1. Principles of Color Technology Chapter 6 Producing Colors BOYS. BERNS Principles of Color Technology Chapter 6 Producing Colors BOYS. BERNS Speaker:Yi-Ling Chen ( 陳宜伶 ) Advisor: Prof. Han-Ping D. Shieh ( 謝漢萍教授 ) Prof. Yi-Pai Huang ( 黃乙白教授 ) Institute of Electro-Optical Engineering, National Chiao Tung University, Hsinchu, Taiwan June 26 th 2008

2. 2 Advanced Display Optics Lab Y. L. Chen Outline  Color modeling  Color mixing laws -Theoretical additive primaries -Theoretical subtractive primaries  Additive mixing  Subtractive mixing  Conclusions

3. 3 Advanced Display Optics Lab Y. L. Chen Outline  Color modeling  Color mixing laws -Theoretical additive primaries -Theoretical subtractive primaries  Additive mixing  Subtractive mixing  Conclusions

4. 4 Advanced Display Optics Lab Y. L. Chen Color Modeling Input Output Color Modeling Statistical techniques are used to develop a mathematical formula in describing color. Mathematical relationship

5. 5 Advanced Display Optics Lab Y. L. Chen Outline  Color modeling  Color mixing laws -Theoretical additive primaries -Theoretical subtractive primaries  Additive mixing  Subtractive mixing  Conclusions

6. 6 Advanced Display Optics Lab Y. L. Chen Color Mixing Laws Trichromatic theory - Additive versus subtractive mixing Opponent-colors theory RGBCYM S M L Color modeling is established according to trichromatic theory.

7. 7 Advanced Display Optics Lab Y. L. Chen Additive Mixing Laws Theoretical Additive Primaries 500 600

8. 8 Advanced Display Optics Lab Y. L. Chen Theoretical Additive Primaries

9. 9 Advanced Display Optics Lab Y. L. Chen It’s more easily understood how visual system converts light to color. Theoretical Subtractive Primaries

10. 10 Advanced Display Optics Lab Y. L. Chen Outline  Color modeling  Color mixing laws -Theoretical additive primaries -Theoretical subtractive primaries  Additive mixing  Subtractive mixing  Conclusions

11. 11 Advanced Display Optics Lab Y. L. Chen The relationship between the color components and spectral data is linear. (1) Scalability Additive Mixing (i)

12. 12 Advanced Display Optics Lab Y. L. Chen (2) Additivity The opto-electronic transfer function (OETF) is nonlinear. Linear mixing law results Additive Mixing (ii) An accurate color modeling consists of linear matrix and nonlinear transfer function.

13. 13 Advanced Display Optics Lab Y. L. Chen Subtractive Mixing Subtractive mixing consists of absorption and scattering. Simple-subtractive mixing only involves absorption. The material includes colored filters (glass, gelatin, plastic) and colored liquids.

14. 14 Advanced Display Optics Lab Y. L. Chen Simple-Subtractive Mixing Laws Bouguer-Beer Law Bouguer and Lambert Beer

15. 15 Advanced Display Optics Lab Y. L. Chen Scalability & additivity Simple-Subtractive Mixing Laws (ii) Simple-subtractive mixing also obeys scalability and additivity.

16. 16 Advanced Display Optics Lab Y. L. Chen Flowchart of Color Prediction Select thickness Account difference between theoretical and effective thickness Apply mixing model Convert from absorbance to internal transmittance Convert to measured transmittance Calculate tristimulus values XYZ Calculate CIELAB values Final L* a* b*

17. 17 Advanced Display Optics Lab Y. L. Chen Outline  Color modeling  Color mixing laws -Theoretical additive primaries -Theoretical subtractive primaries  Additive mixing  Subtractive mixing  Conclusions

18. 18 Advanced Display Optics Lab Y. L. Chen Conclusions Color models relate the input to a coloration system with colorimetric values. To establish appropriate color models, we should recognize color mixing laws (additive/subtractive). Color model consists of linear matrix and nolninear OETF.

19. 19 Advanced Display Optics Lab Y. L. Chen

20. 20 Advanced Display Optics Lab Y. L. Chen