[PATCH v3 3/3] ipa: rkisp1: Add GammaOutCorrection algorithm
Kieran Bingham
kieran.bingham at ideasonboard.com
Mon Jun 3 17:57:25 CEST 2024
Quoting Stefan Klug (2024-06-03 15:06:30)
> 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";
Is that because the size is different? Are there other differences that
prevent us supporting it ?
> + 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
Is the '0' still required now that this uses utils::enumerate(segments)?
> + */
> + 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
> + };
Presumably we'd have different segments for V12 ?
> + 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;
Assuming the '0' is actually valid, as I think the last iteration
through this loop will still have added x by 512 anyway,
Reviewed-by: Kieran Bingham <kieran.bingham at ideasonboard.com>
> + }
> +
> + 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
>
More information about the libcamera-devel
mailing list