[PATCH v3 3/3] ipa: rkisp1: Add GammaOutCorrection algorithm
Stefan Klug
stefan.klug at ideasonboard.com
Mon Jun 3 16:06:30 CEST 2024
Add a gamma algorithm for the rkisp1. It defaults to a gamma of 2.2 which
closely resembles sRGB. No seperate sRGB mode was implemented because the pwl
that models the gamma curve is so coarse that there is basically no difference
between srgb and gamma=2.2. The default can be overridden within the tuning
file or set at runtime using the gamma control.
The gamma algorithm is not enabled by default. This will be done in future
tuning file updates.
Signed-off-by: Stefan Klug <stefan.klug at ideasonboard.com>
---
v2 -> v3:
- Squashed with patch 1/4 from previous series
- Renamed from Gamma to GammaOutCorrection
- Read default gamma value from tuning file
- Some stylistic fixes from review
src/ipa/rkisp1/algorithms/goc.cpp | 161 ++++++++++++++++++++++++++
src/ipa/rkisp1/algorithms/goc.h | 48 ++++++++
src/ipa/rkisp1/algorithms/meson.build | 1 +
src/ipa/rkisp1/ipa_context.h | 4 +
4 files changed, 214 insertions(+)
create mode 100644 src/ipa/rkisp1/algorithms/goc.cpp
create mode 100644 src/ipa/rkisp1/algorithms/goc.h
diff --git a/src/ipa/rkisp1/algorithms/goc.cpp b/src/ipa/rkisp1/algorithms/goc.cpp
new file mode 100644
index 00000000..875c82e5
--- /dev/null
+++ b/src/ipa/rkisp1/algorithms/goc.cpp
@@ -0,0 +1,161 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2024, Ideas On Board
+ *
+ * RkISP1 Gamma out control
+ */
+#include "goc.h"
+
+#include <cmath>
+
+#include <libcamera/base/log.h>
+#include <libcamera/base/utils.h>
+
+#include <libcamera/control_ids.h>
+
+#include "libcamera/internal/yaml_parser.h"
+
+#include "linux/rkisp1-config.h"
+
+/**
+ * \file goc.h
+ */
+
+namespace libcamera {
+
+namespace ipa::rkisp1::algorithms {
+
+/**
+ * \class GammaOutCorrection
+ * \brief RkISP1 Gamma out correction
+ *
+ * This algorithm implements the gamma out curve for the RkISP1.
+ * It defaults to a gamma value of 2.2
+ * As gamma is internally represented as a piecewise linear function with only
+ * 17 knots, the difference between gamma=2.2 and sRGB gamma is minimal.
+ * Therefore sRGB gamma was not implemented as special case.
+ *
+ * Useful links:
+ * https://www.cambridgeincolour.com/tutorials/gamma-correction.htm
+ * https://en.wikipedia.org/wiki/SRGB
+ */
+
+LOG_DEFINE_CATEGORY(RkISP1Gamma)
+
+const double kDefaultGamma = 2.2;
+
+GammaOutCorrection::GammaOutCorrection()
+ : gamma_(0)
+{
+}
+
+/**
+ * \copydoc libcamera::ipa::Algorithm::init
+ */
+int GammaOutCorrection::init([[maybe_unused]] IPAContext &context,
+ [[maybe_unused]] const YamlObject &tuningData)
+{
+ context.ctrlMap[&controls::Gamma] = ControlInfo(0.1f, 10.0f, 2.2f);
+ defaultGamma_ = tuningData["gamma"].get<double>(kDefaultGamma);
+
+ if (context.hw->numGammaOutSamples !=
+ RKISP1_CIF_ISP_GAMMA_OUT_MAX_SAMPLES_V10) {
+ LOG(RkISP1Gamma, Error)
+ << "Gamma is not implemented for RkISP1 V12";
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+/**
+ * \brief Configure the Gamma given a configInfo
+ * \param[in] context The shared IPA context
+ * \param[in] configInfo The IPA configuration data
+ *
+ * \return 0
+ */
+int GammaOutCorrection::configure(IPAContext &context,
+ [[maybe_unused]] const IPACameraSensorInfo &configInfo)
+{
+ context.activeState.gamma = defaultGamma_;
+ return 0;
+}
+
+/**
+ * \copydoc libcamera::ipa::Algorithm::queueRequest
+ */
+void GammaOutCorrection::queueRequest([[maybe_unused]] IPAContext &context,
+ [[maybe_unused]] const uint32_t frame,
+ IPAFrameContext &frameContext,
+ const ControlList &controls)
+{
+ const auto &gamma = controls.get(controls::Gamma);
+ if (gamma) {
+ /*
+ * \todo This is not correct as it updates the current state with a
+ * future value. But it does no harm at the moment an allows us to
+ * track the last active gamma
+ */
+ context.activeState.gamma = *gamma;
+ LOG(RkISP1Gamma, Debug) << "Set gamma to " << *gamma;
+ }
+
+ frameContext.gamma = context.activeState.gamma;
+}
+
+/**
+ * \copydoc libcamera::ipa::Algorithm::prepare
+ */
+void GammaOutCorrection::prepare([[maybe_unused]] IPAContext &context,
+ const uint32_t frame,
+ [[maybe_unused]] IPAFrameContext &frameContext,
+ rkisp1_params_cfg *params)
+{
+ ASSERT(context.hw->numGammaOutSamples ==
+ RKISP1_CIF_ISP_GAMMA_OUT_MAX_SAMPLES_V10);
+
+ /*
+ * The logarithmic segments as specified in the reference.
+ * Plus an additional 0 to make the loop easier
+ */
+ std::array<unsigned, RKISP1_CIF_ISP_GAMMA_OUT_MAX_SAMPLES_V10> segments = {
+ 64, 64, 64, 64, 128, 128, 128, 128, 256,
+ 256, 256, 512, 512, 512, 512, 512, 0
+ };
+ auto gamma_y = params->others.goc_config.gamma_y;
+
+ if (frame > 0 && std::fabs(frameContext.gamma - gamma_) < 0.001)
+ return;
+
+ gamma_ = frameContext.gamma;
+
+ unsigned x = 0;
+ for (auto [i, size] : utils::enumerate(segments)) {
+ gamma_y[i] = std::pow(x / 4096.0, 1.0 / gamma_) * 1023.0;
+ x += size;
+ }
+
+ params->others.goc_config.mode = RKISP1_CIF_ISP_GOC_MODE_LOGARITHMIC;
+ params->module_cfg_update |= RKISP1_CIF_ISP_MODULE_GOC;
+ params->module_en_update |= RKISP1_CIF_ISP_MODULE_GOC;
+ params->module_ens |= RKISP1_CIF_ISP_MODULE_GOC;
+}
+
+/**
+ * \copydoc libcamera::ipa::Algorithm::process
+ */
+void GammaOutCorrection::process([[maybe_unused]] IPAContext &context,
+ [[maybe_unused]] const uint32_t frame,
+ IPAFrameContext &frameContext,
+ [[maybe_unused]] const rkisp1_stat_buffer *stats,
+ ControlList &metadata)
+{
+ metadata.set(controls::Gamma, frameContext.gamma);
+}
+
+REGISTER_IPA_ALGORITHM(GammaOutCorrection, "GammaOutCorrection")
+
+} /* namespace ipa::rkisp1::algorithms */
+
+} /* namespace libcamera */
diff --git a/src/ipa/rkisp1/algorithms/goc.h b/src/ipa/rkisp1/algorithms/goc.h
new file mode 100644
index 00000000..d45e4194
--- /dev/null
+++ b/src/ipa/rkisp1/algorithms/goc.h
@@ -0,0 +1,48 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2024, Ideas On Board
+ *
+ * RkISP1 Gamma out control
+ */
+
+#pragma once
+
+#include "algorithm.h"
+
+namespace libcamera {
+
+namespace ipa::rkisp1::algorithms {
+
+class GammaOutCorrection : public Algorithm
+{
+public:
+ GammaOutCorrection();
+ ~GammaOutCorrection() = default;
+
+ int init(IPAContext &context, const YamlObject &tuningData) override;
+ int configure(IPAContext &context, const IPACameraSensorInfo &configInfo) override;
+ void queueRequest(IPAContext &context,
+ const uint32_t frame,
+ IPAFrameContext &frameContext,
+ const ControlList &controls) override;
+ void prepare(IPAContext &context, const uint32_t frame,
+ IPAFrameContext &frameContext,
+ rkisp1_params_cfg *params) override;
+ void process(IPAContext &context, const uint32_t frame,
+ IPAFrameContext &frameContext,
+ const rkisp1_stat_buffer *stats,
+ ControlList &metadata) override;
+
+private:
+ /*
+ * \todo: gamma_ holds the current state of the hardware. context.activeState
+ * can not be used as that holds the "future state" after applying all known
+ * requests. The intended usage of activeState needs to be clarified.
+ */
+ double gamma_;
+
+ double defaultGamma_;
+};
+
+} /* namespace ipa::rkisp1::algorithms */
+} /* namespace libcamera */
diff --git a/src/ipa/rkisp1/algorithms/meson.build b/src/ipa/rkisp1/algorithms/meson.build
index 93a48329..6ee71a9b 100644
--- a/src/ipa/rkisp1/algorithms/meson.build
+++ b/src/ipa/rkisp1/algorithms/meson.build
@@ -8,6 +8,7 @@ rkisp1_ipa_algorithms = files([
'dpcc.cpp',
'dpf.cpp',
'filter.cpp',
+ 'goc.cpp',
'gsl.cpp',
'lsc.cpp',
])
diff --git a/src/ipa/rkisp1/ipa_context.h b/src/ipa/rkisp1/ipa_context.h
index bd02a7a2..5252e222 100644
--- a/src/ipa/rkisp1/ipa_context.h
+++ b/src/ipa/rkisp1/ipa_context.h
@@ -104,6 +104,8 @@ struct IPAActiveState {
uint8_t denoise;
uint8_t sharpness;
} filter;
+
+ double gamma;
};
struct IPAFrameContext : public FrameContext {
@@ -146,6 +148,8 @@ struct IPAFrameContext : public FrameContext {
uint32_t exposure;
double gain;
} sensor;
+
+ double gamma;
};
struct IPAContext {
--
2.43.0
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