[PATCH v6 17/18] libcamera: software_isp: Apply black level compensation

[Milan Zamazal]

Laurent Pinchart <laurent.pinchart at ideasonboard.com> writes:

> As for other part of this series, I'm fine starting with this initial
> implementation and improving it, but I think the black level should
> eventually be moved before debayering, and ideally the colour gains as
> well. I understand the need for optimizations to lower the CPU
> consumption, but at the same time I don't feel comfortable building up
> on top of an implementation that may work a bit more by chance than by
> correctness, as that's not very maintainable.

Hi Laurent,

to make sure we understand each other correctly: Can we agree that "be moved
before debayering" above means primarily separating the level adjustments
computations from debayering code and building them (together with other stuff)
on top of libipa/algorithm.h?  Rather than first applying the corrections on the
data and only then perform debayering, which luxury we cannot afford, at least
on CPU?  I.e. the first step could be something like
https://gitlab.freedesktop.org/mzamazal/libcamera-softisp/-/commit/6180d853005bb956b3d2469576b139ff523b76ad ?

Regards,
Milan