diff options
| -rw-r--r-- | src/ipa/libipa/awb_grey.cpp | 114 | ||||
| -rw-r--r-- | src/ipa/libipa/awb_grey.h | 35 | ||||
| -rw-r--r-- | src/ipa/libipa/meson.build | 2 |
3 files changed, 151 insertions, 0 deletions
diff --git a/src/ipa/libipa/awb_grey.cpp b/src/ipa/libipa/awb_grey.cpp new file mode 100644 index 00000000..49448976 --- /dev/null +++ b/src/ipa/libipa/awb_grey.cpp @@ -0,0 +1,114 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ +/* + * Copyright (C) 2024 Ideas on Board Oy + * + * Base class for grey world AWB algorithm + */ + +#include "awb_grey.h" + +#include <cmath> + +#include <libcamera/base/log.h> +#include <libcamera/control_ids.h> + +#include "colours.h" + +using namespace libcamera::controls; + +/** + * \file awb_grey.h + * \brief Implementation of a grey world AWB algorithm + */ + +namespace libcamera { + +LOG_DECLARE_CATEGORY(Awb) +namespace ipa { + +/** + * \class AwbGrey + * \brief A Grey world auto white balance algorithm + */ + +/** + * \brief Initialize the algorithm with the given tuning data + * \param[in] tuningData The tuning data for the algorithm + * + * Load the colour temperature curve from the tuning data. If there is no tuning + * data available, continue with a warning. Manual colour temperature will not + * work in that case. + * + * \return 0 on success, a negative error code otherwise + */ +int AwbGrey::init(const YamlObject &tuningData) +{ + Interpolator<Vector<double, 2>> gains; + int ret = gains.readYaml(tuningData["colourGains"], "ct", "gains"); + if (ret < 0) + LOG(Awb, Warning) + << "Failed to parse 'colourGains' " + << "parameter from tuning file; " + << "manual colour temperature will not work properly"; + else + colourGainCurve_ = gains; + + return 0; +} + +/** + * \brief Calculate awb data from the given statistics + * \param[in] stats The statistics to use for the calculation + * \param[in] lux The lux value of the scene + * + * Estimates the colour temperature based on the colours::estimateCCT function. + * The gains are calculated purely based on the RGB means provided by the \a + * stats. The colour temperature is not taken into account when calculating the + * gains. + * + * The \a lux parameter is not used in this algorithm. + * + * \return The awb result + */ +AwbResult AwbGrey::calculateAwb(const AwbStats &stats, [[maybe_unused]] int lux) +{ + AwbResult result; + auto means = stats.getRGBMeans(); + result.colourTemperature = estimateCCT(means); + + /* + * Estimate the red and blue gains to apply in a grey world. The green + * gain is hardcoded to 1.0. Avoid divisions by zero by clamping the + * divisor to a minimum value of 1.0. + */ + result.gains.r() = means.g() / std::max(means.r(), 1.0); + result.gains.g() = 1.0; + result.gains.b() = means.g() / std::max(means.b(), 1.0); + return result; +} + +/** + * \brief Compute white balance gains from a colour temperature + * \param[in] colourTemperature The colour temperature in Kelvin + * + * Compute the white balance gains from a \a colourTemperature. This function + * does not take any statistics into account. It simply interpolates the colour + * gains configured in the colour temperature curve. + * + * \return The colour gains if a colour temperature curve is available, + * [1, 1, 1] otherwise. + */ +RGB<double> AwbGrey::gainsFromColourTemperature(double colourTemperature) +{ + if (!colourGainCurve_) { + LOG(Awb, Error) << "No gains defined"; + return RGB<double>({ 1.0, 1.0, 1.0 }); + } + + auto gains = colourGainCurve_->getInterpolated(colourTemperature); + return { { gains[0], 1.0, gains[1] } }; +} + +} /* namespace ipa */ + +} /* namespace libcamera */ diff --git a/src/ipa/libipa/awb_grey.h b/src/ipa/libipa/awb_grey.h new file mode 100644 index 00000000..1a365e61 --- /dev/null +++ b/src/ipa/libipa/awb_grey.h @@ -0,0 +1,35 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ +/* + * Copyright (C) 2024 Ideas on Board Oy + * + * AWB grey world algorithm + */ + +#pragma once + +#include "libcamera/internal/vector.h" +#include "libcamera/internal/yaml_parser.h" + +#include "awb.h" +#include "interpolator.h" + +namespace libcamera { + +namespace ipa { + +class AwbGrey : public AwbAlgorithm +{ +public: + AwbGrey() = default; + + int init(const YamlObject &tuningData) override; + AwbResult calculateAwb(const AwbStats &stats, int lux) override; + RGB<double> gainsFromColourTemperature(double colourTemperature) override; + +private: + std::optional<Interpolator<Vector<double, 2>>> colourGainCurve_; +}; + +} /* namespace ipa */ + +} /* namespace libcamera */ diff --git a/src/ipa/libipa/meson.build b/src/ipa/libipa/meson.build index 5be51d2c..3c23f168 100644 --- a/src/ipa/libipa/meson.build +++ b/src/ipa/libipa/meson.build @@ -3,6 +3,7 @@ libipa_headers = files([ 'agc_mean_luminance.h', 'algorithm.h', + 'awb_grey.h', 'awb.h', 'camera_sensor_helper.h', 'colours.h', @@ -20,6 +21,7 @@ libipa_headers = files([ libipa_sources = files([ 'agc_mean_luminance.cpp', 'algorithm.cpp', + 'awb_grey.cpp', 'awb.cpp', 'camera_sensor_helper.cpp', 'colours.cpp', |