[libcamera-devel] [PATCH] ipa: rpi: awb: Make is possible to set the colour temperature directly

[Kieran Bingham]

Quoting David Plowman via libcamera-devel (2023-11-10 16:14:33)
> ColourTemperature is now exported as a writable control so that
> algorithms can set it directly. The AWB algorithm class now requires a
> method to be provided to perform this operation. The method should
> clamp the passed value to the calibrated range known to the algorithm.
> 
> The default range is set very wide to cover all conceivable future AWB
> calibrations. It will always be clamped before use.
> 
> Signed-off-by: David Plowman <david.plowman at raspberrypi.com>
> ---
>  src/ipa/rpi/common/ipa_base.cpp        | 20 ++++++++++++++++++++
>  src/ipa/rpi/controller/awb_algorithm.h |  1 +
>  src/ipa/rpi/controller/rpi/awb.cpp     | 18 ++++++++++++++++++
>  src/ipa/rpi/controller/rpi/awb.h       |  1 +
>  4 files changed, 40 insertions(+)
> 
> diff --git a/src/ipa/rpi/common/ipa_base.cpp b/src/ipa/rpi/common/ipa_base.cpp
> index 97a32522..cd1d6e3d 100644
> --- a/src/ipa/rpi/common/ipa_base.cpp
> +++ b/src/ipa/rpi/common/ipa_base.cpp
> @@ -80,6 +80,7 @@ const ControlInfoMap::Map ipaColourControls{
>         { &controls::AwbEnable, ControlInfo(false, true) },
>         { &controls::AwbMode, ControlInfo(controls::AwbModeValues) },
>         { &controls::ColourGains, ControlInfo(0.0f, 32.0f) },
> +       { &controls::ColourTemperature, ControlInfo(100, 100000) },
>         { &controls::Saturation, ControlInfo(0.0f, 32.0f, 1.0f) },
>  };
>  
> @@ -972,6 +973,25 @@ void IpaBase::applyControls(const ControlList &controls)
>                         break;
>                 }
>  
> +               case controls::COLOUR_TEMPERATURE: {
> +                       /* Silently ignore this control for a mono sensor. */
> +                       if (monoSensor_)
> +                               break;

I wonder if this is where the construction of the control info map
should be handled / supported by the algorithms so they can populate it
correctly / dynamically based on what they can handle. But that's not
for this patch - and I suspect this is ok.


> +
> +                       auto temperatureK = ctrl.second.get<int32_t>();
> +                       RPiController::AwbAlgorithm *awb = dynamic_cast<RPiController::AwbAlgorithm *>(
> +                               controller_.getAlgorithm("awb"));
> +                       if (!awb) {
> +                               LOG(IPARPI, Warning)
> +                                       << "Could not set COLOUR_TEMPERATURE - no AWB algorithm";
> +                               break;

I guess it would also prevent exposing a control when there's no
algorithm to implement/support it though. Still - for now this seems
like all that could be done here then.


But otherwise


Reviewed-by: Kieran Bingham <kieran.bingham at ideasonboard.com>

> +                       }
> +
> +                       awb->setColourTemperature(temperatureK);
> +                       /* This metadata will get reported back automatically. */
> +                       break;
> +               }
> +
>                 case controls::BRIGHTNESS: {
>                         RPiController::ContrastAlgorithm *contrast = dynamic_cast<RPiController::ContrastAlgorithm *>(
>                                 controller_.getAlgorithm("contrast"));
> diff --git a/src/ipa/rpi/controller/awb_algorithm.h b/src/ipa/rpi/controller/awb_algorithm.h
> index 8462c4db..d966dfa8 100644
> --- a/src/ipa/rpi/controller/awb_algorithm.h
> +++ b/src/ipa/rpi/controller/awb_algorithm.h
> @@ -18,6 +18,7 @@ public:
>         virtual unsigned int getConvergenceFrames() const = 0;
>         virtual void setMode(std::string const &modeName) = 0;
>         virtual void setManualGains(double manualR, double manualB) = 0;
> +       virtual void setColourTemperature(double temperatureK) = 0;
>         virtual void enableAuto() = 0;
>         virtual void disableAuto() = 0;
>  };
> diff --git a/src/ipa/rpi/controller/rpi/awb.cpp b/src/ipa/rpi/controller/rpi/awb.cpp
> index 5ae0c2fa..0918e20d 100644
> --- a/src/ipa/rpi/controller/rpi/awb.cpp
> +++ b/src/ipa/rpi/controller/rpi/awb.cpp
> @@ -275,6 +275,24 @@ void Awb::setManualGains(double manualR, double manualB)
>         }
>  }
>  
> +void Awb::setColourTemperature(double temperatureK)
> +{
> +       if (!config_.bayes) {
> +               LOG(RPiAwb, Warning) << "AWB uncalibrated - cannot set colour temperature";
> +               return;
> +       }
> +
> +       temperatureK = config_.ctR.domain().clip(temperatureK);
> +       manualR_ = 1 / config_.ctR.eval(temperatureK);
> +       manualB_ = 1 / config_.ctB.eval(temperatureK);
> +
> +       syncResults_.temperatureK = temperatureK;
> +       syncResults_.gainR = manualR_;
> +       syncResults_.gainG = 1.0;
> +       syncResults_.gainB = manualB_;
> +       prevSyncResults_ = syncResults_;
> +}
> +
>  void Awb::switchMode([[maybe_unused]] CameraMode const &cameraMode,
>                      Metadata *metadata)
>  {
> diff --git a/src/ipa/rpi/controller/rpi/awb.h b/src/ipa/rpi/controller/rpi/awb.h
> index e7d49cd8..dbd79eda 100644
> --- a/src/ipa/rpi/controller/rpi/awb.h
> +++ b/src/ipa/rpi/controller/rpi/awb.h
> @@ -97,6 +97,7 @@ public:
>         unsigned int getConvergenceFrames() const override;
>         void setMode(std::string const &name) override;
>         void setManualGains(double manualR, double manualB) override;
> +       void setColourTemperature(double temperatureK) override;
>         void enableAuto() override;
>         void disableAuto() override;
>         void switchMode(CameraMode const &cameraMode, Metadata *metadata) override;
> -- 
> 2.39.2
>