Commit Graph

8 Commits

Author SHA1 Message Date
Milan Zamazal
d92f5f5402 libcamera: ipa: simple: Separate saturation from CCM
Saturation adjustments are implemented using matrix operations.  They
are currently applied to the colour correction matrix.  Let's move them
to a newly introduced separate "Adjust" algorithm.

This separation has the following advantages:

- It allows disabling general colour adjustments algorithms without
  disabling the CCM algorithm.

- It keeps the CCM separated from other corrections.

- It's generally cleaner.

Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Robert Mader <robert.mader@collabora.com>
Signed-off-by: Milan Zamazal <mzamazal@redhat.com>
Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
2026-01-28 15:20:32 +00:00
Milan Zamazal
82ed6c19c2 libcamera: ipa: simple: Initialise the general correction matrix
The combined matrix must be reset to the initial value before each frame
is prepared.  This must be done outside algorithms because any of the
algorithms may be disabled while the matrix must be always initialised.

Let's initialise the combined matrix to the identity matrix (which keeps
the pixel values unchanged) in software ISP just before calling
`prepare' on the algorithms.

Matrix updates can no longer be skipped in ccm.cpp, otherwise the CCM
won't be applied if there is no temperature or saturation change.  We
explicitly track whether the CCM has been set up completely rather than
relying on the frame number, to avoid missing the initialisation in case
the first frame is skipped due to some error.

Reviewed-by: Robert Mader <robert.mader@collabora.com>
Signed-off-by: Milan Zamazal <mzamazal@redhat.com>
Acked-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
2026-01-28 15:20:32 +00:00
Milan Zamazal
5f3cdafe0f libcamera: ipa: simple: Introduce a general correction matrix
Let's introduce IPAActiveState::combinedMatrix that is separate from
IPAActiveState::ccm and represents the overall correction matrix, not
only the sensor colour correction matrix.

IPAActiveState::ccm still includes everything; this is changed in the
followup patch.

Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Barnabás Pőcze <barnabas.pocze@ideasonboard.com>
Signed-off-by: Milan Zamazal <mzamazal@redhat.com>
Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
2026-01-28 15:20:32 +00:00
Milan Zamazal
77942a3bd0 libcamera: ipa: simple: Generalize tracking matrix changes
IPAActiveState::ccm stores the colour correction matrix (CCM) and
whether it has been changed.  The change flag is later used when
recomputing or not the lookup tables.

But the CCM may include other corrections than just the sensor colour
correction, for example white balance and saturation adjustments.  These
things should be separated and IPAActiveState::ccm should represent just
the CCM itself.

As the first step towards that cleanup, let's separate the change flag
from the CCM.  And wrap the only remaining member of
IPAActiveState::ccm.

Also, let's reset the separated change flag in the lookup tables; it'll
be no longer tied to just CCM handling.

This patch doesn't change actual behaviour and it still reports the
combined matrix as CCM in metadata.  This is addressed in the followup
patches.

Reviewed-by: Bryan O'Donoghue <bod.linux@nxsw.ie>
Reviewed-by: Barnabás Pőcze <barnabas.pocze@ideasonboard.com>
Signed-off-by: Milan Zamazal <mzamazal@redhat.com>
Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
2026-01-28 15:19:51 +00:00
Milan Zamazal
3dbe06a15f libcamera: ipa: simple: Unwrap IPAFrameContext::ccm
The struct has only one member and there is no immediate need to add
more.  Let's use the member directly, to make things a bit simpler.

Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Barnabás Pőcze <barnabas.pocze@ideasonboard.com>
Signed-off-by: Milan Zamazal <mzamazal@redhat.com>
Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
2026-01-28 15:19:51 +00:00
Milan Zamazal
59ac34b728 libcamera: software_isp: Add saturation control
Saturation control is added on top of the colour correction matrix.  A
method of saturation adjustment that can be fully integrated into the
colour correction matrix is used.  The control is available only if Ccm
algorithm is enabled.

The control uses 0.0-2.0 value range, with 1.0 being unmodified
saturation, 0.0 full desaturation and 2.0 quite saturated.

The saturation is adjusted by converting to Y'CbCr colour space,
applying the saturation value on the colour axes, and converting back to
RGB.  ITU-R BT.601 conversion is used to convert between the colour
spaces, for no particular reason.

The colour correction matrix is applied before gamma and the given
matrix is suitable for such a case.  Alternatively, the transformation
used in libcamera rpi ccm.cpp could be used.

Signed-off-by: Milan Zamazal <mzamazal@redhat.com>
Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
2025-06-01 23:08:01 +01:00
Milan Zamazal
ac30686556 libcamera: software_isp: Track whether CCM is enabled
Applying color correction matrix (CCM) in software ISP is optional due
to performance reasons.  CCM is applied if and only if `Ccm' algorithm
is present in the tuning file.

Software ISP debayering is a performance critical piece of code and we
do not want to use dynamic conditionals there.  Therefore we pass
information about CCM application to debayering configuration and let it
select the right versions of debayering functions using templates.  This
is a trick similar to the previously used one for adding or not adding
an alpha channel to the output.

Debayering gets this information but it ignores it in this patch.
Actual processing with CCM is added in the followup patch.

Signed-off-by: Milan Zamazal <mzamazal@redhat.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Milan Zamazal <mzamazal@redhat.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
2025-03-26 10:45:01 +00:00
Milan Zamazal
38ec74fb40 libcamera: software_isp: Add CCM algorithm
This patch adds color correction matrix (CCM) algorithm to software ISP.
It is based on the corresponding algorithm in rkisp1.

The primary difference against hardware pipelines is that applying the
CCM is optional.  Applying CCM causes a significant slowdown, time
needed to process a frame raises by 40-90% on tested platforms.  If CCM
is really needed, it can be applied, if not, it's better to stick
without it.  This can be configured by presence or omission of Ccm
algorithm in the tuning file.

CCM is changed only if the determined temperature changes by at least
100 K (an arbitrarily selected value), to avoid recomputing the matrices
and lookup tables all the time.

Since the CCM is float, rather than double, to use the same type as in
the rkisp1 pipeline, the type of color gains is changed from double to
float.

The outputs of the algorithm are not used yet, they will be enabled in
followup patches.

Signed-off-by: Milan Zamazal <mzamazal@redhat.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Milan Zamazal <mzamazal@redhat.com>
Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
2025-03-26 10:45:01 +00:00