Are all Color Conversion Engines PCS compliant?

.../ testing in progress

How to identify if a color space is Perfect Color Space compliant?

A) Comprehensive Test Chart

256-Level Test Pattern

B)  Quick Test Chart

1. Read the Quick test chart with Photoshop CS.
2. Assign profole for the image to ProPhoto RGB.
3. Convert to the destination space whose profile is to be tested.
4. Use the INFO display in CS to examine the converted primary color and gray scale values.
5.  Repeat above procedure with profile for the image assigned to Adobe RGB.

What is Perfect Color Space?

(Preliminary)

 
The Concept of PcS
A perfect RGB color space is one that possesses both of the following basic characteristics, under D50 illuminant and 2° observer conditions and when color space conversion is carried out with relative colorimetric rendering intent.

1. RGB Scalability
    The 3 primary colors (R, G and B)  would remain homogenous (*) when color space conversion is carried out within the Perfect Color Space family.
   
2.  Neutrality Consideration
     R=G=B,  or equal amount of R,G and B will yield perfect neutral gray. It is proposed that the RGB values for  any 2 of the primaries along the neutral axis must be identical and that the third primary should not be deviated from this value by more than 1 count after conversion. This specification was made after careful studying of the currently available color spaces. Refer to below note for examples.

In view of the above requirement, not all the currently known color spaces are Perfect Color Space compliant.

The following list is by no means exhaustive.
The color spaces in RED are Perfect Color Space compliant.

                                 Perfect Color Space/

Color Space      Gamut Volume   No. of Imaginary Primary

1.  ExtremeRGB     2,826,506            No / 3

2.  DCam5          2,755,025            No / 3 

3.  MaxRGB         2,529,960            No / 3

4.  DCam4          2,439,139            No / 2

5.  ProPhoto RGB   2,429,670            Yes/ 2

    MelissaRGB     2,428,701            Yes/ 2

6.  WideGamut RGB  1,994,225            No / 0

7.  jcSPACE RGB    1,971,923            Yes/ 0 (preliminary)

8.  BestRGB        1,960,820            No / 0

9.  DCam3          1,838,572            Yes/ 1

10. DonRGB4        1,738,253            No / 0

11. CEIRGB         1,712,629            No / 0
12. BetaRGB        1,655,272            No / 0

13. EktaSpace PS5  1,555,220            No / 1

14. Dcam2          1,431,681            No / 1

15. NTSC (1953)    1,383,526            No / 0
16. eciRGB_v2      1,285,904            No / 0

17. NTSC (1953)    1,257,099            No / 0          

18. AdobeRGB(1998) 1,165,420            Yes/ 0

19. BruceRGB       950,900              Yes/ 0

20. Generic RGB    849,794              No / 0
21. PAL/SECAM      813,794              No / 0

22. sRGB           798,455              Yes/ 0

23. ColorMatch RGB 790,723              Yes/ 0          

24. AppleRGB       763,273              Yes/ 0

25. SMPTE-C        725,385              No / 0

26. DCam1          712,145              No / 0

Note: Examples of acceptable neutral gray after conversion
a) Perfect neutral,  RGB=(135 135 135)
b) Acceptable neutral gray after conversion, RGB= (135 136 135)
c) Unacceptable neutral gray after conversion, RGB= (134 135 136) or (135 135 137)

Test Condition
Color conversion with Relative Colorimetric rendering intent is specified  and that is due to White reference for the profiles may not be exactly Lab=(100.000, 0.000, 0.000).


.../ to be continued