[libcamera-devel] [PATCH v4 10/14] ipa: ipu3: awb: Add support for color temperature

[Umang Jain]

Hi JM

Thank you for the patch

On 11/11/21 7:39 PM, Jean-Michel Hautbois wrote:
> The AWB estimates the color temperature, but it is not used at all. It
> can be useful for debug purpose at least, but also for lux estimation
> later, to be able to know the temperature estimated for a given frame.
>
> Add a new member to the IPAFrameContext::awb for this purpose, and
> update the value in AWB.
>
> Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois at ideasonboard.com>
> Reviewed-by: Kieran Bingham <kieran.bingham at ideasonboard.com>


Reviewed-by: Umang Jain <umang.jain at ideasonboard.com>

> ---
>   src/ipa/ipu3/algorithms/awb.cpp | 1 +
>   src/ipa/ipu3/ipa_context.cpp    | 3 +++
>   src/ipa/ipu3/ipa_context.h      | 2 ++
>   3 files changed, 6 insertions(+)
>
> diff --git a/src/ipa/ipu3/algorithms/awb.cpp b/src/ipa/ipu3/algorithms/awb.cpp
> index a4114659..c7bcb20e 100644
> --- a/src/ipa/ipu3/algorithms/awb.cpp
> +++ b/src/ipa/ipu3/algorithms/awb.cpp
> @@ -385,6 +385,7 @@ void Awb::process(IPAContext &context, const ipu3_uapi_stats_3a *stats)
>   	context.frameContext.awb.gains.blue = asyncResults_.blueGain;
>   	context.frameContext.awb.gains.green = asyncResults_.greenGain;
>   	context.frameContext.awb.gains.red = asyncResults_.redGain;
> +	context.frameContext.awb.temperatureK = asyncResults_.temperatureK;
>   }
>   
>   constexpr uint16_t Awb::threshold(float value)
> diff --git a/src/ipa/ipu3/ipa_context.cpp b/src/ipa/ipu3/ipa_context.cpp
> index a7ff957d..99caf9ad 100644
> --- a/src/ipa/ipu3/ipa_context.cpp
> +++ b/src/ipa/ipu3/ipa_context.cpp
> @@ -117,6 +117,9 @@ namespace libcamera::ipa::ipu3 {
>    *
>    * \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/ipu3/ipa_context.h b/src/ipa/ipu3/ipa_context.h
> index a5a19800..fd97e240 100644
> --- a/src/ipa/ipu3/ipa_context.h
> +++ b/src/ipa/ipu3/ipa_context.h
> @@ -45,6 +45,8 @@ struct IPAFrameContext {
>   			double green;
>   			double blue;
>   		} gains;
> +
> +		double temperatureK;
>   	} awb;
>   
>   	struct {