diff options
Diffstat (limited to 'src/ipa/rpi/controller/rpi/alsc.h')
| -rw-r--r-- | src/ipa/rpi/controller/rpi/alsc.h | 174 |
1 files changed, 174 insertions, 0 deletions
diff --git a/src/ipa/rpi/controller/rpi/alsc.h b/src/ipa/rpi/controller/rpi/alsc.h new file mode 100644 index 00000000..0b6d9478 --- /dev/null +++ b/src/ipa/rpi/controller/rpi/alsc.h @@ -0,0 +1,174 @@ +/* SPDX-License-Identifier: BSD-2-Clause */ +/* + * Copyright (C) 2019, Raspberry Pi Ltd + * + * alsc.h - ALSC (auto lens shading correction) control algorithm + */ +#pragma once + +#include <array> +#include <mutex> +#include <condition_variable> +#include <thread> +#include <vector> + +#include <libcamera/geometry.h> + +#include "../algorithm.h" +#include "../alsc_status.h" +#include "../statistics.h" + +namespace RPiController { + +/* Algorithm to generate automagic LSC (Lens Shading Correction) tables. */ + +/* + * The Array2D class is a very thin wrapper round std::vector so that it can + * be used in exactly the same way in the code but carries its correct width + * and height ("dimensions") with it. + */ + +template<typename T> +class Array2D +{ +public: + using Size = libcamera::Size; + + const Size &dimensions() const { return dimensions_; } + + size_t size() const { return data_.size(); } + + const std::vector<T> &data() const { return data_; } + + void resize(const Size &dims) + { + dimensions_ = dims; + data_.resize(dims.width * dims.height); + } + + void resize(const Size &dims, const T &value) + { + resize(dims); + std::fill(data_.begin(), data_.end(), value); + } + + T &operator[](int index) { return data_[index]; } + + const T &operator[](int index) const { return data_[index]; } + + T *ptr() { return data_.data(); } + + const T *ptr() const { return data_.data(); } + + auto begin() { return data_.begin(); } + auto end() { return data_.end(); } + +private: + Size dimensions_; + std::vector<T> data_; +}; + +/* + * We'll use the term SparseArray for the large sparse matrices that are + * XY tall but have only 4 non-zero elements on each row. + */ + +template<typename T> +using SparseArray = std::vector<std::array<T, 4>>; + +struct AlscCalibration { + double ct; + Array2D<double> table; +}; + +struct AlscConfig { + /* Only repeat the ALSC calculation every "this many" frames */ + uint16_t framePeriod; + /* number of initial frames for which speed taken as 1.0 (maximum) */ + uint16_t startupFrames; + /* IIR filter speed applied to algorithm results */ + double speed; + double sigmaCr; + double sigmaCb; + double minCount; + uint16_t minG; + double omega; + uint32_t nIter; + Array2D<double> luminanceLut; + double luminanceStrength; + std::vector<AlscCalibration> calibrationsCr; + std::vector<AlscCalibration> calibrationsCb; + double defaultCt; /* colour temperature if no metadata found */ + double threshold; /* iteration termination threshold */ + double lambdaBound; /* upper/lower bound for lambda from a value of 1 */ + libcamera::Size tableSize; +}; + +class Alsc : public Algorithm +{ +public: + Alsc(Controller *controller = NULL); + ~Alsc(); + char const *name() const override; + void initialise() override; + void switchMode(CameraMode const &cameraMode, Metadata *metadata) override; + int read(const libcamera::YamlObject ¶ms) override; + void prepare(Metadata *imageMetadata) override; + void process(StatisticsPtr &stats, Metadata *imageMetadata) override; + +private: + /* configuration is read-only, and available to both threads */ + AlscConfig config_; + bool firstTime_; + CameraMode cameraMode_; + Array2D<double> luminanceTable_; + std::thread asyncThread_; + void asyncFunc(); /* asynchronous thread function */ + std::mutex mutex_; + /* condvar for async thread to wait on */ + std::condition_variable asyncSignal_; + /* condvar for synchronous thread to wait on */ + std::condition_variable syncSignal_; + /* for sync thread to check if async thread finished (requires mutex) */ + bool asyncFinished_; + /* for async thread to check if it's been told to run (requires mutex) */ + bool asyncStart_; + /* for async thread to check if it's been told to quit (requires mutex) */ + bool asyncAbort_; + + /* + * The following are only for the synchronous thread to use: + * for sync thread to note its has asked async thread to run + */ + bool asyncStarted_; + /* counts up to framePeriod before restarting the async thread */ + int framePhase_; + /* counts up to startupFrames */ + int frameCount_; + /* counts up to startupFrames for Process function */ + int frameCount2_; + std::array<Array2D<double>, 3> syncResults_; + std::array<Array2D<double>, 3> prevSyncResults_; + void waitForAysncThread(); + /* + * The following are for the asynchronous thread to use, though the main + * thread can set/reset them if the async thread is known to be idle: + */ + void restartAsync(StatisticsPtr &stats, Metadata *imageMetadata); + /* copy out the results from the async thread so that it can be restarted */ + void fetchAsyncResults(); + double ct_; + RgbyRegions statistics_; + std::array<Array2D<double>, 3> asyncResults_; + Array2D<double> asyncLambdaR_; + Array2D<double> asyncLambdaB_; + void doAlsc(); + Array2D<double> lambdaR_; + Array2D<double> lambdaB_; + + /* Temporaries for the computations */ + std::array<Array2D<double>, 5> tmpC_; + std::array<SparseArray<double>, 3> tmpM_; +}; + +} /* namespace RPiController */ |