Demo_Lib_Color_Space "Rabbit Hole"

[(X)]

Hi all,

Here is demonstration program based on a compilation of pseudo code functions designed to convert color from one color space to another.

I call it a Rabbit Hole because I rapidly felt like I was getting over my head. I think I see some light at the end of the tunnel.

Enjoy!

(X)

Of course this is a work in progress, but, it can be the basis of gaining much knowledge and mastery of color space and programming in general.

Worth noting is that I found a way to clone a UDT declared in the Library and use it in the main program as if the Library had exported it!

(See: Pointer variables in GFA help file and my other post on the subject: gb32.proboards.com/thread/393/export-udt-gl32-library-code)

[(X)]

Latest versions:

I worked out a bug that was not returning good RGB values from the HSL_to_RGB conversion.

It was a matter of working solely with Single type variables and converting multiplications or divisions on the spot with the Csng() function.

And, yes, I did get that little rush of Dopamine when I found the problem that had been plaguing me for almost a week.

N. B.: I am modifying the code quite a bit from day to day.  I will post the demo and library again, once it is more stable.

[(X)]

Here is the User Defined Type (UDT) I created for the color space library: Lib_Color_Space.G32

 '''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
 '
 ' Declare a global color space user defined type (UDT)
 ' variable that will ultimately guide the programmer
 ' through the available nomenclature.
 '
 Global CS As T_COLOR_SPACE
 Global Ptr_CS As Int32 = V:CS
 
 '
 ' Here are the COLOR SPACE user defined types...
 '
 Type T_COLOR_SPACE
   CIE       As T_CS_CIE
   CMYK      As T_CS_CMYK
   Hunter    As T_CS_HUNTER
   HSL       As T_CS_HSL
   HSV       As T_CS_HSV
   RGB       As T_CS_RGB
   Ref       As T_CS_REF
   Wht       As T_CS_WHT
   XYZ       As T_CS_XYZ
   YXZ       As T_CS_YXZ
 EndType
 
 Type T_CS_CIE
   -Single C, H, L, a, b, L1, a1, b1, L2, a2, b2, u, v
 EndType
 
 Type T_CS_CMYK
   -Single C, M, Y, K
 EndType
 
 Type T_CS_HUNTER
   -Single L, a, b
 EndType
 
 Type T_CS_HSL
   -Single H, S, L
 EndType
 
 Type T_CS_HSV
   -Single H, S, V
 EndType
 
 Type T_CS_REF
   -Single X, Y, Z, u, v
 EndType
 
 Type T_CS_RGB
   -Single R, G, B, aR, aG, aB
 EndType
 
 Type T_CS_WHT
   -Single L, C, H
 EndType
 
 Type T_CS_XYZ
   -Single X, Y, Z
 EndType
 
 Type T_CS_YXZ
   -Single X, Y, Z
 EndType
 
 '
 ' These reference values are taken from the provided TriStimulus Table.
 '
 With CS
   .Ref.X = 109.850!
   .Ref.Y = 100.000!
   .Ref.Z = 35.585!
 EndWith
 

 '
 ' (Tristimulus) Reference values of a perfect reflecting diffuser
 '
 ' Observer     2° (CIE 1931)           10° (CIE 1964)           Note
 ' Illuminant      X2      Y2      Z2      X10     Y10     Z10
 ' A            109.850 100.000  35.585 111.144 100.000  35.200  Incandescent/tungsten
 ' B             99.092 100.000  85.313  99.178 100.000  84.349  Old direct sunlight at noon
 ' C             98.074 100.000 118.232  97.285 100.000 116.145  Old daylight
 ' D50           96.422 100.000  82.521  96.720 100.000  81.427  ICC profile PCS
 ' D55           95.682 100.000  92.149  95.799 100.000  90.926  Mid-morning daylight
 ' D65           95.047 100.000 108.883  94.811 100.000 107.304  Daylight, sRGB, Adobe-RGB
 ' D75           94.972 100.000 122.638  94.416 100.000 120.641  North sky daylight
 ' E            100.000 100.000 100.000 100.000 100.000 100.000  Equal energy
 ' F1            92.834 100.000 103.665  94.791 100.000 103.191  Daylight Fluorescent
 ' F2            99.187 100.000  67.395 103.280 100.000  69.026  Cool fluorescent
 ' F3           103.754 100.000  49.861 108.968 100.000  51.965  White Fluorescent
 ' F4           109.147 100.000  38.813 114.961 100.000  40.963  Warm White Fluorescent
 ' F5            90.872 100.000  98.723  93.369 100.000  98.636  Daylight Fluorescent
 ' F6            97.309 100.000  60.191 102.148 100.000  62.074  Lite White Fluorescent
 ' F7            95.044 100.000 108.755  95.792 100.000 107.687  Daylight fluorescent, D65 simulator
 ' F8            96.413 100.000  82.333  97.115 100.000  81.135  Sylvania F40, D50! simulator
 ' F9           100.365 100.000  67.868 102.116 100.000  67.826  Cool White Fluorescent
 ' F10           96.174 100.000  81.712  99.001 100.000  83.134  Ultralume 50, Philips TL85
 ' F11          100.966 100.000  64.370 103.866 100.000  65.627  Ultralume 40, Philips TL84
 ' F12          108.046 100.000  39.228 111.428 100.000  40.353  Ultralume 30, Philips TL83
 '

[(X)]

I worked out a few error conditions to do with the Power operator: '^'.

This is the most up to date version of the library.

You 'll need to compile it etc etc...

Lib_Color_Space.G32 (45.7 KB)

Here is a demo that converts RGB to HSL and back again to RGB.

Notice that if you change the H, S or L value in mid conversion you will get a 'modified' RGB conversion, but, if you leave HSL alone then the original RGB is restored.

Demo Lib Color Space V3.G32 (767.69 KB)