/* SPDX-License-Identifier: BSD-2-Clause */ /* * Copyright (C) 2019, Raspberry Pi (Trading) Limited * * lux.cpp - Lux control algorithm */ #include <math.h> #include "linux/bcm2835-isp.h" #include "../device_status.h" #include "../logging.hpp" #include "lux.hpp" using namespace RPi; #define NAME "rpi.lux" Lux::Lux(Controller *controller) : Algorithm(controller) { // Put in some defaults as there will be no meaningful values until // Process has run. status_.aperture = 1.0; status_.lux = 400; } char const *Lux::Name() const { return NAME; } void Lux::Read(boost::property_tree::ptree const ¶ms) { RPI_LOG(Name()); reference_shutter_speed_ = params.get<double>("reference_shutter_speed"); reference_gain_ = params.get<double>("reference_gain"); reference_aperture_ = params.get<double>("reference_aperture", 1.0); reference_Y_ = params.get<double>("reference_Y"); reference_lux_ = params.get<double>("reference_lux"); current_aperture_ = reference_aperture_; } void Lux::Prepare(Metadata *image_metadata) { std::unique_lock<std::mutex> lock(mutex_); image_metadata->Set("lux.status", status_); } void Lux::Process(StatisticsPtr &stats, Metadata *image_metadata) { // set some initial values to shut the compiler up DeviceStatus device_status = { .shutter_speed = 1.0, .analogue_gain = 1.0, .lens_position = 0.0, .aperture = 0.0, .flash_intensity = 0.0 }; if (image_metadata->Get("device.status", device_status) == 0) { double current_gain = device_status.analogue_gain; double current_shutter_speed = device_status.shutter_speed; double current_aperture = device_status.aperture; if (current_aperture == 0) current_aperture = current_aperture_; uint64_t sum = 0; uint32_t num = 0; uint32_t *bin = stats->hist[0].g_hist; const int num_bins = sizeof(stats->hist[0].g_hist) / sizeof(stats->hist[0].g_hist[0]); for (int i = 0; i < num_bins; i++) sum += bin[i] * (uint64_t)i, num += bin[i]; // add .5 to reflect the mid-points of bins double current_Y = sum / (double)num + .5; double gain_ratio = reference_gain_ / current_gain; double shutter_speed_ratio = reference_shutter_speed_ / current_shutter_speed; double aperture_ratio = reference_aperture_ / current_aperture; double Y_ratio = current_Y * (65536 / num_bins) / reference_Y_; double estimated_lux = shutter_speed_ratio * gain_ratio * aperture_ratio * aperture_ratio * Y_ratio * reference_lux_; LuxStatus status; status.lux = estimated_lux; status.aperture = current_aperture; RPI_LOG(Name() << ": estimated lux " << estimated_lux); { std::unique_lock<std::mutex> lock(mutex_); status_ = status; } // Overwrite the metadata here as well, so that downstream // algorithms get the latest value. image_metadata->Set("lux.status", status); } else RPI_WARN(Name() << ": no device metadata"); } // Register algorithm with the system. static Algorithm *Create(Controller *controller) { return (Algorithm *)new Lux(controller); } static RegisterAlgorithm reg(NAME, &Create);