[PATCH v2 14/17] ipa: rkisp1: Damp color temperature regulation

[Stefan Klug]

Damp the regulation of the color temperature with the same factor as the
gains.  Not damping the color temperature leads to visible flicker, as
the CCM changes too much.

Signed-off-by: Stefan Klug <stefan.klug at ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham at ideasonboard.com>

---

Changes in v2:
- Collected tags
---
 src/ipa/rkisp1/algorithms/awb.cpp | 3 +++
 src/ipa/rkisp1/algorithms/ccm.cpp | 4 ----
 2 files changed, 3 insertions(+), 4 deletions(-)

diff --git a/src/ipa/rkisp1/algorithms/awb.cpp b/src/ipa/rkisp1/algorithms/awb.cpp
index 286d9e3e2018..149c6aa59c8d 100644
--- a/src/ipa/rkisp1/algorithms/awb.cpp
+++ b/src/ipa/rkisp1/algorithms/awb.cpp
@@ -342,9 +342,12 @@ void Awb::process(IPAContext &context,
 
 	/* Filter the values to avoid oscillations. */
 	double speed = 0.2;
+	double ct = estimateCCT(rgbMeans);
+	ct = ct * speed + activeState.awb.automatic.temperatureK * (1 - speed);
 	awbResult.gains = awbResult.gains * speed +
 			  activeState.awb.automatic.gains * (1 - speed);
 
+	activeState.awb.automatic.temperatureK = static_cast<unsigned int>(ct);
 	activeState.awb.automatic.gains = awbResult.gains;
 
 	LOG(RkISP1Awb, Debug)
diff --git a/src/ipa/rkisp1/algorithms/ccm.cpp b/src/ipa/rkisp1/algorithms/ccm.cpp
index 303ac3dd2fe2..b7f32f0d5d8a 100644
--- a/src/ipa/rkisp1/algorithms/ccm.cpp
+++ b/src/ipa/rkisp1/algorithms/ccm.cpp
@@ -139,10 +139,6 @@ void Ccm::prepare(IPAContext &context, const uint32_t frame,
 	}
 
 	uint32_t ct = frameContext.awb.temperatureK;
-	/*
-	 * \todo The colour temperature will likely be noisy, add filtering to
-	 * avoid updating the CCM matrix all the time.
-	 */
 	if (frame > 0 && ct == ct_) {
 		frameContext.ccm.ccm = context.activeState.ccm.automatic;
 		return;
-- 
2.43.0