HUE32: Difference between revisions
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* The value returned is of type [[DOUBLE]] in the range 0 to 360 degrees | * The value returned is of type [[DOUBLE]] in the range 0 to 360 degrees. | ||
** The color wheel starts with red(0), turns to yellow(60), green(120), cyan(180), blue(240), magenta(300) to red(360) again. | ** The color wheel starts with red(0), turns to yellow(60), green(120), cyan(180), blue(240), magenta(300) to red(360) again. | ||
** Mixed colors are represented by values between those 6 base color angles. | ** Mixed colors are represented by values between those 6 base color angles. | ||
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{{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}} | ||
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}}( | {{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>" | cBack~& = {{Cl|_HSB32}}({{Cl|_HUE32}}(cOrig~&), {{Cl|_SATURATION32}}(cOrig~&), {{Cl|_BRIGHTNESS32}}(cOrig~&)) | ||
{{Cl|PRINT}} {{Text|<nowiki>" | {{Cl|PRINT}} {{Text|<nowiki>"However, when using the retrieved HSB values again for conversion,"</nowiki>|#FFB100}} | ||
{{Cl|PRINT}} {{Text|<nowiki>" | {{Cl|PRINT}} {{Text|<nowiki>"then we definitly get back the exact same RGB color again."</nowiki>|#FFB100}} | ||
{{Cl|PRINT}} {{Text|<nowiki>" | {{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>" | {{Cl|PRINT}} {{Text|<nowiki>"Conclusion:"</nowiki>|#FFB100}} | ||
{{Cl|PRINT}} {{Text|<nowiki>"Not every HSB color can be accurately represented in 8-bit integer RGB,"</nowiki>|#FFB100}} | |||
{{Cl|PRINT}} {{Text|<nowiki>" | {{Cl|PRINT}} {{Text|<nowiki>"but every RGB color can be accurately represented in floating point HSB."</nowiki>|#FFB100}} | ||
{{Cl|PRINT}} {{Text|<nowiki>" | |||
{{Cl|END}} | {{Cl|END}} | ||
{{CodeEnd}} | {{CodeEnd}} | ||
Revision as of 19:40, 30 January 2025
The _HUE32 function returns the hue value (HSB colorspace) of a given 32-bit ARGB color.
Syntax
- hue# = _HUE32(argbColor~&)
Parameters
- argbColor~& is the 32-bit ARGB color value to retrieve the hue value from.
Description
- The value returned is of type DOUBLE in the range 0 to 360 degrees.
- The color wheel starts with red(0), turns to yellow(60), green(120), cyan(180), blue(240), magenta(300) to red(360) again.
- Mixed colors are represented by values between those 6 base color angles.
- 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
v4.0.0
yes
yes
yes
Examples
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