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how to linearize light during a dayt whit abs_exposure camera parameter

asked 2016-10-03 06:35:10 -0500

gfx gravatar image

Hi,

On my camera I can use only gain and abs_exposure parameter (V4Lc linux ubuntu) ... my problem is change abs_exposure parameter duringa a day from 160 to 600 automatically (These values ​​have been tested throughout the day and in all conditions ... ranging from 160 min to 600 max I can get a great object-detenction). The values ​​must change with the different light of the day ... I was wondering if is possible to use the camera to be able to do this and how ...

There are many highlights that a sensor may not see .... but perhaps by calculating the entire amount of the white image and use it as a value might be an idea ....

Regards gfx

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Changing the camera value, will need to be done with the camera SDK, if it exists at all. Secondly, do you want to define the amount of light from the input images itself in relation to the exposure parameter?

StevenPuttemans gravatar imageStevenPuttemans ( 2016-10-04 05:58:34 -0500 )edit

@StevenPuttemans Secondly, do you want to define the amount of light from the input images itself in relation to the exposure parameter?

Yess...

gfx gravatar imagegfx ( 2016-10-08 06:13:33 -0500 )edit

I am not sure of that is even possible. To much light will mean that you have oversaturated spots while not enough will leave a very dark content, but defining regions in between seems impossible purely based on 2D imagery?

StevenPuttemans gravatar imageStevenPuttemans ( 2016-10-10 03:36:49 -0500 )edit

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answered 2016-10-21 12:05:20 -0500

gfx gravatar image

at these link PID for exsposure_absolute based on green channel of hist ...

These solution solved my problem ... I use the PID calculation only 1 time every 8 grabbing loop time ...a loop time have a delay of 50ms for decrease cpu usage .... (after grab a show in "realtime" the video on monitor)...

regards Giorgio

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Asked: 2016-10-03 06:35:10 -0500

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Last updated: Oct 21 '16