[RFC PATCH v2 11/12] ipa: rkisp1: awb: Use RGB class to store colour gains

Milan Zamazal mzamazal at redhat.com
Mon Nov 18 14:49:27 CET 2024


Laurent Pinchart <laurent.pinchart at ideasonboard.com> writes:

> Replace the individual colour gains with instances of the RGB<double>
> class. This simplifies the code that performs calculations on the gains.

Nice, thank you.

Reviewed-by: Milan Zamazal <mzamazal at redhat.com>

(Some very minor comments below.)

> Signed-off-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
> ---
>  src/ipa/rkisp1/algorithms/awb.cpp | 102 ++++++++++++------------------
>  src/ipa/rkisp1/algorithms/awb.h   |   2 +-
>  src/ipa/rkisp1/ipa_context.cpp    |  31 +--------
>  src/ipa/rkisp1/ipa_context.h      |  20 ++----
>  4 files changed, 48 insertions(+), 107 deletions(-)
>
> diff --git a/src/ipa/rkisp1/algorithms/awb.cpp b/src/ipa/rkisp1/algorithms/awb.cpp
> index b3c00bef9b7e..1c572055acdd 100644
> --- a/src/ipa/rkisp1/algorithms/awb.cpp
> +++ b/src/ipa/rkisp1/algorithms/awb.cpp
> @@ -45,12 +45,8 @@ Awb::Awb()
>  int Awb::configure(IPAContext &context,
>  		   const IPACameraSensorInfo &configInfo)
>  {
> -	context.activeState.awb.gains.manual.red = 1.0;
> -	context.activeState.awb.gains.manual.blue = 1.0;
> -	context.activeState.awb.gains.manual.green = 1.0;
> -	context.activeState.awb.gains.automatic.red = 1.0;
> -	context.activeState.awb.gains.automatic.blue = 1.0;
> -	context.activeState.awb.gains.automatic.green = 1.0;
> +	context.activeState.awb.gains.manual = RGB<double>({ 1.0, 1.0, 1.0 });
> +	context.activeState.awb.gains.automatic = RGB<double>({ 1.0, 1.0, 1.0 });
>  	context.activeState.awb.autoEnabled = true;
>  
>  	/*
> @@ -87,21 +83,17 @@ void Awb::queueRequest(IPAContext &context,
>  
>  	const auto &colourGains = controls.get(controls::ColourGains);
>  	if (colourGains && !awb.autoEnabled) {
> -		awb.gains.manual.red = (*colourGains)[0];
> -		awb.gains.manual.blue = (*colourGains)[1];
> +		awb.gains.manual.r() = (*colourGains)[0];
> +		awb.gains.manual.b() = (*colourGains)[1];
>  
>  		LOG(RkISP1Awb, Debug)
> -			<< "Set colour gains to red: " << awb.gains.manual.red
> -			<< ", blue: " << awb.gains.manual.blue;
> +			<< "Set colour gains to " << awb.gains.manual;
>  	}
>  
>  	frameContext.awb.autoEnabled = awb.autoEnabled;
>  
> -	if (!awb.autoEnabled) {
> -		frameContext.awb.gains.red = awb.gains.manual.red;
> -		frameContext.awb.gains.green = 1.0;
> -		frameContext.awb.gains.blue = awb.gains.manual.blue;
> -	}
> +	if (!awb.autoEnabled)
> +		frameContext.awb.gains = awb.gains.manual;
>  }
>  
>  /**
> @@ -114,19 +106,16 @@ void Awb::prepare(IPAContext &context, const uint32_t frame,
>  	 * This is the latest time we can read the active state. This is the
>  	 * most up-to-date automatic values we can read.
>  	 */
> -	if (frameContext.awb.autoEnabled) {
> -		frameContext.awb.gains.red = context.activeState.awb.gains.automatic.red;
> -		frameContext.awb.gains.green = context.activeState.awb.gains.automatic.green;
> -		frameContext.awb.gains.blue = context.activeState.awb.gains.automatic.blue;
> -	}
> +	if (frameContext.awb.autoEnabled)
> +		frameContext.awb.gains = context.activeState.awb.gains.automatic;
>  
>  	auto gainConfig = params->block<BlockType::AwbGain>();
>  	gainConfig.setEnabled(true);
>  
> -	gainConfig->gain_green_b = std::clamp<int>(256 * frameContext.awb.gains.green, 0, 0x3ff);
> -	gainConfig->gain_blue = std::clamp<int>(256 * frameContext.awb.gains.blue, 0, 0x3ff);
> -	gainConfig->gain_red = std::clamp<int>(256 * frameContext.awb.gains.red, 0, 0x3ff);
> -	gainConfig->gain_green_r = std::clamp<int>(256 * frameContext.awb.gains.green, 0, 0x3ff);
> +	gainConfig->gain_green_b = std::clamp<int>(256 * frameContext.awb.gains.g(), 0, 0x3ff);
> +	gainConfig->gain_blue = std::clamp<int>(256 * frameContext.awb.gains.b(), 0, 0x3ff);
> +	gainConfig->gain_red = std::clamp<int>(256 * frameContext.awb.gains.r(), 0, 0x3ff);
> +	gainConfig->gain_green_r = std::clamp<int>(256 * frameContext.awb.gains.g(), 0, 0x3ff);
>  
>  	/* If we have already set the AWB measurement parameters, return. */
>  	if (frame > 0)
> @@ -178,12 +167,12 @@ void Awb::prepare(IPAContext &context, const uint32_t frame,
>  	}
>  }
>  
> -uint32_t Awb::estimateCCT(double red, double green, double blue)
> +uint32_t Awb::estimateCCT(const RGB<double> &rgb)

Note this is in conflict with a recently posted patch moving this to
the common IPA.

>  {
>  	/* Convert the RGB values to CIE tristimulus values (XYZ) */
> -	double X = (-0.14282) * (red) + (1.54924) * (green) + (-0.95641) * (blue);
> -	double Y = (-0.32466) * (red) + (1.57837) * (green) + (-0.73191) * (blue);
> -	double Z = (-0.68202) * (red) + (0.77073) * (green) + (0.56332) * (blue);
> +	double X = -0.14282 * rgb.r() + 1.54924 * rgb.g() - 0.95641 * rgb.b();
> +	double Y = -0.32466 * rgb.r() + 1.57837 * rgb.g() - 0.73191 * rgb.b();
> +	double Z = -0.68202 * rgb.r() + 0.77073 * rgb.g() + 0.56332 * rgb.b();

Does this demonstrate that operator* would be more handy as a dot product?

>  	/* Calculate the normalized chromaticity values */
>  	double x = X / (X + Y + Z);
> @@ -206,14 +195,12 @@ void Awb::process(IPAContext &context,
>  	const rkisp1_cif_isp_stat *params = &stats->params;
>  	const rkisp1_cif_isp_awb_stat *awb = &params->awb;
>  	IPAActiveState &activeState = context.activeState;
> -	double greenMean;
> -	double redMean;
> -	double blueMean;
> +	RGB<double> rgbMeans;
>  
>  	metadata.set(controls::AwbEnable, frameContext.awb.autoEnabled);
>  	metadata.set(controls::ColourGains, {
> -			static_cast<float>(frameContext.awb.gains.red),
> -			static_cast<float>(frameContext.awb.gains.blue)
> +			static_cast<float>(frameContext.awb.gains.r()),
> +			static_cast<float>(frameContext.awb.gains.b())
>  		});
>  	metadata.set(controls::ColourTemperature, activeState.awb.temperatureK);
>  
> @@ -223,9 +210,9 @@ void Awb::process(IPAContext &context,
>  	}
>  
>  	if (rgbMode_) {
> -		greenMean = awb->awb_mean[0].mean_y_or_g;
> -		redMean = awb->awb_mean[0].mean_cr_or_r;
> -		blueMean = awb->awb_mean[0].mean_cb_or_b;
> +		rgbMeans.r() = awb->awb_mean[0].mean_cr_or_r;
> +		rgbMeans.g() = awb->awb_mean[0].mean_y_or_g;
> +		rgbMeans.b() = awb->awb_mean[0].mean_cb_or_b;
>  	} else {
>  		/* Get the YCbCr mean values */
>  		double yMean = awb->awb_mean[0].mean_y_or_g;
> @@ -247,9 +234,9 @@ void Awb::process(IPAContext &context,
>  		yMean -= 16;
>  		cbMean -= 128;
>  		crMean -= 128;
> -		redMean = 1.1636 * yMean - 0.0623 * cbMean + 1.6008 * crMean;
> -		greenMean = 1.1636 * yMean - 0.4045 * cbMean - 0.7949 * crMean;
> -		blueMean = 1.1636 * yMean + 1.9912 * cbMean - 0.0250 * crMean;
> +		rgbMeans.r() = 1.1636 * yMean - 0.0623 * cbMean + 1.6008 * crMean;
> +		rgbMeans.g() = 1.1636 * yMean - 0.4045 * cbMean - 0.7949 * crMean;
> +		rgbMeans.b() = 1.1636 * yMean + 1.9912 * cbMean - 0.0250 * crMean;
>  
>  		/*
>  		 * Due to hardware rounding errors in the YCbCr means, the
> @@ -257,9 +244,7 @@ void Awb::process(IPAContext &context,
>  		 * negative gains, messing up calculation. Prevent this by
>  		 * clamping the means to positive values.
>  		 */
> -		redMean = std::max(redMean, 0.0);
> -		greenMean = std::max(greenMean, 0.0);
> -		blueMean = std::max(blueMean, 0.0);
> +		rgbMeans = rgbMeans.max(0.0);
>  	}
>  
>  	/*
> @@ -267,19 +252,17 @@ void Awb::process(IPAContext &context,
>  	 * divide by the gains that were used to get the raw means from the
>  	 * sensor.
>  	 */
> -	redMean /= frameContext.awb.gains.red;
> -	greenMean /= frameContext.awb.gains.green;
> -	blueMean /= frameContext.awb.gains.blue;
> +	rgbMeans /= frameContext.awb.gains;
>  
>  	/*
>  	 * If the means are too small we don't have enough information to
>  	 * meaningfully calculate gains. Freeze the algorithm in that case.
>  	 */
> -	if (redMean < kMeanMinThreshold && greenMean < kMeanMinThreshold &&
> -	    blueMean < kMeanMinThreshold)
> +	if (rgbMeans.r() < kMeanMinThreshold && rgbMeans.g() < kMeanMinThreshold &&
> +	    rgbMeans.b() < kMeanMinThreshold)

Would it be worth to define also operator< ?

>  		return;
>  
> -	activeState.awb.temperatureK = estimateCCT(redMean, greenMean, blueMean);
> +	activeState.awb.temperatureK = estimateCCT(rgbMeans);
>  
>  	/* Metadata shall contain the up to date measurement */
>  	metadata.set(controls::ColourTemperature, activeState.awb.temperatureK);
> @@ -289,8 +272,11 @@ void Awb::process(IPAContext &context,
>  	 * gain is hardcoded to 1.0. Avoid divisions by zero by clamping the
>  	 * divisor to a minimum value of 1.0.
>  	 */
> -	double redGain = greenMean / std::max(redMean, 1.0);
> -	double blueGain = greenMean / std::max(blueMean, 1.0);
> +	RGB<double> gains({
> +		rgbMeans.g() / std::max(rgbMeans.r(), 1.0),
> +		1.0,
> +		rgbMeans.g() / std::max(rgbMeans.b(), 1.0)
> +	});
>  
>  	/*
>  	 * Clamp the gain values to the hardware, which expresses gains as Q2.8
> @@ -298,24 +284,18 @@ void Awb::process(IPAContext &context,
>  	 * divisions by zero when computing the raw means in subsequent
>  	 * iterations.
>  	 */
> -	redGain = std::clamp(redGain, 1.0 / 256, 1023.0 / 256);
> -	blueGain = std::clamp(blueGain, 1.0 / 256, 1023.0 / 256);
> +	gains = gains.max(1.0 / 256).min(1023.0 / 256);
>  
>  	/* Filter the values to avoid oscillations. */
>  	double speed = 0.2;
> -	redGain = speed * redGain + (1 - speed) * activeState.awb.gains.automatic.red;
> -	blueGain = speed * blueGain + (1 - speed) * activeState.awb.gains.automatic.blue;
> +	gains = gains * speed + activeState.awb.gains.automatic * (1 - speed);
>  
> -	activeState.awb.gains.automatic.red = redGain;
> -	activeState.awb.gains.automatic.blue = blueGain;
> -	activeState.awb.gains.automatic.green = 1.0;
> +	activeState.awb.gains.automatic = gains;
>  
>  	LOG(RkISP1Awb, Debug)
>  		<< std::showpoint
> -		<< "Means [" << redMean << ", " << greenMean << ", " << blueMean
> -		<< "], gains [" << activeState.awb.gains.automatic.red << ", "
> -		<< activeState.awb.gains.automatic.green << ", "
> -		<< activeState.awb.gains.automatic.blue << "], temp "
> +		<< "Means " << rgbMeans << ", gains "
> +		<< activeState.awb.gains.automatic << ", temp "
>  		<< activeState.awb.temperatureK << "K";
>  }
>  
> diff --git a/src/ipa/rkisp1/algorithms/awb.h b/src/ipa/rkisp1/algorithms/awb.h
> index b3b2c0bbb9ae..058c0fc53490 100644
> --- a/src/ipa/rkisp1/algorithms/awb.h
> +++ b/src/ipa/rkisp1/algorithms/awb.h
> @@ -32,7 +32,7 @@ public:
>  		     ControlList &metadata) override;
>  
>  private:
> -	uint32_t estimateCCT(double red, double green, double blue);
> +	uint32_t estimateCCT(const RGB<double> &rgb);
>  
>  	bool rgbMode_;
>  };
> diff --git a/src/ipa/rkisp1/ipa_context.cpp b/src/ipa/rkisp1/ipa_context.cpp
> index 14d0c02a2b32..8f545cd76d52 100644
> --- a/src/ipa/rkisp1/ipa_context.cpp
> +++ b/src/ipa/rkisp1/ipa_context.cpp
> @@ -188,30 +188,12 @@ namespace libcamera::ipa::rkisp1 {
>   * \struct IPAActiveState::awb.gains
>   * \brief White balance gains
>   *
> - * \struct IPAActiveState::awb.gains.manual
> + * \var IPAActiveState::awb.gains.manual
>   * \brief Manual white balance gains (set through requests)
>   *
> - * \var IPAActiveState::awb.gains.manual.red
> - * \brief Manual white balance gain for R channel
> - *
> - * \var IPAActiveState::awb.gains.manual.green
> - * \brief Manual white balance gain for G channel
> - *
> - * \var IPAActiveState::awb.gains.manual.blue
> - * \brief Manual white balance gain for B channel
> - *
> - * \struct IPAActiveState::awb.gains.automatic
> + * \var IPAActiveState::awb.gains.automatic
>   * \brief Automatic white balance gains (computed by the algorithm)
>   *
> - * \var IPAActiveState::awb.gains.automatic.red
> - * \brief Automatic white balance gain for R channel
> - *
> - * \var IPAActiveState::awb.gains.automatic.green
> - * \brief Automatic white balance gain for G channel
> - *
> - * \var IPAActiveState::awb.gains.automatic.blue
> - * \brief Automatic white balance gain for B channel
> - *
>   * \var IPAActiveState::awb.temperatureK
>   * \brief Estimated color temperature
>   *
> @@ -333,15 +315,6 @@ namespace libcamera::ipa::rkisp1 {
>   * \struct IPAFrameContext::awb.gains
>   * \brief White balance gains
>   *
> - * \var IPAFrameContext::awb.gains.red
> - * \brief White balance gain for R channel
> - *
> - * \var IPAFrameContext::awb.gains.green
> - * \brief White balance gain for G channel
> - *
> - * \var IPAFrameContext::awb.gains.blue
> - * \brief White balance gain for B channel
> - *
>   * \var IPAFrameContext::awb.temperatureK
>   * \brief Estimated color temperature
>   *
> diff --git a/src/ipa/rkisp1/ipa_context.h b/src/ipa/rkisp1/ipa_context.h
> index 7b93a9e9461d..b4dec0c3288d 100644
> --- a/src/ipa/rkisp1/ipa_context.h
> +++ b/src/ipa/rkisp1/ipa_context.h
> @@ -25,6 +25,7 @@
>  #include <libipa/camera_sensor_helper.h>
>  #include <libipa/fc_queue.h>
>  #include <libipa/matrix.h>
> +#include <libipa/vector.h>
>  
>  namespace libcamera {
>  
> @@ -87,16 +88,8 @@ struct IPAActiveState {
>  
>  	struct {
>  		struct {
> -			struct {
> -				double red;
> -				double green;
> -				double blue;
> -			} manual;
> -			struct {
> -				double red;
> -				double green;
> -				double blue;
> -			} automatic;
> +			RGB<double> manual;
> +			RGB<double> automatic;
>  		} gains;
>  
>  		unsigned int temperatureK;
> @@ -140,12 +133,7 @@ struct IPAFrameContext : public FrameContext {
>  	} agc;
>  
>  	struct {
> -		struct {
> -			double red;
> -			double green;
> -			double blue;
> -		} gains;
> -
> +		RGB<double> gains;
>  		bool autoEnabled;
>  	} awb;



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