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

[David Plowman]

Hi Laurent

Thanks for the review.

On Thu, 23 Nov 2023 at 12:27, Laurent Pinchart
<laurent.pinchart at ideasonboard.com> wrote:
>
> Hi David,
>
> Thank you for the patch.
>
> On Fri, Nov 10, 2023 at 04:14:33PM +0000, David Plowman via libcamera-devel wrote:
> > ColourTemperature is now exported as a writable control so that
> > algorithms can set it directly.
>
> I'm puzzled here. You mention algorithms, but the patch exposes the
> control as being writable from applications. Is it a typo in the commit
> message ? If so, what's the use case ? control_ids.yaml documents the
> control as

Yes, I'll change "algorithms" to "applications".

>
>   - ColourTemperature:
>       type: int32_t
>       description: Report the current estimate of the colour temperature, in
>         kelvin, for this frame. The ColourTemperature control can only be
>         returned in metadata.
>
> so this would need to be updated as a prerequisite for this patch.

I'll add a patch before this one to change that description.

Thanks!
David

>
> > 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;
> > +
> > +                     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;
> > +                     }
> > +
> > +                     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;
>
> --
> Regards,
>
> Laurent Pinchart