[PD] mean color value of a video grid

[vincent rioux]

Dear list,
I am searching for a solution to this problem :
- given that a video stream - grey scale - is divided in say 8 
rectangles-zones constituting a grid.
- compute a time-varying mean value (over space) of the degree of 
illumination (or shading) of each zone.

i am right now thinking of a combination of :

pix_video (to read a stream from a webcam e.g.)
8 pix_crop (to divide the image)
pix_snap to take a snapshot as a picture.
pix_mean_color to compute the mean value.

This should work but i am may be missing some more direct way of doing 
this...
Moreover would it be possible to compute these values on a more complex 
shape than a rectangle?

as one can see, i will probably use Gem as it's the easiest to run and 
install on osx but i wonder if it won't be easier or more 
straightforward to code with gridflow or pdp?


vincent