12 files changed, 815 insertions, 0 deletions
diff --git a/src/ipa/simple/algorithms/agc.cpp b/src/ipa/simple/algorithms/agc.cpp
new file mode 100644
index 00000000..c46bb0eb
--- /dev/null
+++ b/src/ipa/simple/algorithms/agc.cpp
@@ -0,0 +1,146 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2024, Red Hat Inc.
+ *
+ * Exposure and gain
+ */
+
+#include "agc.h"
+
+#include <stdint.h>
+
+#include <libcamera/base/log.h>
+
+#include "control_ids.h"
+
+namespace libcamera {
+
+LOG_DEFINE_CATEGORY(IPASoftExposure)
+
+namespace ipa::soft::algorithms {
+
+/*
+ * The number of bins to use for the optimal exposure calculations.
+ */
+static constexpr unsigned int kExposureBinsCount = 5;
+
+/*
+ * The exposure is optimal when the mean sample value of the histogram is
+ * in the middle of the range.
+ */
+static constexpr float kExposureOptimal = kExposureBinsCount / 2.0;
+
+/*
+ * This implements the hysteresis for the exposure adjustment.
+ * It is small enough to have the exposure close to the optimal, and is big
+ * enough to prevent the exposure from wobbling around the optimal value.
+ */
+static constexpr float kExposureSatisfactory = 0.2;
+
+Agc::Agc()
+{
+}
+
+void Agc::updateExposure(IPAContext &context, IPAFrameContext &frameContext, double exposureMSV)
+{
+	/*
+	 * kExpDenominator of 10 gives ~10% increment/decrement;
+	 * kExpDenominator of 5 - about ~20%
+	 */
+	static constexpr uint8_t kExpDenominator = 10;
+	static constexpr uint8_t kExpNumeratorUp = kExpDenominator + 1;
+	static constexpr uint8_t kExpNumeratorDown = kExpDenominator - 1;
+
+	double next;
+	int32_t &exposure = frameContext.sensor.exposure;
+	double &again = frameContext.sensor.gain;
+
+	if (exposureMSV < kExposureOptimal - kExposureSatisfactory) {
+		next = exposure * kExpNumeratorUp / kExpDenominator;
+		if (next - exposure < 1)
+			exposure += 1;
+		else
+			exposure = next;
+		if (exposure >= context.configuration.agc.exposureMax) {
+			next = again * kExpNumeratorUp / kExpDenominator;
+			if (next - again < context.configuration.agc.againMinStep)
+				again += context.configuration.agc.againMinStep;
+			else
+				again = next;
+		}
+	}
+
+	if (exposureMSV > kExposureOptimal + kExposureSatisfactory) {
+		if (exposure == context.configuration.agc.exposureMax &&
+		    again > context.configuration.agc.againMin) {
+			next = again * kExpNumeratorDown / kExpDenominator;
+			if (again - next < context.configuration.agc.againMinStep)
+				again -= context.configuration.agc.againMinStep;
+			else
+				again = next;
+		} else {
+			next = exposure * kExpNumeratorDown / kExpDenominator;
+			if (exposure - next < 1)
+				exposure -= 1;
+			else
+				exposure = next;
+		}
+	}
+
+	exposure = std::clamp(exposure, context.configuration.agc.exposureMin,
+			      context.configuration.agc.exposureMax);
+	again = std::clamp(again, context.configuration.agc.againMin,
+			   context.configuration.agc.againMax);
+
+	LOG(IPASoftExposure, Debug)
+		<< "exposureMSV " << exposureMSV
+		<< " exp " << exposure << " again " << again;
+}
+
+void Agc::process(IPAContext &context,
+		  [[maybe_unused]] const uint32_t frame,
+		  IPAFrameContext &frameContext,
+		  const SwIspStats *stats,
+		  ControlList &metadata)
+{
+	utils::Duration exposureTime =
+		context.configuration.agc.lineDuration * frameContext.sensor.exposure;
+	metadata.set(controls::ExposureTime, exposureTime.get<std::micro>());
+	metadata.set(controls::AnalogueGain, frameContext.sensor.gain);
+
+	/*
+	 * Calculate Mean Sample Value (MSV) according to formula from:
+	 * https://www.araa.asn.au/acra/acra2007/papers/paper84final.pdf
+	 */
+	const auto &histogram = stats->yHistogram;
+	const unsigned int blackLevelHistIdx =
+		context.activeState.blc.level / (256 / SwIspStats::kYHistogramSize);
+	const unsigned int histogramSize =
+		SwIspStats::kYHistogramSize - blackLevelHistIdx;
+	const unsigned int yHistValsPerBin = histogramSize / kExposureBinsCount;
+	const unsigned int yHistValsPerBinMod =
+		histogramSize / (histogramSize % kExposureBinsCount + 1);
+	int exposureBins[kExposureBinsCount] = {};
+	unsigned int denom = 0;
+	unsigned int num = 0;
+
+	for (unsigned int i = 0; i < histogramSize; i++) {
+		unsigned int idx = (i - (i / yHistValsPerBinMod)) / yHistValsPerBin;
+		exposureBins[idx] += histogram[blackLevelHistIdx + i];
+	}
+
+	for (unsigned int i = 0; i < kExposureBinsCount; i++) {
+		LOG(IPASoftExposure, Debug) << i << ": " << exposureBins[i];
+		denom += exposureBins[i];
+		num += exposureBins[i] * (i + 1);
+	}
+
+	float exposureMSV = (denom == 0 ? 0 : static_cast<float>(num) / denom);
+	updateExposure(context, frameContext, exposureMSV);
+}
+
+REGISTER_IPA_ALGORITHM(Agc, "Agc")
+
+} /* namespace ipa::soft::algorithms */
+
+} /* namespace libcamera */
diff --git a/src/ipa/simple/algorithms/agc.h b/src/ipa/simple/algorithms/agc.h
new file mode 100644
index 00000000..112d9f5a
--- /dev/null
+++ b/src/ipa/simple/algorithms/agc.h
@@ -0,0 +1,33 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2024, Red Hat Inc.
+ *
+ * Exposure and gain
+ */
+
+#pragma once
+
+#include "algorithm.h"
+
+namespace libcamera {
+
+namespace ipa::soft::algorithms {
+
+class Agc : public Algorithm
+{
+public:
+	Agc();
+	~Agc() = default;
+
+	void process(IPAContext &context, const uint32_t frame,
+		     IPAFrameContext &frameContext,
+		     const SwIspStats *stats,
+		     ControlList &metadata) override;
+
+private:
+	void updateExposure(IPAContext &context, IPAFrameContext &frameContext, double exposureMSV);
+};
+
+} /* namespace ipa::soft::algorithms */
+
+} /* namespace libcamera */
diff --git a/src/ipa/simple/algorithms/algorithm.h b/src/ipa/simple/algorithms/algorithm.h
new file mode 100644
index 00000000..41f63170
--- /dev/null
+++ b/src/ipa/simple/algorithms/algorithm.h
@@ -0,0 +1,22 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2024 Red Hat, Inc.
+ *
+ * Software ISP control algorithm interface
+ */
+
+#pragma once
+
+#include <libipa/algorithm.h>
+
+#include "module.h"
+
+namespace libcamera {
+
+namespace ipa::soft {
+
+using Algorithm = libcamera::ipa::Algorithm<Module>;
+
+} /* namespace ipa::soft */
+
+} /* namespace libcamera */
diff --git a/src/ipa/simple/algorithms/awb.cpp b/src/ipa/simple/algorithms/awb.cpp
new file mode 100644
index 00000000..cf567e89
--- /dev/null
+++ b/src/ipa/simple/algorithms/awb.cpp
@@ -0,0 +1,100 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2024, Red Hat Inc.
+ *
+ * Auto white balance
+ */
+
+#include "awb.h"
+
+#include <numeric>
+#include <stdint.h>
+
+#include <libcamera/base/log.h>
+
+#include <libcamera/control_ids.h>
+
+#include "libipa/colours.h"
+#include "simple/ipa_context.h"
+
+#include "control_ids.h"
+
+namespace libcamera {
+
+LOG_DEFINE_CATEGORY(IPASoftAwb)
+
+namespace ipa::soft::algorithms {
+
+int Awb::configure(IPAContext &context,
+		   [[maybe_unused]] const IPAConfigInfo &configInfo)
+{
+	auto &gains = context.activeState.awb.gains;
+	gains = { { 1.0, 1.0, 1.0 } };
+
+	return 0;
+}
+
+void Awb::prepare(IPAContext &context,
+		  [[maybe_unused]] const uint32_t frame,
+		  IPAFrameContext &frameContext,
+		  [[maybe_unused]] DebayerParams *params)
+{
+	auto &gains = context.activeState.awb.gains;
+	/* Just report, the gains are applied in LUT algorithm. */
+	frameContext.gains.red = gains.r();
+	frameContext.gains.blue = gains.b();
+}
+
+void Awb::process(IPAContext &context,
+		  [[maybe_unused]] const uint32_t frame,
+		  IPAFrameContext &frameContext,
+		  const SwIspStats *stats,
+		  ControlList &metadata)
+{
+	const SwIspStats::Histogram &histogram = stats->yHistogram;
+	const uint8_t blackLevel = context.activeState.blc.level;
+
+	const float maxGain = 1024.0;
+	const float mdGains[] = {
+		static_cast<float>(frameContext.gains.red / maxGain),
+		static_cast<float>(frameContext.gains.blue / maxGain)
+	};
+	metadata.set(controls::ColourGains, mdGains);
+
+	/*
+	 * Black level must be subtracted to get the correct AWB ratios, they
+	 * would be off if they were computed from the whole brightness range
+	 * rather than from the sensor range.
+	 */
+	const uint64_t nPixels = std::accumulate(
+		histogram.begin(), histogram.end(), 0);
+	const uint64_t offset = blackLevel * nPixels;
+	const uint64_t sumR = stats->sumR_ - offset / 4;
+	const uint64_t sumG = stats->sumG_ - offset / 2;
+	const uint64_t sumB = stats->sumB_ - offset / 4;
+
+	/*
+	 * Calculate red and blue gains for AWB.
+	 * Clamp max gain at 4.0, this also avoids 0 division.
+	 */
+	auto &gains = context.activeState.awb.gains;
+	gains = { {
+		sumR <= sumG / 4 ? 4.0f : static_cast<float>(sumG) / sumR,
+		1.0,
+		sumB <= sumG / 4 ? 4.0f : static_cast<float>(sumG) / sumB,
+	} };
+
+	RGB<double> rgbGains{ { 1 / gains.r(), 1 / gains.g(), 1 / gains.b() } };
+	context.activeState.awb.temperatureK = estimateCCT(rgbGains);
+	metadata.set(controls::ColourTemperature, context.activeState.awb.temperatureK);
+
+	LOG(IPASoftAwb, Debug)
+		<< "gain R/B: " << gains << "; temperature: "
+		<< context.activeState.awb.temperatureK;
+}
+
+REGISTER_IPA_ALGORITHM(Awb, "Awb")
+
+} /* namespace ipa::soft::algorithms */
+
+} /* namespace libcamera */
diff --git a/src/ipa/simple/algorithms/awb.h b/src/ipa/simple/algorithms/awb.h
new file mode 100644
index 00000000..ad993f39
--- /dev/null
+++ b/src/ipa/simple/algorithms/awb.h
@@ -0,0 +1,36 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2024-2025 Red Hat Inc.
+ *
+ * Auto white balance
+ */
+
+#pragma once
+
+#include "algorithm.h"
+
+namespace libcamera {
+
+namespace ipa::soft::algorithms {
+
+class Awb : public Algorithm
+{
+public:
+	Awb() = default;
+	~Awb() = default;
+
+	int configure(IPAContext &context, const IPAConfigInfo &configInfo) override;
+	void prepare(IPAContext &context,
+		     const uint32_t frame,
+		     IPAFrameContext &frameContext,
+		     DebayerParams *params) override;
+	void process(IPAContext &context,
+		     const uint32_t frame,
+		     IPAFrameContext &frameContext,
+		     const SwIspStats *stats,
+		     ControlList &metadata) override;
+};
+
+} /* namespace ipa::soft::algorithms */
+
+} /* namespace libcamera */
diff --git a/src/ipa/simple/algorithms/blc.cpp b/src/ipa/simple/algorithms/blc.cpp
new file mode 100644
index 00000000..8c1e9ed0
--- /dev/null
+++ b/src/ipa/simple/algorithms/blc.cpp
@@ -0,0 +1,107 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2024-2025, Red Hat Inc.
+ *
+ * Black level handling
+ */
+
+#include "blc.h"
+
+#include <numeric>
+
+#include <libcamera/base/log.h>
+
+#include "control_ids.h"
+
+namespace libcamera {
+
+namespace ipa::soft::algorithms {
+
+LOG_DEFINE_CATEGORY(IPASoftBL)
+
+BlackLevel::BlackLevel()
+{
+}
+
+int BlackLevel::init([[maybe_unused]] IPAContext &context,
+		     const YamlObject &tuningData)
+{
+	auto blackLevel = tuningData["blackLevel"].get<int16_t>();
+	if (blackLevel.has_value()) {
+		/*
+		 * Convert 16 bit values from the tuning file to 8 bit black
+		 * level for the SoftISP.
+		 */
+		definedLevel_ = blackLevel.value() >> 8;
+	}
+	return 0;
+}
+
+int BlackLevel::configure(IPAContext &context,
+			  [[maybe_unused]] const IPAConfigInfo &configInfo)
+{
+	if (definedLevel_.has_value())
+		context.configuration.black.level = definedLevel_;
+	context.activeState.blc.level =
+		context.configuration.black.level.value_or(255);
+	return 0;
+}
+
+void BlackLevel::process(IPAContext &context,
+			 [[maybe_unused]] const uint32_t frame,
+			 IPAFrameContext &frameContext,
+			 const SwIspStats *stats,
+			 ControlList &metadata)
+{
+	/* Assign each of the R G G B channels as the same black level. */
+	const int32_t blackLevel = context.activeState.blc.level * 256;
+	const int32_t blackLevels[] = {
+		blackLevel, blackLevel, blackLevel, blackLevel
+	};
+	metadata.set(controls::SensorBlackLevels, blackLevels);
+
+	if (context.configuration.black.level.has_value())
+		return;
+
+	if (frameContext.sensor.exposure == context.activeState.blc.lastExposure &&
+	    frameContext.sensor.gain == context.activeState.blc.lastGain) {
+		return;
+	}
+
+	const SwIspStats::Histogram &histogram = stats->yHistogram;
+
+	/*
+	 * The constant is selected to be "good enough", not overly
+	 * conservative or aggressive. There is no magic about the given value.
+	 */
+	constexpr float ignoredPercentage = 0.02;
+	const unsigned int total =
+		std::accumulate(begin(histogram), end(histogram), 0);
+	const unsigned int pixelThreshold = ignoredPercentage * total;
+	const unsigned int histogramRatio = 256 / SwIspStats::kYHistogramSize;
+	const unsigned int currentBlackIdx =
+		context.activeState.blc.level / histogramRatio;
+
+	for (unsigned int i = 0, seen = 0;
+	     i < currentBlackIdx && i < SwIspStats::kYHistogramSize;
+	     i++) {
+		seen += histogram[i];
+		if (seen >= pixelThreshold) {
+			context.activeState.blc.level = i * histogramRatio;
+			context.activeState.blc.lastExposure = frameContext.sensor.exposure;
+			context.activeState.blc.lastGain = frameContext.sensor.gain;
+			LOG(IPASoftBL, Debug)
+				<< "Auto-set black level: "
+				<< i << "/" << SwIspStats::kYHistogramSize
+				<< " (" << 100 * (seen - histogram[i]) / total << "% below, "
+				<< 100 * seen / total << "% at or below)";
+			break;
+		}
+	};
+}
+
+REGISTER_IPA_ALGORITHM(BlackLevel, "BlackLevel")
+
+} /* namespace ipa::soft::algorithms */
+
+} /* namespace libcamera */
diff --git a/src/ipa/simple/algorithms/blc.h b/src/ipa/simple/algorithms/blc.h
new file mode 100644
index 00000000..db9e6d63
--- /dev/null
+++ b/src/ipa/simple/algorithms/blc.h
@@ -0,0 +1,38 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2024, Red Hat Inc.
+ *
+ * Black level handling
+ */
+
+#pragma once
+
+#include <optional>
+#include <stdint.h>
+
+#include "algorithm.h"
+
+namespace libcamera {
+
+namespace ipa::soft::algorithms {
+
+class BlackLevel : public Algorithm
+{
+public:
+	BlackLevel();
+	~BlackLevel() = default;
+
+	int init(IPAContext &context, const YamlObject &tuningData) override;
+	int configure(IPAContext &context, const IPAConfigInfo &configInfo) override;
+	void process(IPAContext &context, const uint32_t frame,
+		     IPAFrameContext &frameContext,
+		     const SwIspStats *stats,
+		     ControlList &metadata) override;
+
+private:
+	std::optional<uint8_t> definedLevel_;
+};
+
+} /* namespace ipa::soft::algorithms */
+
+} /* namespace libcamera */
diff --git a/src/ipa/simple/algorithms/ccm.cpp b/src/ipa/simple/algorithms/ccm.cpp
new file mode 100644
index 00000000..d5ba928d
--- /dev/null
+++ b/src/ipa/simple/algorithms/ccm.cpp
@@ -0,0 +1,76 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2024, Ideas On Board
+ * Copyright (C) 2024-2025, Red Hat Inc.
+ *
+ * Color correction matrix
+ */
+
+#include "ccm.h"
+
+#include <libcamera/base/log.h>
+#include <libcamera/base/utils.h>
+
+#include <libcamera/control_ids.h>
+
+namespace {
+
+constexpr unsigned int kTemperatureThreshold = 100;
+
+}
+
+namespace libcamera {
+
+namespace ipa::soft::algorithms {
+
+LOG_DEFINE_CATEGORY(IPASoftCcm)
+
+int Ccm::init([[maybe_unused]] IPAContext &context, const YamlObject &tuningData)
+{
+	int ret = ccm_.readYaml(tuningData["ccms"], "ct", "ccm");
+	if (ret < 0) {
+		LOG(IPASoftCcm, Error)
+			<< "Failed to parse 'ccm' parameter from tuning file.";
+		return ret;
+	}
+
+	context.ccmEnabled = true;
+
+	return 0;
+}
+
+void Ccm::prepare(IPAContext &context, const uint32_t frame,
+		  IPAFrameContext &frameContext, [[maybe_unused]] DebayerParams *params)
+{
+	const unsigned int ct = context.activeState.awb.temperatureK;
+
+	/* Change CCM only on bigger temperature changes. */
+	if (frame > 0 &&
+	    utils::abs_diff(ct, lastCt_) < kTemperatureThreshold) {
+		frameContext.ccm.ccm = context.activeState.ccm.ccm;
+		context.activeState.ccm.changed = false;
+		return;
+	}
+
+	lastCt_ = ct;
+	Matrix<float, 3, 3> ccm = ccm_.getInterpolated(ct);
+
+	context.activeState.ccm.ccm = ccm;
+	frameContext.ccm.ccm = ccm;
+	context.activeState.ccm.changed = true;
+}
+
+void Ccm::process([[maybe_unused]] IPAContext &context,
+		  [[maybe_unused]] const uint32_t frame,
+		  IPAFrameContext &frameContext,
+		  [[maybe_unused]] const SwIspStats *stats,
+		  ControlList &metadata)
+{
+	metadata.set(controls::ColourCorrectionMatrix, frameContext.ccm.ccm.data());
+}
+
+REGISTER_IPA_ALGORITHM(Ccm, "Ccm")
+
+} /* namespace ipa::soft::algorithms */
+
+} /* namespace libcamera */
diff --git a/src/ipa/simple/algorithms/ccm.h b/src/ipa/simple/algorithms/ccm.h
new file mode 100644
index 00000000..f4e2b85b
--- /dev/null
+++ b/src/ipa/simple/algorithms/ccm.h
@@ -0,0 +1,43 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2024-2025, Red Hat Inc.
+ *
+ * Color correction matrix
+ */
+
+#pragma once
+
+#include "libcamera/internal/matrix.h"
+
+#include <libipa/interpolator.h>
+
+#include "algorithm.h"
+
+namespace libcamera {
+
+namespace ipa::soft::algorithms {
+
+class Ccm : public Algorithm
+{
+public:
+	Ccm() = default;
+	~Ccm() = default;
+
+	int init(IPAContext &context, const YamlObject &tuningData) override;
+	void prepare(IPAContext &context,
+		     const uint32_t frame,
+		     IPAFrameContext &frameContext,
+		     DebayerParams *params) override;
+	void process(IPAContext &context, const uint32_t frame,
+		     IPAFrameContext &frameContext,
+		     const SwIspStats *stats,
+		     ControlList &metadata) override;
+
+private:
+	unsigned int lastCt_;
+	Interpolator<Matrix<float, 3, 3>> ccm_;
+};
+
+} /* namespace ipa::soft::algorithms */
+
+} /* namespace libcamera */
diff --git a/src/ipa/simple/algorithms/lut.cpp b/src/ipa/simple/algorithms/lut.cpp
new file mode 100644
index 00000000..d1d5f727
--- /dev/null
+++ b/src/ipa/simple/algorithms/lut.cpp
@@ -0,0 +1,159 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2024-2025, Red Hat Inc.
+ *
+ * Color lookup tables construction
+ */
+
+#include "lut.h"
+
+#include <algorithm>
+#include <cmath>
+#include <optional>
+#include <stdint.h>
+
+#include <libcamera/base/log.h>
+
+#include <libcamera/control_ids.h>
+
+#include "simple/ipa_context.h"
+
+namespace libcamera {
+
+LOG_DEFINE_CATEGORY(IPASoftLut)
+
+namespace ipa::soft::algorithms {
+
+int Lut::init(IPAContext &context,
+	      [[maybe_unused]] const YamlObject &tuningData)
+{
+	context.ctrlMap[&controls::Contrast] = ControlInfo(0.0f, 2.0f, 1.0f);
+	return 0;
+}
+
+int Lut::configure(IPAContext &context,
+		   [[maybe_unused]] const IPAConfigInfo &configInfo)
+{
+	/* Gamma value is fixed */
+	context.configuration.gamma = 0.5;
+	context.activeState.knobs.contrast = std::optional<double>();
+	updateGammaTable(context);
+
+	return 0;
+}
+
+void Lut::queueRequest(typename Module::Context &context,
+		       [[maybe_unused]] const uint32_t frame,
+		       [[maybe_unused]] typename Module::FrameContext &frameContext,
+		       const ControlList &controls)
+{
+	const auto &contrast = controls.get(controls::Contrast);
+	if (contrast.has_value()) {
+		context.activeState.knobs.contrast = contrast;
+		LOG(IPASoftLut, Debug) << "Setting contrast to " << contrast.value();
+	}
+}
+
+void Lut::updateGammaTable(IPAContext &context)
+{
+	auto &gammaTable = context.activeState.gamma.gammaTable;
+	const auto blackLevel = context.activeState.blc.level;
+	const unsigned int blackIndex = blackLevel * gammaTable.size() / 256;
+	const auto contrast = context.activeState.knobs.contrast.value_or(1.0);
+
+	std::fill(gammaTable.begin(), gammaTable.begin() + blackIndex, 0);
+	const float divisor = gammaTable.size() - blackIndex - 1.0;
+	for (unsigned int i = blackIndex; i < gammaTable.size(); i++) {
+		double normalized = (i - blackIndex) / divisor;
+		/* Convert 0..2 to 0..infinity; avoid actual inifinity at tan(pi/2) */
+		double contrastExp = tan(std::clamp(contrast * M_PI_4, 0.0, M_PI_2 - 0.00001));
+		/* Apply simple S-curve */
+		if (normalized < 0.5)
+			normalized = 0.5 * std::pow(normalized / 0.5, contrastExp);
+		else
+			normalized = 1.0 - 0.5 * std::pow((1.0 - normalized) / 0.5, contrastExp);
+		gammaTable[i] = UINT8_MAX *
+				std::pow(normalized, context.configuration.gamma);
+	}
+
+	context.activeState.gamma.blackLevel = blackLevel;
+	context.activeState.gamma.contrast = contrast;
+}
+
+int16_t Lut::ccmValue(unsigned int i, float ccm) const
+{
+	return std::round(i * ccm);
+}
+
+void Lut::prepare(IPAContext &context,
+		  [[maybe_unused]] const uint32_t frame,
+		  IPAFrameContext &frameContext,
+		  DebayerParams *params)
+{
+	frameContext.contrast = context.activeState.knobs.contrast;
+
+	/*
+	 * Update the gamma table if needed. This means if black level changes
+	 * and since the black level gets updated only if a lower value is
+	 * observed, it's not permanently prone to minor fluctuations or
+	 * rounding errors.
+	 */
+	const bool gammaUpdateNeeded =
+		context.activeState.gamma.blackLevel != context.activeState.blc.level ||
+		context.activeState.gamma.contrast != context.activeState.knobs.contrast;
+	if (gammaUpdateNeeded)
+		updateGammaTable(context);
+
+	auto &gains = context.activeState.awb.gains;
+	auto &gammaTable = context.activeState.gamma.gammaTable;
+	const unsigned int gammaTableSize = gammaTable.size();
+	const double div = static_cast<double>(DebayerParams::kRGBLookupSize) /
+			   gammaTableSize;
+
+	if (!context.ccmEnabled) {
+		for (unsigned int i = 0; i < DebayerParams::kRGBLookupSize; i++) {
+			/* Apply gamma after gain! */
+			const RGB<float> lutGains = (gains * i / div).min(gammaTableSize - 1);
+			params->red[i] = gammaTable[static_cast<unsigned int>(lutGains.r())];
+			params->green[i] = gammaTable[static_cast<unsigned int>(lutGains.g())];
+			params->blue[i] = gammaTable[static_cast<unsigned int>(lutGains.b())];
+		}
+	} else if (context.activeState.ccm.changed || gammaUpdateNeeded) {
+		Matrix<float, 3, 3> gainCcm = { { gains.r(), 0, 0,
+						  0, gains.g(), 0,
+						  0, 0, gains.b() } };
+		auto ccm = context.activeState.ccm.ccm * gainCcm;
+		auto &red = params->redCcm;
+		auto &green = params->greenCcm;
+		auto &blue = params->blueCcm;
+		for (unsigned int i = 0; i < DebayerParams::kRGBLookupSize; i++) {
+			red[i].r = ccmValue(i, ccm[0][0]);
+			red[i].g = ccmValue(i, ccm[1][0]);
+			red[i].b = ccmValue(i, ccm[2][0]);
+			green[i].r = ccmValue(i, ccm[0][1]);
+			green[i].g = ccmValue(i, ccm[1][1]);
+			green[i].b = ccmValue(i, ccm[2][1]);
+			blue[i].r = ccmValue(i, ccm[0][2]);
+			blue[i].g = ccmValue(i, ccm[1][2]);
+			blue[i].b = ccmValue(i, ccm[2][2]);
+			params->gammaLut[i] = gammaTable[i / div];
+		}
+	}
+}
+
+void Lut::process([[maybe_unused]] IPAContext &context,
+		  [[maybe_unused]] const uint32_t frame,
+		  [[maybe_unused]] IPAFrameContext &frameContext,
+		  [[maybe_unused]] const SwIspStats *stats,
+		  ControlList &metadata)
+{
+	const auto &contrast = frameContext.contrast;
+	if (contrast)
+		metadata.set(controls::Contrast, contrast.value());
+}
+
+REGISTER_IPA_ALGORITHM(Lut, "Lut")
+
+} /* namespace ipa::soft::algorithms */
+
+} /* namespace libcamera */
diff --git a/src/ipa/simple/algorithms/lut.h b/src/ipa/simple/algorithms/lut.h
new file mode 100644
index 00000000..ba8b9021
--- /dev/null
+++ b/src/ipa/simple/algorithms/lut.h
@@ -0,0 +1,46 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2024, Red Hat Inc.
+ *
+ * Color lookup tables construction
+ */
+
+#pragma once
+
+#include "algorithm.h"
+
+namespace libcamera {
+
+namespace ipa::soft::algorithms {
+
+class Lut : public Algorithm
+{
+public:
+	Lut() = default;
+	~Lut() = default;
+
+	int init(IPAContext &context, const YamlObject &tuningData) override;
+	int configure(IPAContext &context, const IPAConfigInfo &configInfo) override;
+	void queueRequest(typename Module::Context &context,
+			  const uint32_t frame,
+			  typename Module::FrameContext &frameContext,
+			  const ControlList &controls)
+		override;
+	void prepare(IPAContext &context,
+		     const uint32_t frame,
+		     IPAFrameContext &frameContext,
+		     DebayerParams *params) override;
+	void process(IPAContext &context,
+		     const uint32_t frame,
+		     IPAFrameContext &frameContext,
+		     const SwIspStats *stats,
+		     ControlList &metadata) override;
+
+private:
+	void updateGammaTable(IPAContext &context);
+	int16_t ccmValue(unsigned int i, float ccm) const;
+};
+
+} /* namespace ipa::soft::algorithms */
+
+} /* namespace libcamera */
diff --git a/src/ipa/simple/algorithms/meson.build b/src/ipa/simple/algorithms/meson.build
new file mode 100644
index 00000000..2d0adb05
--- /dev/null
+++ b/src/ipa/simple/algorithms/meson.build
@@ -0,0 +1,9 @@
+# SPDX-License-Identifier: CC0-1.0
+
+soft_simple_ipa_algorithms = files([
+    'awb.cpp',
+    'agc.cpp',
+    'blc.cpp',
+    'ccm.cpp',
+    'lut.cpp',
+])