On Sat, 7 Jan 2023 22:58:41 +0100 Sophie Friedrich <lkml@xxxxxxxxxxxx> wrote: > Hello people, > > over the past months I've written a driver for the Guide MobIR Air¹ > USB-C thermal camera. The driver uses v4l2loopback and runs in user > space with python.² The driver manages camera state, calibration and > conversion of the raw microbolometer to temperature values. > > In my research I couldn't find any mentions of a thermal camera support > in the Linux kernel nor the media subsystem, so I assume I'm the first > to ask here and we would presumably need lay out some ground work. > > The current camera driver outputs the temperature in the Y16 format as > Kelvin * 100 (i.e. 28056 (raw) -> 280.56K -> 7.41°C). This allows for > further processing down the line with i.e. OpenCV, but has its > limitations. Especially as temps of only up to 382.2°C can be displayed > currently. > > Does it seem feasible to integrate support for thermal cameras in the > Linux kernel and more specifically in the v4l2 subsystem? Hi, since no-one else replied to you yet, I thought to mention my 2c (I don't really do camera stuff myself so far): Perhaps the best place is to reach out to the libcamera community: https://libcamera.org/ It sounds to me like you want to do some hardware-specific processing in userspace, and it might not be great to try to come up with a generic thermal camera API at the kernel UAPI level. That's where libcamera fits in. As for the pixel type, maybe use a floating-point type to avoid range/precision problems? E.g. DRM_FORMAT_R32F for application facing API. That format does not seem to exist yet, but it's trivial to add into kernel's drm_fourcc.h and should be well accepted IMO. Thanks, pq > > [1]: > https://www.guideir.com/products/mobileaccessories/mobirair/data_300.html > [2]: https://github.com/tyalie/pyMobirAir-v4l2/
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