I suspect you already know this, so I am wondering if your method actually works quite well as a first approximation.
It's been a few years since when I researched color spaces and I haven't done anything with them since, so I could well be wrong. I guess it would work as a very simple test to see if two colors are approximately similar, but I also like that idea with the cube you wrote about. It sounds like it is still RGB. So, the distance in the cube could be calculated as: var dist = Math.sqrt( Math.pow( red1 - red2, 2 ) + Math.pow( green1 - green2, 2 ) + Math.pow( blue1 - blue2, 2 ) ); Sorry, must run -- a friend is waiting in the car downstairs... Maybe I'll look into it later, colors are interesting. Last time, I couldn't find a transformation from various colorspaces to CIE XYZ, back and forth. Does anybody have some links? Mark On 10/31/06, John McCormack <[EMAIL PROTECTED]> wrote:
Mark, That's a facinating article in wikipedia but I don't know if I can ever understand it. One will try! In a book called Bitmapped Graphics Programming in C++ by Luse, there is a colour cube model which is helpful. The colour differences you calculate below are complicated by the question "If I minimize one colour component, could I not get closer by minimizing another?". In that model each colour is a linear distance along an axis, making a colour cube in 3d space. Grey (colours 128,128,128 or hex 0x7f7f7f) is in the centre. They grey line runs diagonally out from the origin, getting lighter as you move out. Choose a colour in that cube and the clossness of any other available colour can be found by using your distances, squaring them and finding out which one is the least 3d distance from the desired point. I suspect you already know this, so I am wondering if your method actually works quite well as a first approximation. John ----- Original Message ----- From: "Mark Winterhalder" <[EMAIL PROTECTED]> To: "Flashcoders mailing list" <flashcoders@chattyfig.figleaf.com> Sent: Monday, October 30, 2006 11:35 PM Subject: Re: [Flashcoders] Comparing HEX > > What would be the best way to loop the array and find the best match to > > myColor? > > A simple way would be do add up the difference to the red, green and > blue values. > You get the value for the channels like this: > > var red = color >> 16 & 0xff; > var green = color >> 8 & 0xff; > var blue = color & 0xff; > > Then you can do a Math.abs( red1 - red2 ) + Math.abs( green1 - green2 > ) + Math.abs( blue1 - blue2 ) and you get the total difference between > two colors. > > This isn't the most exact way to measure the distance between two > colors as perceived by an average human being, but if you want to > really know that perceived distance, then RGB isn't the right color > space and it gets a bit more complicated: > <http://en.wikipedia.org/wiki/Lab_color_space> > > HTH, > Mark > > > > On 10/31/06, Aaron Buchanan <[EMAIL PROTECTED]> wrote: > > Hello all! > > > > I am looking for a reference to read up on comparing two or more color > > values. I have not done a whole lot of work with color math so any > > foundation articles would be great. > > > > What I am trying to accomplish, say I have a var "myColor" which represents > > the color I would like to find the closest match for, I also have an array > > of other colors that are all shades of yellow: > > > > -- > > > > var myColor:Number = 0xffcc00 > > var similarColors:Array = [ 0xfce427, 0xdcb30a, 0xa48611]; > > > > -- > > > > What would be the best way to loop the array and find the best match to > > myColor? > > > > Thanks in Advance! > > > > -- > > Aaron Buchanan | Flash Developer, Lab-Media | T 909 702 1368 > > > > > > _______________________________________________ > > Flashcoders@chattyfig.figleaf.com > > To change your subscription options or search the archive: > > http://chattyfig.figleaf.com/mailman/listinfo/flashcoders > > > > Brought to you by Fig Leaf Software > > Premier Authorized Adobe Consulting and Training > > http://www.figleaf.com > > http://training.figleaf.com > > > _______________________________________________ > Flashcoders@chattyfig.figleaf.com > To change your subscription options or search the archive: > http://chattyfig.figleaf.com/mailman/listinfo/flashcoders > > Brought to you by Fig Leaf Software > Premier Authorized Adobe Consulting and Training > http://www.figleaf.com > http://training.figleaf.com > _______________________________________________ Flashcoders@chattyfig.figleaf.com To change your subscription options or search the archive: http://chattyfig.figleaf.com/mailman/listinfo/flashcoders Brought to you by Fig Leaf Software Premier Authorized Adobe Consulting and Training http://www.figleaf.com http://training.figleaf.com
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