> Also, three items affect camera exposure: Aperture (or Iris for > those film industry conscious among you), Shutter speed, and gain. While > it's hard for me to envision a consumer end camera having Aperture control, > the camera I'm working on offers shutter speed and gain (I do have a high end > consumer camcorder that offers aperture control - but it uses firewire). V4L > offers no way to control these, therefore no way to set correct exposure. > I'm assuming that unlike my camera here, most cameras automatically set > exposure themselves. So, should I try cooking up my own automatic exposure > setting (again in the kernel driver), or should I write a utility which works > with the ioctl interface to set these parameters outside of V4L applications? The quickcam Express (qce-ga.sourceforge.net) doesn't have any useful reflection of the API settings (Hue, etc). But does have exposure control using gain and a electronic shutter. The approach taken with that driver is that the brightness is link to the average pixel value. You adjust the brightness down, and the driver attempts (over successive image grabs) to target a lower pixel value. The other controls are mapped on to something akin to colour balance. Regards, Matthew -- +---[ Matthew Tippett ]-[ Ph:+61 416 006 047 ]-[ Fax:+61 414 000 694 ]---+ +---[ TICons ]-[ mtippett@xxxxxxxxxxxxx ]-[ http://www.ticons.com.au/ ]--+ +---[ http://commercialos.org/ - Commercial Open Source Devel. Info ]---+
