[v3,14/16] ipa: rkisp1: Damp color temperature regulation

23130 diff mbox series

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@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>

---

Changes in v2:
- Collected tags

Changes in v3:
- Dropped incorrect call to estimateCCT()
---
 src/ipa/rkisp1/algorithms/awb.cpp | 5 +++--
 src/ipa/rkisp1/algorithms/ccm.cpp | 4 ----
 2 files changed, 3 insertions(+), 6 deletions(-)

On Thu, Apr 03, 2025 at 05:49:19PM +0200, Stefan Klug wrote:
> 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@ideasonboard.com>
> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>

Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>

> 
> ---
> 
> Changes in v2:
> - Collected tags
> 
> Changes in v3:
> - Dropped incorrect call to estimateCCT()
> ---
>  src/ipa/rkisp1/algorithms/awb.cpp | 5 +++--
>  src/ipa/rkisp1/algorithms/ccm.cpp | 4 ----
>  2 files changed, 3 insertions(+), 6 deletions(-)
> 
> diff --git a/src/ipa/rkisp1/algorithms/awb.cpp b/src/ipa/rkisp1/algorithms/awb.cpp
> index f5415a0bb99d..47b29725af51 100644
> --- a/src/ipa/rkisp1/algorithms/awb.cpp
> +++ b/src/ipa/rkisp1/algorithms/awb.cpp
> @@ -317,8 +317,6 @@ void Awb::process(IPAContext &context,
>  	RkISP1AwbStats awbStats{ rgbMeans };
>  	AwbResult awbResult = awbAlgo_->calculateAwb(awbStats, frameContext.lux.lux);
>  
> -	activeState.awb.automatic.temperatureK = awbResult.colourTemperature;
> -
>  	/*
>  	 * Clamp the gain values to the hardware, which expresses gains as Q2.8
>  	 * unsigned integer values. Set the minimum just above zero to avoid
> @@ -329,9 +327,12 @@ void Awb::process(IPAContext &context,
>  
>  	/* Filter the values to avoid oscillations. */
>  	double speed = 0.2;
> +	double ct = awbResult.colourTemperature;
> +	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 3a96a5427bc6..de2b6fe775aa 100644
> --- a/src/ipa/rkisp1/algorithms/ccm.cpp
> +++ b/src/ipa/rkisp1/algorithms/ccm.cpp
> @@ -142,10 +142,6 @@ 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
>