/* SPDX-License-Identifier: BSD-2-Clause */ /* * Copyright (C) 2019, Raspberry Pi Ltd * * awb.h - AWB control algorithm */ #pragma once #include <mutex> #include <condition_variable> #include <thread> #include "../awb_algorithm.h" #include "../pwl.h" #include "../awb_status.h" #include "../statistics.h" namespace RPiController { /* Control algorithm to perform AWB calculations. */ struct AwbMode { int read(const libcamera::YamlObject ¶ms); double ctLo; /* low CT value for search */ double ctHi; /* high CT value for search */ }; struct AwbPrior { int read(const libcamera::YamlObject ¶ms); double lux; /* lux level */ Pwl prior; /* maps CT to prior log likelihood for this lux level */ }; struct AwbConfig { AwbConfig() : defaultMode(nullptr) {} int read(const libcamera::YamlObject ¶ms); /* Only repeat the AWB calculation every "this many" frames */ uint16_t framePeriod; /* number of initial frames for which speed taken as 1.0 (maximum) */ uint16_t startupFrames; unsigned int convergenceFrames; /* approx number of frames to converge */ double speed; /* IIR filter speed applied to algorithm results */ bool fast; /* "fast" mode uses a 16x16 rather than 32x32 grid */ Pwl ctR; /* function maps CT to r (= R/G) */ Pwl ctB; /* function maps CT to b (= B/G) */ Pwl ctRInverse; /* inverse of ctR */ Pwl ctBInverse; /* inverse of ctB */ /* table of illuminant priors at different lux levels */ std::vector<AwbPrior> priors; /* AWB "modes" (determines the search range) */ std::map<std::string, AwbMode> modes; AwbMode *defaultMode; /* mode used if no mode selected */ /* * minimum proportion of pixels counted within AWB region for it to be * "useful" */ double minPixels; /* minimum G value of those pixels, to be regarded a "useful" */ uint16_t minG; /* * number of AWB regions that must be "useful" in order to do the AWB * calculation */ uint32_t minRegions; /* clamp on colour error term (so as not to penalise non-grey excessively) */ double deltaLimit; /* step size control in coarse search */ double coarseStep; /* how far to wander off CT curve towards "more purple" */ double transversePos; /* how far to wander off CT curve towards "more green" */ double transverseNeg; /* * red sensitivity ratio (set to canonical sensor's R/G divided by this * sensor's R/G) */ double sensitivityR; /* * blue sensitivity ratio (set to canonical sensor's B/G divided by this * sensor's B/G) */ double sensitivityB; /* The whitepoint (which we normally "aim" for) can be moved. */ double whitepointR; double whitepointB; bool bayes; /* use Bayesian algorithm */ }; class Awb : public AwbAlgorithm { public: Awb(Controller *controller = NULL); ~Awb(); char const *name() const override; void initialise() override; int read(const libcamera::YamlObject ¶ms) override; unsigned int getConvergenceFrames() const override; void setMode(std::string const &name) override; void setManualGains(double manualR, double manualB) override; void enableAuto() override; void disableAuto() override; void switchMode(CameraMode const &cameraMode, Metadata *metadata) override; void prepare(Metadata *imageMetadata) override; void process(StatisticsPtr &stats, Metadata *imageMetadata) override; struct RGB { RGB(double r = 0, double g = 0, double b = 0) : R(r), G(g), B(b) { } double R, G, B; RGB &operator+=(RGB const &other) { R += other.R, G += other.G, B += other.B; return *this; } }; private: bool isAutoEnabled() const; /* configuration is read-only, and available to both threads */ AwbConfig config_; 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_; int frameCount_; /* counts up to startup_frames */ AwbStatus syncResults_; AwbStatus prevSyncResults_; std::string modeName_; /* * 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, double lux); /* copy out the results from the async thread so that it can be restarted */ void fetchAsyncResults(); StatisticsPtr statistics_; AwbMode *mode_; double lux_; AwbStatus asyncResults_; void doAwb(); void awbBayes(); void awbGrey(); void prepareStats(); double computeDelta2Sum(double gainR, double gainB); Pwl interpolatePrior(); double coarseSearch(Pwl const &prior); void fineSearch(double &t, double &r, double &b, Pwl const &prior); std::vector<RGB> zones_; std::vector<Pwl::Point> points_; /* manual r setting */ double manualR_; /* manual b setting */ double manualB_; }; static inline Awb::RGB operator+(Awb::RGB const &a, Awb::RGB const &b) { return Awb::RGB(a.R + b.R, a.G + b.G, a.B + b.B); } static inline Awb::RGB operator-(Awb::RGB const &a, Awb::RGB const &b) { return Awb::RGB(a.R - b.R, a.G - b.G, a.B - b.B); } static inline Awb::RGB operator*(double d, Awb::RGB const &rgb) { return Awb::RGB(d * rgb.R, d * rgb.G, d * rgb.B); } static inline Awb::RGB operator*(Awb::RGB const &rgb, double d) { return d * rgb; } } /* namespace RPiController */