[libcamera-devel] [PATCH 10/20] ipa: rpi: Prepare AWB for PiSP support

[Jacopo Mondi]

Hi Naush

On Fri, Oct 06, 2023 at 02:19:50PM +0100, Naushir Patuck via libcamera-devel wrote:
> Prepare the AWB algorithm to support the PiSP hardware. The key change
> is to factor in the LS correction in the AWB zone statistics. This is
> different from VC4 where the LS correction happens before statistics
> gathering.
>
> Signed-off-by: Naushir Patuck <naush at raspberrypi.com>
> Reviewed-by: David Plowman <david.plowman at raspberrypi.com>

Reviewed-by: Jacopo Mondi <jacopo.mondi at ideasonboard.com>

Thanks
  j

> ---
>  src/ipa/rpi/controller/rpi/awb.cpp | 29 ++++++++++++++++++++---------
>  1 file changed, 20 insertions(+), 9 deletions(-)
>
> diff --git a/src/ipa/rpi/controller/rpi/awb.cpp b/src/ipa/rpi/controller/rpi/awb.cpp
> index ef3435d66106..5ae0c2fad6e9 100644
> --- a/src/ipa/rpi/controller/rpi/awb.cpp
> +++ b/src/ipa/rpi/controller/rpi/awb.cpp
> @@ -12,6 +12,7 @@
>
>  #include "../lux_status.h"
>
> +#include "alsc_status.h"
>  #include "awb.h"
>
>  using namespace RPiController;
> @@ -398,18 +399,28 @@ void Awb::asyncFunc()
>  }
>
>  static void generateStats(std::vector<Awb::RGB> &zones,
> -			  RgbyRegions &stats, double minPixels,
> -			  double minG)
> +			  StatisticsPtr &stats, double minPixels,
> +			  double minG, Metadata &globalMetadata)
>  {
> -	for (auto const &region : stats) {
> +	std::scoped_lock<RPiController::Metadata> l(globalMetadata);
> +
> +	for (unsigned int i = 0; i < stats->awbRegions.numRegions(); i++) {
>  		Awb::RGB zone;
> +		auto &region = stats->awbRegions.get(i);
>  		if (region.counted >= minPixels) {
>  			zone.G = region.val.gSum / region.counted;
> -			if (zone.G >= minG) {
> -				zone.R = region.val.rSum / region.counted;
> -				zone.B = region.val.bSum / region.counted;
> -				zones.push_back(zone);
> +			if (zone.G < minG)
> +				continue;
> +			zone.R = region.val.rSum / region.counted;
> +			zone.B = region.val.bSum / region.counted;
> +			/* Factor in the ALSC applied colour shading correction if required. */
> +			const AlscStatus *alscStatus = globalMetadata.getLocked<AlscStatus>("alsc.status");
> +			if (stats->colourStatsPos == Statistics::ColourStatsPos::PreLsc && alscStatus) {
> +				zone.R *= alscStatus->r[i];
> +				zone.G *= alscStatus->g[i];
> +				zone.B *= alscStatus->b[i];
>  			}
> +			zones.push_back(zone);
>  		}
>  	}
>  }
> @@ -421,8 +432,8 @@ void Awb::prepareStats()
>  	 * LSC has already been applied to the stats in this pipeline, so stop
>  	 * any LSC compensation.  We also ignore config_.fast in this version.
>  	 */
> -	generateStats(zones_, statistics_->awbRegions, config_.minPixels,
> -		      config_.minG);
> +	generateStats(zones_, statistics_, config_.minPixels,
> +		      config_.minG, getGlobalMetadata());
>  	/*
>  	 * apply sensitivities, so values appear to come from our "canonical"
>  	 * sensor.
> --
> 2.34.1
>