In the grey world AWB case, if no colour gains are contained in the
tuning file, the colour gains get reset to 1 when the colour temperature
is set manually. This is unexpected and undesirable. Allow the
gainsFromColourTemp() function to return a std::nullopt to handle that
case.
While at it, remove an unnecessary import from rkisp1/algorithms/awb.h.
Signed-off-by: Stefan Klug <stefan.klug@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
The convention in libcamera is not to prefix getters with a 'get'
prefix. Rename the AwbStats::getRGBMeans() function accordingly.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Stefan Klug <stefan.klug@ideasonboard.com>
Function names are followed by parentheses in doxygen documentation
blocks as convention in libcamera. Add missing parentheses in the
AwbAlgorithm documentation.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Stefan Klug <stefan.klug@ideasonboard.com>
Sort the documentation of the class members in the same order as the
member declaration in the class definition, as is customary in
libcamera.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Stefan Klug <stefan.klug@ideasonboard.com>
The original code used to specify the probabilities in log space and
scaled for the RaspberryPi hardware with 192 AWB measurement points.
This is reasonable as the whole algorithm makes use of unitless numbers
to prefer some colour temperatures based on a lux level. These numbers
are then hand tuned with the specific device in mind.
This has two shortcomings:
1. The linear interpolation of PWLs in log space is mathematically
incorrect. The outcome might still be ok, as both spaces (log and
linear) are monotonic, but it is still not "right".
2. Having unitless numbers gets more error prone when we try to
harmonize the behavior over multiple platforms.
Change the algorithm to interpret the numbers as being in linear space.
This makes the interpolation mathematically correct at the expense of a
few log operations.
To account for that change, update the numbers in the tuning example
file with the linear counterparts scaled to one AWB zone measurement.
Signed-off-by: Stefan Klug <stefan.klug@ideasonboard.com>
Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
Reviewed-by: Daniel Scally <dan.scally@ideasonboard.com>
The AWB modes are specified in the libcamera core controls. It is
therefore quite likely that every AWB algorithm will implement them. Add
helper functions for parsing and storing the configured modes in the
AwbAlgorithm base class.
Signed-off-by: Stefan Klug <stefan.klug@ideasonboard.com>
Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
Reviewed-by: Daniel Scally <dan.scally@ideasonboard.com>
Add a class to provide a generic interface for auto white balance
algorithms. Concrete AWB algorithms are expected to subclass the
AwbAlgorithm class to implement their functionality.
IPAs are expected to subclass the AwbStats class and implement the
necessary functions to give the algorithm access to the hardware
specific statistics data.
Signed-off-by: Stefan Klug <stefan.klug@ideasonboard.com>
Reviewed-by: Daniel Scally <dan.scally@ideasonboard.com>
Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
Stefan Klug
Laurent Pinchart