/* SPDX-License-Identifier: BSD-2-Clause */ /* * Copyright (C) 2019, Raspberry Pi (Trading) Limited * * noise.cpp - Noise control algorithm */ #include <math.h> #include <libcamera/base/log.h> #include "../device_status.h" #include "../noise_status.h" #include "noise.hpp" using namespace RPiController; using namespace libcamera; LOG_DEFINE_CATEGORY(RPiNoise) #define NAME "rpi.noise" Noise::Noise(Controller *controller) : Algorithm(controller), mode_factor_(1.0) { } char const *Noise::Name() const { return NAME; } void Noise::SwitchMode(CameraMode const &camera_mode, [[maybe_unused]] Metadata *metadata) { // For example, we would expect a 2x2 binned mode to have a "noise // factor" of sqrt(2x2) = 2. (can't be less than one, right?) mode_factor_ = std::max(1.0, camera_mode.noise_factor); } void Noise::Read(boost::property_tree::ptree const ¶ms) { reference_constant_ = params.get<double>("reference_constant"); reference_slope_ = params.get<double>("reference_slope"); } void Noise::Prepare(Metadata *image_metadata) { struct DeviceStatus device_status; device_status.analogue_gain = 1.0; // keep compiler calm if (image_metadata->Get("device.status", device_status) == 0) { // There is a slight question as to exactly how the noise // profile, specifically the constant part of it, scales. For // now we assume it all scales the same, and we'll revisit this // if it proves substantially wrong. NOTE: we may also want to // make some adjustments based on the camera mode (such as // binning), if we knew how to discover it... double factor = sqrt(device_status.analogue_gain) / mode_factor_; struct NoiseStatus status; status.noise_constant = reference_constant_ * factor; status.noise_slope = reference_slope_ * factor; image_metadata->Set("noise.status", status); LOG(RPiNoise, Debug) << "constant " << status.noise_constant << " slope " << status.noise_slope; } else LOG(RPiNoise, Warning) << " no metadata"; } // Register algorithm with the system. static Algorithm *Create(Controller *controller) { return new Noise(controller); } static RegisterAlgorithm reg(NAME, &Create);