[PD] Video Processing

Mathieu Bouchard matju at artengine.ca
Wed Jun 16 03:59:40 CEST 2010

On Mon, 14 Jun 2010, Sean Harrigan wrote:

> yes, it is R-G and G-B and then i look at a ratio between those 2 
> values.  Thanks for the idea of using pix_colormatrix.  As for the 
> efficency, i am looking to, in the end, to be able to take a streaming 
> video of approx.  1280*960 and apply this filter/algorthim and hopefully 
> produce a picture in the range of 5-10 Frames per second.  Do you think 
> that is possible with this program? or should I be using another 
> program.  Thank you for your time   ~Sean

12 million pixels per second is very doable, but it depends on your 
computer. You have to try it. A step I missed is the division. I don't 
know how to do that in GEM, but I know how to do it in GridFlow and I can 
get more than 12 million pixels per second for that on my old computer. 
With a lookup table it gets even faster.

How do you expect to handle the sign of (R-G)/(G-B) ?
I'm wondering what this ratio might mean to you...

> the result is going to be a streaming video in that has certain objects 
> that fall into a range for RGB values that are going to be highlighted 
> and the remaning values are going to be in grayscale.

If you are just going to threshold the result of the division in an 
interval, it may be possible to rework the formula to not use any 

e.g. (R-G)/(G-B)<1 is the same as (R-G)<(G-B) or (R+B)<(G+G).

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| Mathieu Bouchard, Montréal, Québec. téléphone: +1.514.383.3801

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