Perhaps some variation of
SetTextContrastColor <- function(color)
{
ifelse( mean(col2rgb(color)) > 127, "black", "white")
}
Mark Heckmann wrote:
To the R color experts:
I need to detect if a chosen background color (as hex e.g. #910322) is
light or dark.
If it is dark I need to ovelay it with light text and vice versa.
Thus I would like to implement the following pseudo code:
if (brightness(color) > somevalue) textcolor= dark else textcolor=red
I am not too familiar with color systems. My idea was to convert the
hex value to hsv / hsl space and extract the v or l value.
1) I am not sure if this is the way to go.
2) I do not succeed in it. convertColor {grDevices} or make.rgb
{grDevices} did not help me with that. How can I convert hex to hsv/
hsl space
How would you detect the (perceived) color brightness?
Thanks
Mark
–––––––––––––––––––––––––––––––––––––––
Mark Heckmann
Dipl. Wirt.-Ing. cand. Psych.
Vorstraße 93 B01
28359 Bremen
Blog: www.markheckmann.de
R-Blog: http://ryouready.wordpress.com
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Professor, Psychology Dept.
York University Voice: 416 736-5115 x66249 Fax: 416 736-5814
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