Re: Determine brightness of colour/Convert to GrayLevel
- To: mathgroup at smc.vnet.net
- Subject: [mg89511] Re: Determine brightness of colour/Convert to GrayLevel
- From: Jens-Peer Kuska <kuska at informatik.uni-leipzig.de>
- Date: Wed, 11 Jun 2008 03:19:37 -0400 (EDT)
- Organization: Uni Leipzig
- References: <g2lno3$igu$1@smc.vnet.net>
- Reply-to: kuska at informatik.uni-leipzig.de
Hi, ?ToColor ToColor[color, form] converts color to form if form is GrayLevel, \ RGBColor or CMYKColor. Otherwise form[color] is evaluated and the \ result is expected to be a valid color directive. Regards Jens Szabolcs Horv=E1t wrote: > Colours have several representations, such as RGBColor, CMYKColor, > GrayLevel, etc. > > Is there a way to convert between these representations? More > specifically is there a way to convert a colour to GrayLevel? I would > like to determine the "brightness" of a colour to decide whether to > display text in black or in white on top of it. > > Also, is there a way to convert a colour to some canonical > representation? A workaround I found is Lighter[colour, 0], which > converts to RGBColor, but I was hoping that there exists a function > meant specifically for conversion (and not > blending/lightening/darkening). >