[PATCH v1 3/6] ipa: rkisp1: awb: Implement ColourTemperature control

[Kieran Bingham]

Quoting Stefan Klug (2024-08-05 13:05:04)
> There are many use-cases (tuning-validation, working in static
> environments) where a manual ColourTemperature control is helpful.
> Implement that by interpolating and applying the white balance gains
> from the tuning file according to the requested colour temperature. If
> colour gains are provided on the same request, they take precedence. As
> the colour temperature reported in the metadata is always based on the
> measurements, we don't have to touch that.
> 
> Note that in the automatic case, the colour gains are still based on the
> gray world model and the ones from the tuning file get ignored.
> 
> Signed-off-by: Stefan Klug <stefan.klug at ideasonboard.com>
> ---
>  src/ipa/rkisp1/algorithms/awb.cpp | 20 ++++++++++++++++++++
>  1 file changed, 20 insertions(+)
> 
> diff --git a/src/ipa/rkisp1/algorithms/awb.cpp b/src/ipa/rkisp1/algorithms/awb.cpp
> index 957d24fe3425..d482eda5b541 100644
> --- a/src/ipa/rkisp1/algorithms/awb.cpp
> +++ b/src/ipa/rkisp1/algorithms/awb.cpp
> @@ -31,6 +31,10 @@ namespace ipa::rkisp1::algorithms {
>  
>  LOG_DEFINE_CATEGORY(RkISP1Awb)
>  
> +constexpr int32_t kMinColourTemperature = 2500;
> +constexpr int32_t kMaxColourTemperature = 10000;
> +constexpr int32_t kDefaultColourTemperature = 6500;
> +
>  /* Minimum mean value below which AWB can't operate. */
>  constexpr double kMeanMinThreshold = 2.0;
>  
> @@ -44,6 +48,11 @@ Awb::Awb()
>   */
>  int Awb::init(IPAContext &context, const YamlObject &tuningData)
>  {
> +       auto &cmap = context.ctrlMap;
> +       cmap[&controls::ColourTemperature] = ControlInfo(kMinColourTemperature,
> +                                                        kMaxColourTemperature,
> +                                                        kDefaultColourTemperature);
> +

Should this control only be exposed if there are gains available in the
tuning file?

Can/Should the minColourTemperature/maxColourTemperature be based on the
values that are available in the Tuning file? Or does the interpolator
make this possible to extend beyond the limits calibrated if it can
extrapolate for wider values?



>         MatrixInterpolator<double, 2, 1> gains;
>         int ret = gains.readYaml(tuningData["gains"], "ct", "gains");
>         if (ret < 0)
> @@ -113,6 +122,17 @@ void Awb::queueRequest(IPAContext &context,
>                         << ", blue: " << awb.gains.manual.blue;
>         }
>  
> +       const auto &colourTemperature = controls.get(controls::ColourTemperature);
> +       if (colourTemperature && !awb.autoEnabled && gains_ && !colourGains) {
> +               Matrix<double, 2, 1> gains = gains_->get(*colourTemperature);
> +               awb.gains.manual.red = gains[0][0];
> +               awb.gains.manual.blue = gains[1][0];
> +
> +               LOG(RkISP1Awb, Debug)
> +                       << "Set colour gains to red: " << awb.gains.manual.red
> +                       << ", blue: " << awb.gains.manual.blue;
> +       }
> +
>         frameContext.awb.autoEnabled = awb.autoEnabled;
>  
>         if (!awb.autoEnabled) {
> -- 
> 2.43.0
>