SATURATION32: Difference between revisions

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{{PageDescription}}
{{PageDescription}}
* The value returned is of type [[DOUBLE]] in the range 0 to 100 percent, use [[CINT]] to work with integers only.
* The value returned is of type [[DOUBLE]] in the range 0 to 100 percent.
** 100% is the richest color possible, as closer the value comes to 0%, as more faded is the color, ending at dull gray.
** 100% is the richest color possible, as closer the value comes to 0% as more faded is the color, ending at dull gray.
** The intensity of the gray (i.e. black >> darkgray >> midgray >> lightgray >> white) depends on the brightness value.
** The intensity of the gray (i.e. black >> darkgray >> midgray >> lightgray >> white) depends on the brightness value.
;Naming differences
;Naming differences
Line 20: Line 20:
:* However, this function is not suitable for the HSL (L=Lightness) colorspace, which is widely used in the Web/CSS.
:* However, this function is not suitable for the HSL (L=Lightness) colorspace, which is widely used in the Web/CSS.
;Precision drawbacks
;Precision drawbacks
:* When converting between colorspaces, rounding errors can occur. While the HSB colorspace has virtually infinite precision only limited by the used floating point type, RGB is represented in 8-bit integers (0-255) only, which can lead to quantization errors. In fact, not all colors in HSB can be accurately represented in RGB and vice versa.
:* When converting between colorspaces, rounding errors can occur.
:* However, if you limit yourself to only passing integer values to [[_HSB32]] or [[_HSBA32]], just as you do for the respective RGB colorspace functions [[_RGB32]] or [[_RGBA32]], then you can get back that exact values by [[CINT]]ing the results returned by [[_HUE32]], [[_SATURATION32]] and [[_BRIGHTNESS32]].
:* While the HSB colorspace has virtually infinite precision using floating point values, RGB is limited to 8-bit integers (0-255) only, which can lead to quantization errors.
:* In fact, not all colors in HSB can be accurately represented in RGB, but the opposite is possible.
:* It can be guaranteed, that the [[_HUE32]], [[_SATURATION32]] and [[_BRIGHTNESS32]] values retrieved from any arbitrary RGB color will reproduce the exact same RGB color when passed back through [[_HSB32]].




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{{PageExamples}}
{{PageExamples}}
;Example 1: Showcasing the HSB value retrieving functions and demonstrate the quantization errors.
{{CodeStart}}
{{CodeStart}}
{{Cl|PRINT}} {{Text|<nowiki>"Creating a color using the HSB colorspace..."</nowiki>|#FFB100}}
{{Cl|PRINT}} {{Text|<nowiki>"Creating a color using the HSB colorspace..."</nowiki>|#FFB100}}
c~& = {{Cl|_HSB32}}({{Text|90|#F580B1}}, {{Text|75|#F580B1}}, {{Text|65|#F580B1}})
cOrig~& = {{Cl|_HSB32}}({{Text|90|#F580B1}}, {{Text|75|#F580B1}}, {{Text|65|#F580B1}})
 
{{Cl|PRINT}} {{Text|<nowiki>"_HSB32( 90, 75, 65 ) = _RGB32("</nowiki>|#FFB100}}; {{Cl|_RED32}}(cOrig~&); {{Text|<nowiki>","</nowiki>|#FFB100}}; {{Cl|_GREEN32}}(cOrig~&); {{Text|<nowiki>","</nowiki>|#FFB100}}; {{Cl|_BLUE32}}(cOrig~&); {{Text|<nowiki>")"</nowiki>|#FFB100}}
{{Cl|PRINT}} {{Text|<nowiki>"_HSB32( 90, 75, 65 ) = _RGB32("</nowiki>|#FFB100}}; {{Cl|_RED32}}(c~&); {{Text|<nowiki>","</nowiki>|#FFB100}}; {{Cl|_GREEN32}}(c~&); {{Text|<nowiki>","</nowiki>|#FFB100}}; {{Cl|_BLUE32}}(c~&); {{Text|<nowiki>")"</nowiki>|#FFB100}}
{{Cl|PRINT}}
{{Cl|PRINT}} {{Text|<nowiki>"Back to HSB values (notice the quantization errors)."</nowiki>|#FFB100}}
{{Cl|PRINT}} {{Text|<nowiki>"The HSB color was not accurately representable in RGB."</nowiki>|#FFB100}}
{{Cl|PRINT}} {{Text|<nowiki>"Hue.......:"</nowiki>|#FFB100}}; {{Cl|_HUE32}}(cOrig~&)
{{Cl|PRINT}} {{Text|<nowiki>"Saturation:"</nowiki>|#FFB100}}; {{Cl|_SATURATION32}}(cOrig~&)
{{Cl|PRINT}} {{Text|<nowiki>"Brightness:"</nowiki>|#FFB100}}; {{Cl|_BRIGHTNESS32}}(cOrig~&)
{{Cl|PRINT}}
{{Cl|PRINT}}
{{Cl|PRINT}} {{Text|<nowiki>"back to HSB values (notice the precision loss)..."</nowiki>|#FFB100}}
cBack~& = {{Cl|_HSB32}}({{Cl|_HUE32}}(cOrig~&), {{Cl|_SATURATION32}}(cOrig~&), {{Cl|_BRIGHTNESS32}}(cOrig~&))
{{Cl|PRINT}} {{Text|<nowiki>"Hue.......:"</nowiki>|#FFB100}}; {{Cl|_HUE32}}(c~&)
{{Cl|PRINT}} {{Text|<nowiki>"However, when using the retrieved HSB values again for conversion,"</nowiki>|#FFB100}}
{{Cl|PRINT}} {{Text|<nowiki>"Saturation:"</nowiki>|#FFB100}}; {{Cl|_SATURATION32}}(c~&)
{{Cl|PRINT}} {{Text|<nowiki>"then we definitly get back the exact same RGB color again."</nowiki>|#FFB100}}
{{Cl|PRINT}} {{Text|<nowiki>"Brightness:"</nowiki>|#FFB100}}; {{Cl|_BRIGHTNESS32}}(c~&)
{{Cl|PRINT}} {{Text|<nowiki>"Red.......:"</nowiki>|#FFB100}}; {{Cl|_RED32}}(cBack~&)
{{Cl|PRINT}} {{Text|<nowiki>"Green.....:"</nowiki>|#FFB100}}; {{Cl|_GREEN32}}(cBack~&)
{{Cl|PRINT}} {{Text|<nowiki>"Blue......:"</nowiki>|#FFB100}}; {{Cl|_BLUE32}}(cBack~&)
{{Cl|PRINT}}
{{Cl|PRINT}}
{{Cl|PRINT}} {{Text|<nowiki>"but with CINT() we can get back the original values..."</nowiki>|#FFB100}}
{{Cl|PRINT}} {{Text|<nowiki>"Conclusion:"</nowiki>|#FFB100}}
{{Cl|PRINT}} {{Text|<nowiki>"Hue.......:"</nowiki>|#FFB100}}; {{Cl|CINT}}({{Cl|_HUE32}}(c~&))
{{Cl|PRINT}} {{Text|<nowiki>"Not every HSB color can be accurately represented in 8-bit integer RGB,"</nowiki>|#FFB100}}
{{Cl|PRINT}} {{Text|<nowiki>"Saturation:"</nowiki>|#FFB100}}; {{Cl|CINT}}({{Cl|_SATURATION32}}(c~&))
{{Cl|PRINT}} {{Text|<nowiki>"but every RGB color can be accurately represented in floating point HSB."</nowiki>|#FFB100}}
{{Cl|PRINT}} {{Text|<nowiki>"Brightness:"</nowiki>|#FFB100}}; {{Cl|CINT}}({{Cl|_BRIGHTNESS32}}(c~&))
 
{{Cl|END}}
{{Cl|END}}
{{CodeEnd}}
{{CodeEnd}}

Latest revision as of 19:47, 30 January 2025

The _SATURATION32 function returns the saturation value (HSB colorspace) of a given 32-bit ARGB color.


Syntax

saturation# = _SATURATION32(argbColor~&)


Parameters

  • argbColor~& is the 32-bit ARGB color value to retrieve the saturation value from.


Description

  • The value returned is of type DOUBLE in the range 0 to 100 percent.
    • 100% is the richest color possible, as closer the value comes to 0% as more faded is the color, ending at dull gray.
    • The intensity of the gray (i.e. black >> darkgray >> midgray >> lightgray >> white) depends on the brightness value.
Naming differences
  • The HSB (B=Brightness) colorspace is also known as HSV (V=Value) and sometimes even called HSI (I=Intensity), but that's all just different names for the same thing.
  • However, this function is not suitable for the HSL (L=Lightness) colorspace, which is widely used in the Web/CSS.
Precision drawbacks
  • When converting between colorspaces, rounding errors can occur.
  • While the HSB colorspace has virtually infinite precision using floating point values, RGB is limited to 8-bit integers (0-255) only, which can lead to quantization errors.
  • In fact, not all colors in HSB can be accurately represented in RGB, but the opposite is possible.
  • It can be guaranteed, that the _HUE32, _SATURATION32 and _BRIGHTNESS32 values retrieved from any arbitrary RGB color will reproduce the exact same RGB color when passed back through _HSB32.


Availability

  • none

    none

  • v4.0.0

    v4.0.0

  • Apix.png
  • yes

    yes

  • yes

    yes

  • yes

    yes


Examples

Example 1
Showcasing the HSB value retrieving functions and demonstrate the quantization errors.
PRINT "Creating a color using the HSB colorspace..."
cOrig~& = _HSB32(90, 75, 65)
PRINT "_HSB32( 90, 75, 65 ) = _RGB32("; _RED32(cOrig~&); ","; _GREEN32(cOrig~&); ","; _BLUE32(cOrig~&); ")"
PRINT
PRINT "Back to HSB values (notice the quantization errors)."
PRINT "The HSB color was not accurately representable in RGB."
PRINT "Hue.......:"; _HUE32(cOrig~&)
PRINT "Saturation:"; _SATURATION32(cOrig~&)
PRINT "Brightness:"; _BRIGHTNESS32(cOrig~&)
PRINT
cBack~& = _HSB32(_HUE32(cOrig~&), _SATURATION32(cOrig~&), _BRIGHTNESS32(cOrig~&))
PRINT "However, when using the retrieved HSB values again for conversion,"
PRINT "then we definitly get back the exact same RGB color again."
PRINT "Red.......:"; _RED32(cBack~&)
PRINT "Green.....:"; _GREEN32(cBack~&)
PRINT "Blue......:"; _BLUE32(cBack~&)
PRINT
PRINT "Conclusion:"
PRINT "Not every HSB color can be accurately represented in 8-bit integer RGB,"
PRINT "but every RGB color can be accurately represented in floating point HSB."
END


See also


Navigation:
Main Page with Articles and Tutorials
Keyword Reference - Alphabetical
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