Color Calculator

Xiaoyan Song

xas2911@cis.rit.edu

Feb.21,2003

Feb.21,2003 Xiaoyan Song 2

Outline

Motivation Project Overview Background Flowchart, GUI, Features

Feb.21,2003 Xiaoyan Song 3

Motivation

Present a handy tool for color calculation A tool for color science short-course

education

Feb.21,2003 Xiaoyan Song 4

Project Overview

CIE Standard Demo • Illuminants A and D65

• Observer (1931 and 1964)

Color Matching Function Color Spaces Transformation Color Difference Calculation

Feb.21,2003 Xiaoyan Song 5

Background

CIE • Commission Internationale DE ’ECLARAGE• International Commission on Illumination

CIE Standard (Illuminants, Observer) Tristimulus Calculation Color Space Color Difference

Feb.21,2003 Xiaoyan Song 6

Standard Illuminant Light defined by a relative

spectral power distributionCI E Standard I l l umi nant:F

0

10

20

30

40

50

380 480 580 680 780Wavel ength(nm)

Rela

tive

Pow

er

F1F2F3F4

CI E Standard I l l umi nants

0

50

100

150

200

250

300

380 480 580 680 780

Wavel ength(nm)

Rela

tive

Pow

er

AD65

Feb.21,2003 Xiaoyan Song 7

Standard ObserverCI E Standard Observer

- 0. 5

0

0. 5

1

1. 5

2

2. 5

360 460 560 660 760

Wavel ength

Tri

stim

ulus

Val

ues

x2y2z2x10y10z10

Feb.21,2003 Xiaoyan Song 8

Calculating Tristimulus

Feb.21,2003 Xiaoyan Song 9

Color Space

It is used for color specification

XYZ

Chromaticity

1976 L*a*b*

Feb.21,2003 Xiaoyan Song 10

Color Difference

Delta E*abDelta E*ab

Delta E*94Delta E*94

Delta E*00Delta E*00

Feb.21,2003 Xiaoyan Song 11

Feb.21,2003 Xiaoyan Song 12

Flowchart

Color CalculatorColor Calculator

DatabaseDatabase

Color CalculatorColor Calculator

User’s Input DataUser’s Input Data

Calculation ResultCalculation Result Graphic OutputGraphic Output

Feb.21,2003 Xiaoyan Song 13

GUI

Feb.21,2003 Xiaoyan Song 14

Features I:

Flexible Options for CMF• Illuminant A OR Illuminant D65• 2 Degree OR 10 Degree Observer• Wavelength ranges and interval• Calculation Methods

• CIE traditional method

• ASTM 308

• Luminance Unit

Feb.21,2003 Xiaoyan Song 15

Feature II:

Introduce new improvements in Color Difference Calculation• CIELAB• CIE94• CIE2000 (new)

Feb.21,2003 Xiaoyan Song 16

Feature III: Visualization

Visualization• Standard Observer• Standard Illuminant • Reflectance

Flexible results output• Data .txt file• Various image file (jpg,bmp,png,gif,tiff,…)

Feb.21,2003 Xiaoyan Song 17

Future Work

Computer platforms compatibility

Feb.21,2003 Xiaoyan Song 18

Thanks !