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

[Jean-Michel Hautbois]

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;
+
+	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;
-- 
2.32.0