I guess I'm playing devil's advocate, but if you were testing for "blue"-ness, wouldn't you convert to HSV and compare the H, regardless of S or V?
gc On Fri, Jul 1, 2011 at 4:52 AM, Mark Schonewille < m.schonewi...@economy-x-talk.com> wrote: > Tiemo, > > The distance between any colour (1) and a colour chosen by you (2; e.g. > r=0, g=0, b=255) can be calculated as > > sqrt((r1-r2)^2+(g1-g2)^2+(b1-b2)^2) <= T > > where T is a threshold between 0 and 442 set by you. Change the colour of > the background pixel whenever the distance between the colour of that pixel > and your selected colour is less than the threshold. > > I use this technique in Color Converter http://www.color-converter.com > > -- > Best regards, > > Mark Schonewille > > Economy-x-Talk Consulting and Software Engineering > Homepage: http://economy-x-talk.com > Twitter: http://twitter.com/xtalkprogrammer > KvK: 50277553 > > New: Download the Installer Maker Plugin 1.6 for LiveCode here > http://qery.us/ce > > On 1 jul 2011, at 11:39, Tiemo Hollmann TB wrote: > > > Hello, > > > > I am taking the mousecolor at different points from an image by script > (not > > by clicking). I would like to analyse if the color I've taken is a "kind > of > > blue", or another color. I want to change the backgroundcolor of an > image. > > The background is always blue, but different blues and changing over the > > background. So what I want to do is to verify, what is background and > what > > is foreground of my image. > > > > 100% pure blue would be 0,0,255. But for a human being 25,75,130 > (greyblue) > > is also still blue, but 240,20,180 is pink, though the third RGB value is > > higher as in my greyblue. > > > > So I can't just check only the third RGB value, neither the sum or cross > > total. Has anybody ever heard, if you can define at all by math "what is > > blue"? > > > > Any color specialist around here? > > > > Tiemo > > > > _______________________________________________ > use-livecode mailing list > use-livecode@lists.runrev.com > Please visit this url to subscribe, unsubscribe and manage your > subscription preferences: > http://lists.runrev.com/mailman/listinfo/use-livecode > _______________________________________________ use-livecode mailing list use-livecode@lists.runrev.com Please visit this url to subscribe, unsubscribe and manage your subscription preferences: http://lists.runrev.com/mailman/listinfo/use-livecode
