1. A Colorimetric Analysis Methodology for Philatelic Studies
Prepared for Stampshow 2010
David L. Herendeen
12 August 2010

2. How Many Colors?
1,2 or 3
200,010,010
200,020,10
There are 2!

3. How Many Colors? 1,2 or 3 There are 3! 230,250,090 230,235,90
220,240,085
There are 3!

4. How Many Colors?
1,2 or 3
200,010,010
200,020,010
There are 2!

5. What Color Are These 1851 Stamps ?
Bright Orange Brown
Rose Brown
Intense Orange Brown
Dull Red
Dull Claret
Pale Orange Brown
Morocco
Dull Red
Rose Brown
Reddish Orange Brown
Deep Orange Brown
Dull Claret
Courtesy National Postal Museum

6. What Color Are These 1851 Stamps ?
Bright Orange Brown
Rose Brown
Intense Orange Brown
Dull Red
Dull Claret
Pale Orange Brown
Morocco
Dull Red
Rose Brown
Reddish Orange Brown
Deep Orange Brown
Dull Claret
Courtesy National Postal Museum

7. Color is not so Easy IS IT ??
Is there Another Way?

8. Talking Points Some background What we planned What we did
What we learned
What’s next?
NPM Support ...A Retrospective

9. Background What is color? What is colorimetry
Spectroscopy and the VSC 6000
How are colors measured?
Commission International de l’Eclairage (CIE)

10. Background
CIE Color Models
Measure
Reflectance or
Absorption of Light

11. What we planned Use the NPM VSC 6000 to perform colorimetric analysis
Understand colorimetry in the philatelic context
Understand the scientific measurement of color and its relationship to stamps
Determine if scanning can be used as a cost-effective substitute for spectroscopy

12. What we did
Analyzed hundreds of Slovenian postage due stamps of
Recorded results and reduced data
Correlated spectroscopic results with human color expert
Developed interpolation model for use with scanners

13. …What we did
Sampling the stamps

14. …What we did
Sampling the stamps

15. …What we did
Sampling the stamps

16. Processing the results
…What we did
Processing the results

17. Processing the results
…What we did
Processing the results

18. …What we did
Comparison by expert

19. …What we did
Color categories

20. …What we did
Color categories

21. …What we did
Color categories
Brick Red

22. …What we did
Color categories
Deep brownish carmine
Brick Red

23. …What we did
Color categories
Deep brownish carmine
Brick Red
Red

24. Color categories …What we did Deep brownish carmine Brick Red Red

25. Categories are “Fuzzy”
…What we did
Categories are “Fuzzy”

26. Categories are “Fuzzy”
…What we did
Categories are “Fuzzy”
1.00
0.84
0.40
0.17
0.14
Fuzzy Weighting
Function

27. Theoretical development
…What we did
Theoretical development
Formulated a method for defining color categories
Created a model for understanding how individual perception can affect philatelic color identification
Correlated this model to “real” test data
Formed a building block for future philatelic color research

28. 3D Interpolation Function
…What we did
Using a scanner
Spectroscope for Tristimulus Values (X,Y,Z)
Calibrate Your Scanner (R,G,B)
3D Interpolation Function
Maps to: (Xu,Yu,Zu)
u’,v’
Unknown Sample (Ru,Gu,Bu)

29. What we learned How to apply the VSC 6000 for colorimetry
Philatelic color is NOT a matching problem, it is about categorization
Colorimetry is faster and cheaper than x-ray spectroscopy methods
Scanners can be used to identify colors IF preliminary analysis has been performed

30. What’s next? Completing the scanner mapping
Documenting and publishing all results
Extending the methodology to new projects

31. Documenting the work Two papers:
…What’s next?
Documenting the work
Two papers:
Philatelic Shade Discrimination Based on Measured Color (Herendeen, Allen and Lera)
Color Research and Applications and/or London Philatelist
Using a Scanner to Determine Stamp Shades (Herendeen, Allen and Lera)
London Philatelist or Collectors Club Philatelist

32. NPM Support Value of NPM scholarship program
Leveraging human resources
Incubator for IAP

33. Acknowledgements Mr. Allen Kane
For his vision of extending the services of the NPM to the philatelic world
Mr. Thomas Lera, Winton Blount Chair of Research, NPM
For his continual support and assistance with all aspects of this effort
Mr. James Allen, Senior Fellow, IAP
For his long hours sorting and categorizing Slovenian postage dues

34. The End