Change video brightness

Hi all,

What is the best way to change CSI2 camera brightness on the fly?

I see only one option is using CUDA image processing to post process the NV12 frame & increase brightness. It is ok on FHD resolution, but on 4K resolution it might be time consuming.
Is there any capable to do brightness changing by ISP? I don’t see any APIs in libargus to do this. But I found tc.v2.user.presets[0].Brightness.Enable=FALSE; tc.v2.user.presets[0].Brightness.Value=1.0000; in ISP camera_overrides.isp file, but I believe this is not able to change on the fly.

Any thoughts? Thank you.

hello HnilND,

there’s sample application, argus_camera, it provides user-interface for sending camera controls during runtime, and apply these settings to change preview frames.

Hi Jerry,
Thank you for your reply.
I knew that argus_camera has user interface to change camera controls, via libargus API. But they are about exposure time, gain and isp gain range. It also has EV, saturation, but brightness setting is not a part of libargus API.
In general camera, we have a setting to change brightness (normally between 0-100%). I’m looking for similar option in libargus API.

Thank you.

hello HnilND,

I don’t understand, what the brightness setting you’re looking for?
please describe the actual use-case.

Hi Jerry,

The generic camera usually has a parameter to control how bright the video is (normally will have contrast setting also). When you want a more bright image, you just increase the brightness argument, …
For libargus, the exposure time, gain, isp gain are decided by ISP, we are only able to set the range of these. So ISP try to control these parameters to get a good output. But the target brightness of the output is likely fixed, no API to change the target brightness in ISP.

hello HnilND,

that’s something like exposure compensation. i.e. EV+1, +2…etc.
AE algorithm by default calculate whole capture frame to come out the exposure evaluation results.
may I know what’s the scene you’ve captured, is it captured under a high contrast environment?

please have a try to include AeRegion controls. you may select the interest region to obtain the exposure results close to your expectation.
please see-also Topic 82744 for code snippets to modify AE interest region.

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