Trying to get some data for underwater white balance

[grassybreakfast]

By the way, I've found some very interesting papers on doing different white balance on different parts of images, based on estimating transmission. Actually also looks quite practical to implement, so I may play with that as well. Seems to work quite a bit better than whole-image white balancing.

Eg Underwater image and video dehazing with pure haze region segmentation

 

[Pearlman]

Ah yeah that makes sense. Most action cameras don't have that (DJI Action cameras have some kind of white balance sensor, but no one really knows how it works). Yeah I think for now I'll just do histogram stretching (functionally the same as using a white balance sensor, but post-encoding rather than pre-encoding, so not as effective use of bits).

I have a DJI Action3 and the WB sensor is embedded in the body inside the ‘O’ of the Osmo lettering. Last I looked it up on a generic how stuff works search, and IIRC It was just sensing the 3 primaries and performing WB correction. I believe GoPro and Insta360 do not use a separate WB sensor but it’s embedded behind the main lens of their action cams and they still perform UCC to varying degrees of improvement in-camera over the original footage … just like the DJI with its separate sensors.

Unfortunately for DJI this means using some lenses like the AOI UWL-03 and other external macro lens attachments end up covering its WB sensor and you lose the UCC function because the sensor is blocked by the ring of the QR adapter…