Brussels / 4 & 5 February 2023


Sharp photos and short movies on a mobile phone

Phones running Linux became reality in last few years, and they do have cameras, but taking sharp and correctly exposed photos is still not easy, and neither is recording even short movies. I'm trying to change that, and have some successes I'd like to talk about, but there is more work are more challenges in front of us.

There are three major platforms available today: PinePhone, Librem 5 and PinePhone Pro. PinePhone includes "smart" camera sensor, which is able to do auto-exposure, auto-focus and JPEG compression on its own. Capturing good photos is relatively simple using Megapixels. Capturing 2MP, 30fps video is possible with some "interesting" solutions I'll describe. Librem 5 is much more interesting. It includes dumb 13MP sensor, with support for phase-detection auto focus. Auto-exposure and auto-focus needs to be done in software, with auto-focus being quite complex and requiring different solutions based on use case. I do have unoptimized solutions for auto-exposure and auto-focus in Millipixels project, but they really belong to libcamera. It is possible to capture 0.8MP, 20fps movie. There's really more work to be done on all sides, including kernel -- bayer10 support, caching, libcamera and applications.


Pavel Machek