maybe read this:

http://processing.org/reference/get_.html

get() (as a stand alone command) can give you

a rect from the screen or one single pixel data

it can give you (as a method of the object PImage) the same for this image:

http://processing.org/reference/PImage.html
http://processing.org/reference/PImage_get_.html


in theory you could use threads as well later...

see also

http://processing.org/reference/

Hello  Chrisir,

maybe you can look in the examples
e.g.
http://processing.org/learning/topics/pixelarray.html
http://processing.org/learning/topics/histogram.html

from here
http://processing.org/learning/topics/

what exactly do you want to do?

You can e.g. for loop over an given image and give its tiles (rects) to a function.
This function could calculate the average red value for each tile (adding up all pixels red values in the tile and dividing it by their number)

the for loop

1. for x......
2. for y......
3.     imageAnalyse(img.get( x*10, y*10 );
4. }
5. }

or so....