GSoC: automatic brightness adjustment

[Sebastian Kügler]

On Thursday, April 05, 2012 00:32:19 Mike Dean wrote:
> As an electrical engineer, I find this idea sound.  With a low sampling
> rate, such as 0.5 Hz (once every 2 seconds), the additional power draw
> should be negligible.  1/60th Hz is far too slow to produce enough quality
> for users to appreciate it.  0.5 Hz should be considered a minimum.  While
> the computer is plugged in, an effective sampling rate of 5 Hz or better
> would provide very nice quality.  In hardware, we low pass filter the
> output from the sensor to stabilize the display brightness.  In software,
> you would do this by averaging the samples.
> 
> Incidentally, this is a feature I've wished would make it into Linux
> desktops for quite some time now.

Powering up and down the webcam takes time and energy. My webcam here, takes 
about 5 - 10 seconds to start up, that makes a sampling rate of 2s just not 
work. 

On the other hand, ambient light sensors adjusting screen brightness are 
really only useful if they're quick to react. Imagine yourself late at night 
in the dark, grabbing the laptop, screen pops on and blinds you. You surely 
don't want to wait until it self-adjusts...

I agree with Dario that webcams are not really suitable for this kind of 
thing.
-- 
sebas

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