[ASLO] webcam images and control

[Emmanuel Di Folco]

Dear all,
I am developing pedagogical activities using the integrated webcam of  
the XO laptop.
My project aims at taking images of the Moon, by fixing a small scope  
in front of the webcam.
I am now facing the following problems:
- images are saturated because there is an automatic adjustment of  
the gain (or of the camera integration time ?)
- images are compressed (JPG) and hence of very poor quality

I am using the "Record" activity to make the images.

I would like to be able to :
- control the gain or integration time of the camera (mode Photo, not  
video) in order not to saturate (this is obviously feasible, since  
the images taken during the day are not saturated !)
- eventually restrict the size of the screen window that is  
considered by the 'automatic gain adjustment algorithm' (where I  
would insert the moon)
- gather the raw images, not the JPG compressed ones.

Could any one help me ?
Thanks in advance & best regards,
E. Di Folco
CEA + La Main a la pate (France)