[libcamera-devel] [PATCH v1 5/6] ipa: rkisp1: Introduce crosstalk correction

[Laurent Pinchart]

Hi Jean-Michel,

On Thu, Dec 02, 2021 at 07:04:09PM +0100, Jean-Michel Hautbois wrote:
> Introduce the color correction matrix for the RkISP1 based on a simple
> assumptions on the gains until we can tune the sensor properly.
> 
> Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois at ideasonboard.com>
> ---
>  src/ipa/rkisp1/algorithms/ctk.cpp     | 59 +++++++++++++++++++++++++++
>  src/ipa/rkisp1/algorithms/ctk.h       | 30 ++++++++++++++
>  src/ipa/rkisp1/algorithms/meson.build |  1 +
>  src/ipa/rkisp1/rkisp1.cpp             |  2 +
>  4 files changed, 92 insertions(+)
>  create mode 100644 src/ipa/rkisp1/algorithms/ctk.cpp
>  create mode 100644 src/ipa/rkisp1/algorithms/ctk.h
> 
> diff --git a/src/ipa/rkisp1/algorithms/ctk.cpp b/src/ipa/rkisp1/algorithms/ctk.cpp
> new file mode 100644
> index 000000000..81600e776
> --- /dev/null
> +++ b/src/ipa/rkisp1/algorithms/ctk.cpp
> @@ -0,0 +1,59 @@
> +/* SPDX-License-Identifier: LGPL-2.1-or-later */
> +/*
> + * Copyright (C) 2021, Ideas On Board
> + *
> + * ctk.cpp - RkISP1 Cross-Talk Correction control
> + */
> +
> +#include "ctk.h"
> +
> +/**
> + * \file ctk.h
> + */
> +
> +namespace libcamera {
> +
> +namespace ipa::rkisp1::algorithms {
> +
> +/**
> + * \class CrossTalkCorrection
> + * \brief RkISP1 Cross-Talk Correction control (color correction matrix)
> + *
> + * The crosstalk in image sensor is an effect when signal from a specific pixel
> + * is affected by its adjacent pixels. An image sensor can be considered as a
> + * linear system, with linear crosstalk existing only between horizontal and
> + * vertical neighboring pixels. This matrix should be calculated based on tuning
> + * but a first approximation can be obtained by using the grey-world gains and
> + * applying them to their respective channel.
> + */
> +
> +/**
> + * \copydoc libcamera::ipa::Algorithm::prepare
> + */
> +void CrossTalkCorrection::prepare([[maybe_unused]] IPAContext &context,
> +				  rkisp1_params_cfg *params)
> +{
> +	params->others.ctk_config.coeff[0][0] = 128 * context.frameContext.awb.gains.red;
> +	params->others.ctk_config.coeff[0][1] = 0;
> +	params->others.ctk_config.coeff[0][2] = 0;
> +
> +	params->others.ctk_config.coeff[1][0] = 0;
> +	params->others.ctk_config.coeff[1][1] = 128 * context.frameContext.awb.gains.green;
> +	params->others.ctk_config.coeff[1][2] = 0;
> +
> +	params->others.ctk_config.coeff[2][0] = 0;
> +	params->others.ctk_config.coeff[2][1] = 0;
> +	params->others.ctk_config.coeff[2][2] = 128 * context.frameContext.awb.gains.blue;

I don't get it, won't this essentially apply the AWB gains a second time
?

> +
> +	params->others.ctk_config.ct_offset[0] = 0;
> +	params->others.ctk_config.ct_offset[1] = 0;
> +	params->others.ctk_config.ct_offset[2] = 0;
> +
> +	params->module_en_update |= RKISP1_CIF_ISP_MODULE_CTK;
> +	params->module_ens |= RKISP1_CIF_ISP_MODULE_CTK;
> +	params->module_cfg_update |= RKISP1_CIF_ISP_MODULE_CTK;
> +}
> +
> +} /* namespace ipa::rkisp1::algorithms */
> +
> +} /* namespace libcamera */
> diff --git a/src/ipa/rkisp1/algorithms/ctk.h b/src/ipa/rkisp1/algorithms/ctk.h
> new file mode 100644
> index 000000000..c4d240e2d
> --- /dev/null
> +++ b/src/ipa/rkisp1/algorithms/ctk.h
> @@ -0,0 +1,30 @@
> +/* SPDX-License-Identifier: LGPL-2.1-or-later */
> +/*
> + * Copyright (C) 2021, Ideas On Board
> + *
> + * blc.h - RkISP1 Cross-Talk Correction control
> + */
> +
> +#pragma once
> +
> +#include <linux/rkisp1-config.h>
> +
> +#include "algorithm.h"
> +
> +namespace libcamera {
> +
> +struct IPACameraSensorInfo;
> +
> +namespace ipa::rkisp1::algorithms {
> +
> +class CrossTalkCorrection : public Algorithm
> +{
> +public:
> +	CrossTalkCorrection() = default;
> +	~CrossTalkCorrection() = default;
> +
> +	void prepare(IPAContext &context, rkisp1_params_cfg *params) override;
> +};
> +
> +} /* namespace ipa::rkisp1::algorithms */
> +} /* namespace libcamera */
> diff --git a/src/ipa/rkisp1/algorithms/meson.build b/src/ipa/rkisp1/algorithms/meson.build
> index faec0eb3e..482e88474 100644
> --- a/src/ipa/rkisp1/algorithms/meson.build
> +++ b/src/ipa/rkisp1/algorithms/meson.build
> @@ -4,5 +4,6 @@ rkisp1_ipa_algorithms = files([
>      'agc.cpp',
>      'awb.cpp',
>      'blc.cpp',
> +    'ctk.cpp',
>      'sdg.cpp',
>  ])
> diff --git a/src/ipa/rkisp1/rkisp1.cpp b/src/ipa/rkisp1/rkisp1.cpp
> index 979f28420..21a9d15b9 100644
> --- a/src/ipa/rkisp1/rkisp1.cpp
> +++ b/src/ipa/rkisp1/rkisp1.cpp
> @@ -29,6 +29,7 @@
>  #include "algorithms/algorithm.h"
>  #include "algorithms/awb.h"
>  #include "algorithms/blc.h"
> +#include "algorithms/ctk.h"
>  #include "algorithms/sdg.h"
>  #include "libipa/camera_sensor_helper.h"
>  
> @@ -130,6 +131,7 @@ int IPARkISP1::init(const IPASettings &settings, unsigned int hwRevision)
>  	algorithms_.push_back(std::make_unique<algorithms::Agc>());
>  	algorithms_.push_back(std::make_unique<algorithms::Awb>());
>  	algorithms_.push_back(std::make_unique<algorithms::BlackLevelCorrection>());
> +	algorithms_.push_back(std::make_unique<algorithms::CrossTalkCorrection>());
>  	algorithms_.push_back(std::make_unique<algorithms::SensorDeGamma>());
>  
>  	return 0;

-- 
Regards,

Laurent Pinchart