[PD] Isolating RGB colours in GEM

[Jaime Oliver]

I made this object a while ago to track red and blue, but it can be extended
to track other pure colors:

http://www.jaimeoliver.pe/archives/645

best,

J

On Sun, May 23, 2010 at 1:00 PM, Mathieu Bouchard <matju at artengine.ca>wrote:

> On Sat, 22 May 2010, Ryan Trigg wrote:
>
>  I am currently trying to find a way to isolate a colour in a live video
>> stream.  For example, if I chose red, any object in the video that does not
>> contain red (above a certain threshold) would be black.  Does such an object
>> exist in GEM?  Thanks for your help.
>>
>
> [pix_colormatrix] is very good for that stuff. Optionally you can combine
> it with [pix_threshold] or others.
>
> [pix_colormatrix] allows you, for example, to do things like new_red =
> old_red - old_green - old_blue, in order to identify redness in a way that
> excludes yellow, purple and white. You'd make a column with constants 1, -1,
> -1.
>
> For singling out other colors you would use those numbers in a different
> order, or the numbers 1, 1, -2 in any order (for secondary colors), or any
> other combination (for finding other colors).
>
>  _ _ __ ___ _____ ________ _____________ _____________________ ...
> | Mathieu Bouchard, Montréal, Québec. téléphone: +1.514.383.3801
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-- 
Jaime E Oliver LR

www.jaimeoliver.pe

858 750 0924 (cel)
858 202 1522 (home)
9168 Regents Rd. Apt. G
La Jolla, CA 92037
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