ipa: ipu3: awb: Correct the relevant zones proportion

The algorithm uses the statistics of a cell only if there is not too
much saturated pixels in it. The grey world algorithm works fine when
there are a limited number of outliers.
Consider a valid zone to be at least 80% of unsaturated cells in it.
This value could very well be configurable, and make the algorithm more
or less tolerant.

While at it, implement it in a configure() call as it will not change
during execution, and cache the cellsPerZone values estimated with
std::round as we are using cmath.

Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

1 files changed, 5 insertions, 0 deletions

diff --git a/src/ipa/ipu3/algorithms/awb.h b/src/ipa/ipu3/algorithms/awb.h
index 3385ebe7..681d8c2b 100644
--- a/src/ipa/ipu3/algorithms/awb.h
+++ b/src/ipa/ipu3/algorithms/awb.h
@@ -48,6 +48,7 @@ public:
 	Awb();
 	~Awb();
 
+	int configure(IPAContext &context, const IPAConfigInfo &configInfo) override;
 	void prepare(IPAContext &context, ipu3_uapi_params *params) override;
 	void process(IPAContext &context, const ipu3_uapi_stats_3a *stats) override;
 
@@ -85,6 +86,10 @@ private:
 	std::vector<RGB> zones_;
 	Accumulator awbStats_[kAwbStatsSizeX * kAwbStatsSizeY];
 	AwbStatus asyncResults_;
+
+	uint32_t cellsPerZoneX_;
+	uint32_t cellsPerZoneY_;
+	uint32_t cellsPerZoneThreshold_;
 };
 
 } /* namespace ipa::ipu3::algorithms */