4 10.0 11.4 9.6 8.3 13.3 10.9 10.9 16.0 4.0 11.3 13.2 3.4 11.5 12.8SD 2.8 5.0 4.7 3.7 6.3 5.8 2.7 5.7 4.9 3.0 7.1 6.3 3.3 8.7 7.5 3.7 7.2 6.8

FIG. 9. Chromaticity and lightness of color matching point and acceptable range. Arrow indicates the shift of color matchingpoint from printed color patch, and arrowhead indicates the color matching points. The axis of ellipses is defined byacceptable range: (a) shows the results for case 7 (left: L* � 60; middle: L* � 70; right: L* � 80); (b) shows the results forcase 8.


the viewing method and the viewed images. Moreover,Nayatani et al. have pointed out that it is necessary to giveconsideration to incomplete adaptation to the white point of

the test light, and have proposed introducing an effectiveadapting coefficient into the chromatic adaptation formu-la.21

TABLE XII. Average color difference between the corresponding color and the color matching point for eachlightness level.

Lightness level



V � 5 Case 1 5.1 2.2 5.8 3.4 6.0 7.1 10.0 3.5 10.8 11.3 4.9 12.5 4.8 2.1 5.5 3.4 6.0 7.1Case 2 6.3 7.6 9.9 4.6 7.1 8.7 11.1 5.3 12.6 12.6 8.9 15.5 2.3 15.1 15.3 4.5 9.0 10.1Case 3 5.3 6.9 8.9 3.6 11.6 12.4 10.0 9.3 14.1 11.3 11.8 16.9 6.7 10.1 12.3 3.7 12.6 13.3Case 4 10.6 7.8 13.6 8.6 9.7 13.5 15.0 9.0 18.0 16.5 11.9 20.7 6.6 14.1 15.7 8.5 12.0 15.0Case 5 9.8 9.2 13.8 7.8 12.1 14.7 14.3 10.3 18.1 15.9 16.7 23.2 2.5 23.2 23.4 7.7 16.4 18.3Case 6 6.4 6.8 9.4 4.2 7.6 9.0 10.8 6.8 13.0 12.3 8.7 15.3 3.6 11.2 11.8 4.1 8.9 10.0Case 7 10.3 4.7 11.6 10.3 5.3 11.8 8.8 5.4 10.6 9.0 5.6 10.8 10.4 4.8 11.7 10.3 5.5 11.9Case 8 5.4 4.3 7.2 3.8 8.8 9.7 10.4 6.4 12.4 11.9 7.7 14.5 5.2 4.6 7.1 3.8 8.8 9.7Total 7.4 6.1 9.9 5.7 8.5 10.9 11.2 7.0 13.6 12.5 9.5 16.1 5.3 10.4 12.7 5.7 9.9 11.9


V � 7 Case 1 4.5 1.9 5.1 �0.1 4.2 4.4 7.6 1.9 7.8 9.4 2.9 9.9 4.1 1.7 4.6 �0.1 4.2 4.4Case 2 5.1 8.8 10.4 0.3 12.2 12.4 8.5 9.2 12.7 10.1 13.3 16.8 0.9 16.6 16.8 0.4 14.2 14.4Case 3 2.4 7.2 7.7 �2.1 11.2 11.8 5.8 10.4 12.0 7.0 12.4 14.3 3.8 9.9 10.7 �2.2 12.6 13.2Case 4 6.4 9.9 12.0 1.8 14.9 15.1 9.6 13.7 16.9 11.2 17.8 21.2 2.2 16.1 16.3 1.9 18.2 18.4Case 5 6.0 13.3 14.8 1.2 20.4 20.5 9.1 18.2 20.6 11.1 24.8 27.3 �1.6 27.3 27.4 1.5 25.4 25.5Case 6 3.4 8.3 9.2 �1.5 11.5 11.7 6.6 10.0 12.3 8.2 12.7 15.4 0.5 12.6 12.7 �1.4 13.3 13.5Case 7 8.4 3.2 9.1 8.2 3.8 9.2 6.7 3.9 7.9 6.2 4.1 7.6 8.4 3.3 9.2 8.3 4.1 9.4Case 8 3.7 1.9 4.5 �1.0 6.3 6.7 7.4 3.9 8.5 8.8 5.2 10.4 3.4 2.1 4.3 �0.9 6.3 6.7Total 5.0 6.9 9.1 0.8 10.6 11.5 7.7 9.0 12.5 9.1 11.7 15.5 2.7 11.3 12.8 0.8 12.4 13.2

TABLE XIII. Average standard deviation of color differences between the corresponding color and the colormatching point.

Lightness level







In our current research, we carried out studies into opti-mal values for the brightness induction factor, the chromaticinduction factor, and the effective adapting coefficient byusing the results of visual color matching between printed

color patches and monitor colors under the eight types oflighting environment shown in Table I. In addition, wecompared the performances of five types of color appear-ance model—CIECAT94, CMCCAT97, CIECAM97,HUNT94, and NAYATANI—based on the correspondingcolors predicted using the optimized parameters. However,for the CIECAT94, CMCCAT97, and NAYATANI models,the effective adapting coefficient was the only parameter.

Parameters

The parameters used in the various color appearance modelsare shown in Table XIV, along with the values of these

TABLE XIV. Types of parameter and simulationranges.

Model

Brightness inductionfactor of

background(c or Nb)

ParameterChromatic induction

factor ofbackground

(Nc)

Effectiveadapting

coefficient�

CIECAT94 — — 0�1.0CIECAM97s 0.39 � 0.69 � 0.89 0.6�1.0�1.2 0�1.0HUNT94 10 � 300 0.5�1.0 0�1.0NAYATANI — — 0�1.0

TABLE XV. Parameter effect about brightness induction factor and chromatic induction factor of background forCIECAM97s.

CIECAM case 1 CIECAM case 2 CIECAM case 3 CIECAM case 4

Nc �L �E(ab) �E(Lab) Nc �L �E(ab) �E(Lab) Nc �L �E(ab) �E(Lab) Nc �L �E(ab) �E(Lab)

1.2 9.17 6.84 11.63 1.2 9.64 10.76 15.04 1.2 8.13 11.27 14.25 1.21.1 9.17 4.99 10.62 1.1 9.64 9.47 14.02 1.1 8.14 10.12 13.33 1.1 12.35 12.87 18.541 9.18 2.90 9.79 1 9.64 8.19 13.02 1 8.15 9.12 12.58 1 12.36 12.02 17.800.9 9.19 2.06 9.49 0.9 9.64 7.09 12.20 0.9 8.16 8.66 12.28 0.9 12.36 11.16 17.080.8 9.20 3.99 10.27 0.8 9.64 6.52 11.94 0.8 8.18 9.36 12.81 0.8 12.37 10.42 16.530.7 9.22 8.20 12.67 0.7 9.64 8.06 13.01 0.7 8.20 11.39 14.59 0.7 12.38 10.29 16.490.6 9.25 14.12 17.19 0.6 9.64 12.76 16.38 0.6 8.23 15.55 18.30 0.6 12.39 11.81 17.74

c �L �E(ab) �E(Lab) c �L �E(ab) �E(Lab) c �L �E(ab) �E(Lab) c �L �E(ab) �E(Lab)

0.89 32.44 3.12 32.64 0.89 32.90 6.05 33.54 0.89 31.30 8.41 32.52 0.89 35.68 10.62 37.380.79 22.11 2.02 22.23 0.79 22.57 6.77 23.67 0.79 21.00 8.37 22.81 0.79 25.33 11.15 27.940.69 9.18 2.90 9.79 0.69 9.64 8.19 13.02 0.69 8.15 9.12 12.58 0.69 12.36 12.02 17.800.59 �6.90 5.79 9.31 0.59 �6.47 10.38 12.54 0.59 �7.84 10.74 13.78 0.59 �3.82 13.23 14.180.49 �26.79 8.58 28.34 0.49 �26.41 12.83 29.84 0.49 �27.59 12.74 30.83 0.49 �23.85 14.65 28.850.39 �51.60 7.80 52.30 0.39 �51.28 12.36 53.02 0.39 �52.22 12.76 54.03 0.39 �48.78 14.45 51.47

CIECAM case 5 CIECAM case 6 CIECAM case 7 CIECAM case 8


1.1 12.00 16.26 21.05 1.2 8.66 11.07 14.80 1.2 8.94 8.98 12.881 11.99 15.40 20.24 1.1 8.65 10.03 13.88 1.1 7.75 5.72 10.00 1.1 8.95 7.15 11.680.9 11.99 14.48 19.39 1 8.65 8.99 12.96 1 7.76 4.81 9.39 1 8.96 5.08 10.550.8 11.99 13.53 18.54 0.9 8.65 8.11 12.19 0.9 7.78 4.75 9.23 0.9 8.97 3.60 9.830.7 11.99 12.66 17.85 0.8 8.65 7.72 11.84 0.8 7.80 5.76 9.92 0.8 8.99 4.13 10.110.6 11.99 12.40 17.83 0.7 8.65 8.73 12.62 0.7 7.83 8.42 11.91 0.7 9.01 7.14 12.020.5 12.00 14.93 20.03 0.6 8.65 12.52 15.57 0.6 7.86 13.25 15.82 0.6 9.04 12.78 16.20

c �L �E(ab) �E(Lab) c �L �E(ab) �E(Lab) c �L �E(ab) �E(Lab) c �L �E(ab) �E(Lab)

0.89 35.28 13.13 37.95 0.89 31.85 7.82 32.88 0.89 30.65 4.77 31.07 0.89 32.08 3.29 32.280.79 24.94 14.09 29.15 0.79 21.57 8.12 23.20 0.79 20.40 4.44 20.93 0.79 21.81 3.45 22.150.69 11.99 15.40 20.24 0.69 8.65 8.99 12.96 0.69 7.76 4.81 9.39 0.69 8.96 5.08 10.550.59 �4.14 17.08 17.90 0.59 �7.49 10.49 13.41 0.59 �7.77 6.23 10.36 0.59 �7.02 7.90 11.040.49 �24.12 18.93 31.68 0.49 �27.51 12.41 30.87 0.49 �26.82 7.87 28.24 0.49 �26.80 10.59 29.150.39 �49.01 19.46 53.52 0.39 �52.40 12.66 54.41 0.39 �51.07 9.12 52.32 0.39 �51.48 9.40 52.54

FIG. 10. Result of color difference between color matchingpoints and corresponding colors for L* � 80. Arrow indicatesthe shift of corresponding color from printed color patch,and arrowhead indicates the chromaticity of correspondingcolor.


parameters used in the predictions. The recommended valuesfor the parameters under the viewing conditions shown inTable XIV are as follows: CIECAT94: � � 1; CMCCAT97:� � 1; CIECAM97: c � 0.69, Nc � 1, � � 1; HUNT94:Nb � 75, Nc � 1, � � 1; NAYATANI: � � 1.

Brightness Induction Factor of the Background

We predicted the corresponding colors for the monitorcolors by using the tristimulus values of the printed color

patch for which color matching had been carried out underthe viewing conditions shown in Table I. We found theparameters for which the color difference (CIELAB) be-tween the color matching point of printed color and thecorresponding color is minimal. However, when the valuesof the brightness or chromatic induction factor werechanged separately, broadly speaking, predicting the corre-sponding color only changed the brightness or the chroma-ticity. Therefore, we can assume a parameter effect of the

FIG. 11. Lightness difference between the color matchingpoint and the corresponding color against various bright-ness induction factors about CIECAM97s.

FIG. 12. Lightness difference between the color matchingpoint and the corresponding color against various bright-ness induction factors about HUNT94.

TABLE XVI. Parameter effect about brightness induction factor and chromatic induction factor of the back-ground for HUNT94.

Hunt case 1 Hunt case 2 Hunt case 3 Hunt case 4


1.0 10.51 4.12 11.50 1 11.17 12.02 16.65 1 9.41 11.41 15.14 1 13.90 15.46 21.280.9 10.51 2.41 10.89 0.9 11.17 10.92 15.81 0.9 9.42 10.83 14.72 0.9 13.91 14.96 20.810.8 10.51 3.08 11.12 0.8 11.16 9.94 15.31 0.8 9.42 11.24 15.01 0.8 13.91 14.62 20.510.7 10.51 6.72 12.87 0.7 11.16 10.44 15.87 0.7 9.43 12.93 16.43 0.7 13.92 14.78 20.630.6 10.52 12.55 16.84 0.6 11.15 14.30 18.65 0.6 9.44 16.39 19.61 0.6 13.93 16.11 21.820.5 10.53 21.08 24.01 0.5 11.14 22.04 25.10 0.5 9.46 23.02 25.83 0.5 13.95 20.07 25.29

Nb �L �E(ab) �E(Lab) Nb �L �E(ab) �E(Lab) Nb �L �E(ab) �E(Lab) Nb �L �E(ab) �E(Lab)

300 47.02 6.41 47.57 300 47.95 13.22 49.93 300 45.68 12.54 47.62 300 51.02 16.04 53.81150 26.45 5.70 27.21 150 27.22 12.85 30.34 150 25.25 12.11 28.31 150 30.08 15.88 34.4675 10.51 4.12 11.50 75 11.17 12.02 16.65 75 9.41 11.41 15.14 75 13.90 15.46 21.2850 2.62 3.00 4.35 50 3.23 11.36 12.07 50 1.58 11.07 11.59 50 5.90 15.13 16.7325 �9.16 2.56 9.65 25 �8.61 9.94 13.42 25 �10.11 11.33 15.46 25 �6.02 14.49 16.0110 �22.46 7.11 24.13 10 �21.98 10.31 24.77 10 �23.32 14.78 27.86 10 �19.46 13.89 24.07



1.0 13.76 21.74 26.12 1 10.22 11.21 15.62 1 7.63 5.02 9.38 1 10.42 6.44 12.540.9 13.76 21.24 25.65 0.9 10.22 10.43 14.92 0.9 7.63 4.92 9.19 0.9 10.42 4.50 11.590.8 13.77 20.78 25.23 0.8 10.21 10.01 14.54 0.8 7.64 5.91 9.94 0.8 10.43 4.27 11.380.7 13.77 20.49 25.03 0.7 10.21 10.52 14.99 0.7 7.65 8.81 12.16 0.7 10.43 6.28 12.700.6 13.77 20.86 25.48 0.6 10.20 13.33 17.30 0.6 7.66 14.04 16.48 0.6 10.44 11.60 16.370.5 13.78 23.17 27.78 0.5 10.19 19.98 22.83 0.5 7.68 22.31 23.99 0.5 10.46 20.20 23.50

Nb �L �E(ab) �E(Lab) Nb �L �E(ab) �E(Lab) Nb �L �E(ab) �E(Lab) Nb �L �E(ab) �E(Lab)

300 50.74 22.22 55.78 300 47.94 11.98 49.67 300 40.89 6.93 41.66 300 46.70 11.27 48.24150 29.89 22.10 37.63 150 26.63 11.79 29.49 150 22.30 5.97 23.33 150 26.30 8.00 27.7375 13.76 21.74 26.12 75 10.22 11.21 15.62 75 7.63 5.02 9.38 75 10.42 6.44 12.5450 5.79 21.43 22.52 50 2.13 10.77 11.45 50 0.28 4.85 5.24 50 2.56 5.27 6.3325 �6.10 20.75 21.85 25 �9.92 9.97 14.31 25 �10.82 6.05 12.65 25 �9.17 4.20 10.4010 �19.50 19.47 27.84 10 �23.48 9.62 25.57 10 �23.37 10.46 26.31 10 �22.41 7.72 24.15


brightness induction factor that is independent of otherfactors. And so this study was carried out in the correspond-ing color only in the case of a changing brightness inductionfactor, because the chromatic induction factor and the ef-fective adapting coefficient were fixed at their recom-mended values. The results for the CIECAM97s and

HUNT94 models are shown in Tables XV and XVI. Figures11 and 12 show graphs of the lightness difference (�L*)between the color matching point of prined color and thecorresponding color against the brightness induction factor.For both the CIECAM97s and HUNT94 models, we founda correlation between the parameter value and the lightness

FIG. 13. Chromaticity difference between the color match-ing point and the corresponding color against various chro-matic induction factors about CIECAM97s.

FIG. 14. Chromaticity difference between the color match-ing point and the corresponding color against various chro-matic induction factors about HUNT94.

TABLE XVII. Parameter effect about adapting coefficients for CIECAT94.

CIECAT case 1 CIECAT case 2 CIECAT case 3 CIECAT case 4

� �L �E(ab) �E(Lab) � �L �E(ab) �E(Lab) � �L �E(ab) �E(Lab) � �L �E(ab) �E(Lab)

1 4.90 2.13 5.56 1 5.49 8.96 10.70 1 3.96 6.51 7.86 1 8.54 9.59 13.270.7 4.90 2.09 5.55 0.7 5.49 3.51 6.85 0.7 3.96 3.72 5.78 0.7 8.54 4.88 10.000.5 4.90 2.07 5.54 0.5 5.49 2.80 6.39 0.5 3.96 3.45 5.75 0.5 8.54 8.21 12.160.3 4.90 2.06 5.53 0.3 5.49 4.97 7.62 0.3 3.96 5.13 6.93 0.3 8.54 13.14 16.080 4.90 2.05 5.53 0 5.49 9.22 10.93 0 3.96 9.17 10.24 0 8.55 21.05 22.99

CIECAT case 5 CIECAT case 6 CIECAT case 7 CIECAT case 8


1 8.14 12.60 15.50 1 4.80 8.16 9.80 1 9.35 4.11 10.43 1 4.56 3.18 5.910.7 8.13 8.35 12.07 0.7 4.79 3.40 6.40 0.7 9.35 3.77 10.29 0.7 4.56 3.15 5.870.5 8.13 13.44 16.21 0.5 4.79 3.66 6.43 0.5 9.35 3.60 10.22 0.5 4.56 3.15 5.860.3 8.14 19.78 21.81 0.3 4.79 6.08 8.12 0.3 9.35 3.48 10.18 0.3 4.56 3.16 5.850 8.16 29.08 30.45 0 4.79 10.64 11.99 0 9.35 3.40 10.14 0 4.56 3.19 5.85

TABLE XVIII. Parameter effect about adapting coefficients for CAMCAT97.

CAMCAT97 case 1 CAMCAT97 case 2 CAMCAT97 case 3 CAMCAT97 case 4


1 1.86 5.35 5.99 1 2.26 10.64 11.31 1 1.08 10.80 11.33 1 5.23 12.96 14.670.7 1.86 5.35 5.99 0.7 2.24 6.93 7.78 0.7 1.04 8.91 9.54 0.7 5.10 7.03 9.250.5 1.86 5.35 5.99 0.5 2.25 6.16 6.98 0.5 1.03 8.03 8.72 0.5 5.09 8.34 10.140.3 1.86 5.36 5.99 0.3 2.27 6.35 7.12 0.3 1.03 7.62 8.29 0.3 5.14 11.16 12.650 1.86 5.36 6.00 0 2.33 7.87 8.56 0 1.05 8.03 8.70 0 5.28 16.63 17.91

CAMCAT97 case 5 CAMCAT97 case 6 CAMCAT97 case 7 CAMCAT97 case 8


1 4.83 17.40 18.61 1 1.34 10.20 10.88 1 9.26 4.73 10.62 1 1.55 7.61 8.150.7 4.54 9.62 11.11 0.7 1.30 6.53 7.56 0.7 9.26 4.38 10.47 0.7 1.55 7.59 8.130.5 4.56 12.52 13.70 0.5 1.30 6.48 7.33 0.5 9.26 4.21 10.39 0.5 1.55 7.58 8.120.3 4.67 16.54 17.50 0.3 1.32 7.35 8.06 0.3 9.26 4.07 10.34 0.3 1.55 7.57 8.110 4.94 22.61 23.46 0 1.38 9.75 10.30 0 9.26 3.96 10.29 0 1.55 7.56 8.10


difference (�L*), with the optimal values being c � 0.61 �0.63 for the CIECAM97s and Nb � 35 � 50 for theHUNT94. These optimal values are lower than the recom-mended values for the models and are close to the recom-mended values for a dim surround. In this case, we per-formed color matching experiments under bright lightingenviroments and with monitor colors having a three-partstructure consisting of a white border, a background, and atest color that looked like the surface color mode. Therefore,we presumed that the color appearance of monitor colorsdepends on the stipulations. There were virtually no differ-ences in the optimal values between the different sets ofviewing conditions, although the optimal values for cases 4and 5 were lower than those for the other cases. With cases4 and 5, the difference in color temperature between theilluminant for printed color and the monitor white was large,so we presumed that there were effects due to the visualclarity received from the white on the prints (4,200 K). Thissuggests that it is necessary to consider the effects of in-complete adaptation on the brightness induction factor.

The mean optimal values over the eight sets of viewingconditions are c � 0.625 for CIECAM97s and Nb � 42 forHUNT94.

Chromatic Induction Factor of the Background

Similar to the procedure used with the brightness induc-tion factor of the background, only the chromatic inductionfactor of the background was changed. Therefore, thebrightness induction factor of the background and the ef-fective adapting coefficient were fixed at their recom-mended values. The color difference between the colormatching point of printed color and the corresponding colorfor this case is shown in Tables XV and XVI. And therelationship between the chromatic induction factor and thechromaticity difference (�E*ab) between the color matchingpoint and the corresponding color is shown in Figures 13and 14. With the CIECAM97s model, the results vary fordifferent sets of viewing conditions, and the optimal valuefor cases 4 and 5 tend to be lower than for the other cases.For other cases, the chromatic induction factor for which thechromaticity difference is a minimum lies in the range Nc �0.8 � 1.0, and the effect of the parameter is larger than thatin cases 4 and 5. As with the brightness induction factor, theoptimal value of the chromatic induction factor is close tothe value for a dim or dark surround, showing that chro-matic induction is acting excessively. With cases 4 and 5,

TABLE XIX. Parameter effect about adapting coefficients for CIECAM97s.

CIECAM97 case 1 CIECAM97 case 2 CIECAM97 case 3 CIECAM97 case 4


1.0 �0.86 2.11 2.77 1 �0.44 7.58 7.85 1 �1.83 8.93 9.46 1 2.25 11.36 12.110.7 �0.86 2.11 2.77 0.7 �0.46 2.59 3.17 0.7 �1.85 5.46 6.26 0.7 2.09 4.74 5.820.5 �0.86 2.12 2.77 0.5 �0.44 3.84 4.35 0.5 �1.85 3.79 4.78 0.5 2.07 9.29 10.020.3 �0.86 2.13 2.78 0.3 �0.42 6.88 7.20 0.3 �1.85 3.74 4.73 0.3 2.10 15.04 15.570 �0.86 2.16 2.80 0 �0.36 11.55 11.73 0 �1.82 6.95 7.57 0 2.22 23.42 23.76

CIECAM97 case 5 CIECAM97 case 6 CIECAM97 case 7 CIECAM97 case 8


1.0 1.90 15.00 15.52 1 �1.43 8.30 8.88 1 �1.95 4.92 5.54 1 �1.01 3.91 4.580.7 1.59 8.52 9.20 0.7 �1.49 3.07 4.28 0.7 �1.95 4.46 5.14 0.7 �1.02 3.81 4.500.5 1.60 15.88 16.24 0.5 �1.49 4.32 5.34 0.5 �1.95 4.20 4.91 0.5 �1.02 3.76 4.450.3 1.69 23.20 23.48 0.3 �1.48 7.47 8.11 0.3 �1.95 3.99 4.73 0.3 �1.02 3.72 4.410 1.96 32.96 33.16 0 �1.43 12.40 12.81 0 �1.96 3.79 4.53 0 �1.02 3.68 4.37

TABLE XX. Parameter effect about adapting coefficients for HUNT94.



1.0 �1.38 5.36 5.96 1 �0.80 9.82 10.17 1 �1.54 11.70 12.12 1 1.86 14.42 15.010.7 �1.38 5.36 5.95 0.7 �0.80 5.49 6.21 0.7 �1.51 6.98 7.64 0.7 1.77 6.88 7.990.5 �1.38 5.36 5.94 0.5 �0.80 7.64 8.11 0.5 �1.50 4.26 5.28 0.5 1.68 14.64 15.170.3 �1.38 5.36 5.94 0.3 �0.81 12.18 12.44 0.3 �1.48 3.46 4.74 0.3 1.58 23.10 23.420 �1.39 5.37 5.94 0 �0.83 18.83 18.99 0 �1.47 7.33 8.04 0 1.44 35.42 35.62



1.0 1.76 20.32 20.69 1 �1.10 9.85 10.42 1 �3.46 �8.49 9.60 1 �0.57 4.60 5.200.7 1.65 12.18 12.72 0.7 �1.14 3.56 4.72 0.7 �3.48 8.13 9.28 0.7 �0.57 4.36 4.990.5 1.54 24.81 25.07 0.5 �1.17 5.54 6.36 0.5 �3.49 7.97 9.12 0.5 �0.58 4.21 4.860.3 1.42 36.77 36.94 0.3 �1.21 9.63 10.16 0.3 �3.51 7.87 9.00 0.3 �0.58 4.07 4.730 1.45 52.69 52.81 0 �1.27 16.15 16.47 0 �3.53 7.78 8.91 0 �0.58 3.89 4.57


because there are large, incomplete adaptation effects due tothe difference in the white point for the prints and themonitor, the effect of the parameter is small. Compared withthe brightness induction factor, the effect of the chromaticinduction factor is small, because there is no marked changein the chromaticity difference between the case in which theoptimal value and that in which the recommended value isused. With the HUNT94, the extent of parameter effectdiffers according to the viewing conditions, but the trend islargely the same as that obtained with the CIECAM97s. Theoptimal value for which the chromaticity difference is aminimum lies in the range Nc � 0.8 � 0.9, which corre-sponds to a dark surround. However, there is little differ-ence when the recommended value of Nc � 1.0 is used.

The mean optimal values over the eight sets of viewingconditions are Nc � 0.85 for both CIECAM97s andHUNT94.

Effective Adapting Coefficient

The color difference between the color matching point ofprinted color and the corresponding color in the case of theeffective adapting coefficient is introduced in Tables XVII

through XXI. We calculated the corresponding color forCIECAM97s and HUNT94 using the average optimal val-ues over the eight sets of viewing conditions for the bright-ness and chromatic induction factors of the background. Theeffective adapting coefficient was used to correct for incom-plete adaptation to the chromaticity of the white point of theprint surface and the monitor, so it had virtually no effect onthe lightness/brightness difference between the color match-ing point of printed color and the corresponding color. Therelationship between the effective adapting coefficient andthe chromaticity difference between the color matchingpoint and the corresponding color is shown in Figures 15through 19. In each of the figures, for cases 1, 7, and 8, thewhite point is the same for the print surface and the monitor,so there is no change in the chromaticity difference uponchanging the effective adapting coefficient. The parametereffect shows the same kind of characteristics for all of theCIECAT94, CMCCAT97, CIECAM97s, and HUNT94, andthe chromaticity difference becomes a minimum around� � 0.6 � 0.7. However, there tends to be a slight shift toa lower value of � for the NAYATANI. The parametereffects of the effective adapting coefficient are marked forcases 4 and 5, in which the print white point is 4,200 K. Inthese cases, the white point of print surface differs consid-

FIG. 15. Chromaticity difference between the color match-ing point and the corresponding color against various adapt-ing coefficients about CIECAT94.

FIG. 16. Chromaticity difference between the color match-ing point and the corresponding color against various adapt-ing coefficients about CMCCAT97.

TABLE XXI. Parameter effect about adapting coefficients for NAYATANI.

NAYATANI case 1 NAYATANI case 2 NAYATANI case 3 NAYATANI case 4


1.0 4.53 2.03 5.19 1 1.44 16.68 16.84 1 5.40 9.32 10.96 1 4.47 15.96 16.800.7 4.54 1.99 5.18 0.7 2.70 7.92 8.59 0.7 4.75 4.92 7.09 0.7 5.72 5.03 8.010.5 4.54 1.97 5.18 0.5 3.56 3.18 5.20 0.5 4.32 3.16 5.80 0.5 6.58 6.49 9.470.3 4.55 1.95 5.17 0.3 4.45 4.11 6.28 0.3 3.90 4.39 6.42 0.3 7.47 12.16 14.680 4.55 1.94 5.17 0 5.83 10.71 12.38 0 3.28 9.42 10.23 0 8.85 22.20 24.16

NAYATANI case 5 NAYATANI case 6 NAYATANI case 7 NAYATANI case 8


1.0 0.69 26.68 26.81 1 1.93 12.48 12.88 1 9.39 4.22 10.51 1 0.82 10.15 10.430.7 3.00 7.63 8.67 0.7 2.79 5.35 6.57 0.7 9.37 3.84 10.34 0.7 0.79 10.07 10.350.5 4.64 9.68 11.13 0.5 3.38 3.30 5.28 0.5 9.36 3.64 10.26 0.5 0.78 10.02 10.300.3 6.37 17.65 19.14 0.3 3.98 5.60 7.28 0.3 9.35 3.51 10.19 0.3 0.76 9.97 10.250 9.14 31.39 32.93 0 4.90 11.45 12.77 0 9.33 3.41 10.13 0 0.74 9.91 10.19


erably to 5,500 � 6,500 K, which is the color temperaturethat Hunt and Winter22 say is perceived as white, and thisshows that adaptation with large color temperature differ-ence is not completely realized. The optimal value � 0.7agrees fairly well with the experimental results of Yano etal.23 and Kato.24 With cases 2, 3, and 6, for which the effectsof the effective adapting coefficient are small, the optimalvalue varies somewhat according to the color appearancemodel. However, even if � � 0.7 is used, there is no markedchange in the color difference between the cases in whichthe optimal value for respectively viewing conditions isused, so the effective adapting coefficient � � 0.7 can forpractical purposes be used regardless of the viewing condi-tions.

CONCLUSIONS

1. The tristimulus values of the color matching points forpainted color patches and CRT color patches placed in adark room under the same viewing conditions more orless matched. Even with a color chart/CRT/printer serialsystem, with the color patches used as the inputs, more orless the same results were obtained.

2. The results for cases 2 to 6, in which reflective sampleswere illuminated with the ambient light in a bright room,showed clearly that colorimetric color reproduction isnot realized.

3. As a result of comparing color matching points withcorresponding colors predicted using chromatic adapta-tion formulae and color appearance models, it was foundthat the order from best to worst agreement wasCIECAT94 RLAB NAYATANI CIECAM97 HUNT94.

4. The results for the corresponding colors showed that theyare brighter than the color matching points, and theretends to be a shift in the chromaticity direction of thechromaticity coordinate of the illuminant. This suggeststhat it is necessary to carry out studies on the values ofthe parameters used in the prediction, such as the bright-ness induction factor, and on incomplete adaptation.

5. We studied the effects of the parameters of color appear-ance models by using data from color matching experi-ments and comparing samples having a three-part struc-ture consisting of a white border, a background, and atest color. The parameters studied were the brightnessand chromatic induction factors of the background andthe effective adapting coefficient. We found that theeffects of the parameters for the CIECAM97s andHUNT94 show more or less the same trends, with theoptimal values of the parameters being slightly lowerthan the recommended values for the models. Moreover,the results indicate that it is possible to predict accuratelythe observation results by introducing the effects ofincomplete adaptation to the white point. When the op-timal parameter values are used, the color differencebetween the color matching point of printed color and thecorresponding color averaged over the eight sets of view-ing conditions is �E* 5.1 for the CIECAM97s (Nc �0.85, c � 0.625, and � � 0.7) and �E* 7.4 for theHUNT94 (Nc � 0.85, Nb � 42, and � � 0.7). With theCIECAT94, CMCCAT97, and NAYATANI, only theeffective adapting coefficient can be used, but we foundthat the effective adapting coefficient has large effects

FIG. 19. Chromaticity difference between the color match-ing point and the corresponding color against various adapt-ing coefficients about NAYATANI.

FIG. 17. Chromaticity difference between the color match-ing point and the corresponding color against various adapt-ing coefficients about CIECAM97s.

FIG. 18. Chromaticity difference between the color match-ing point and the corresponding color against various adapt-ing coefficients about HUNT94.


under conditions in which it is presumed difficult toperceive being white after adaptation, so the optimalvalue is � 0.7. When using the optimal parametervalue, the color difference between the color matchingpoint of printed color and the corresponding color aver-aged over the eight sets of viewing conditions are �E* 7.8 for the CIECAT94 (� � 0.7), �E* 8.7 for theCMCCAT97(� � 0.7), and �E* 7.8 for the NAYA-TANI (� � 0.5).

1. Braun KM, Fairchild MD. Testing five color-appearance models forchanges in viewing conditions. Color Res Appl 1997;22:165–173.

2. Lou MR, Clarke AA, Rhodes PA, Schappo A, Scrivener SAR, Tait CJ.Quantifying colour appearance: Part I. LUTCHI colour appearancedata. Color Res Appl 1991;16:166–180.

3. Lou MR, Clarke AA, Rhodes PA, Schappo A, Scrivener SAR, Tait CJ.Quantifying colour appearance: Part II. Testing colour models perfor-mance using LUTCHI colour appearance data. Color Res Appl 1991;16:181–197.

4. Lou MR, Gao XW, Rhodes PA, Xin HJ, Clarke AA, Scrivener SAR.Quantifying colour appearance: Part III. Supplementary LUTCHI col-our appearance data. Color Res Appl 1993;18:98–113.

5. Mori L, Sobagaki H, Komatsubara H, Ikeda K. Field trials on CIEchromatic adaptation formula. CIE Proceedings 22nd Session Mel-bourne, Division 1; 1991. p 55–58.

6. Alessi PJ. CIE guidelines for coordinated research on evaluation ofcolour appearance models for reflection print and self-luminous dis-play image comparisons. Color Res Appl 1994;19:48–58.

7. Braun KM, Fairchild MD, Alessi PJ. Viewing techniques for cross-media image comparisons. Color Res Appl 1996;21:6–17.

8. ISO DIS/3668: Paint and varnishes—Visual comparison of the colourof paint. ISO, 1996.

9. ISO WD/3664: Viewing condition—For graphic technology and pho-tography. ISO, 1997.

10. CIE Publication No. 101. Parametric effects in colour-difference eval-uation. Vienna: Central Bureau of the CIE; 1993.

11. Guilford JP. Psychometric methods. New York, McGraw-Hill; 1954.12. CIE Publication No.109. A method of predicting corresponding col-

ours under different chromatic and illuminance adaptations. Vienna:Central Bureau of the CIE; 1994.

13. Luo MR, Hunt RWG. A chromatic adaptation transform and a colourinconstancy index. Color Res Appl 1998;23:154–8.

14. Fairchild MD. Progress report of CIE TC1-34 with an introduction ofthe CIECAM97’s colour appearance model. Proceedings of the CIEExpert Symposium ’97 on Colour Stand Image Technology, CIE Pub.X014, p 77–80;1998.

15. Hunt RWG. Revised colour-appearance model for related and unre-lated colours. Color Res Appl 1991;16:146–165.

16. Hunt RWG. An improved predictor of colourfulness in a model ofcolour vision. Color Res Appl 1994;19:23–33.

17. Nayatani Y, Takahama K, Sobagaki H. Prediction of color appearanceunder various adapting conditions. Color Res Appl 1986;11:62–71.

18. Nayatani Y, Sobagaki H, Hashimoto K, Yano T. Lightness depen-dency of chroma scales of a nonlinear color-appearance model and itslatest formulation. Color Res Appl 1995;20:156–167.

19. Fairchild MD. Refinement of the RLAB color space. Color Res Appl1996;21:338–346.

20. Hseue TC, Shen YC, Chen PC, Hsu WH, Liu YT. Cross-mediaperformance evaluation of color models for unequal luminance levelsand dim surround. Color Res Appl 1998;23:169–177.

21. Nayatani Y, Sobagaki H, Hashimoto K, Yano T. Field trials of non-linear color-appearance model. Color Res Appl 1997;22:240–258.

22. Hunt RWG, Winter LM. Colour adaptation in picture-viewing situa-tion. J Phot Sci 1975;23:112–115.

23. Yano T, Hashimoto K, Nayatani Y. Color image reproduction usingCIE chromatic adaptation transform. J Illum Eng Inst Jpn 1998;82:84–90.

24. Kato N. Practical method for appearance match between soft copy andhard copy. SPIE Publication No. 2170, p 170–181, 1994.


Visual color matching under various viewing...

Documents

Transcript of Visual color matching under various viewing...