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Diffstat (limited to 'src/ipa/raspberrypi/controller/rpi/alsc.cpp')
| -rw-r--r-- | src/ipa/raspberrypi/controller/rpi/alsc.cpp | 705 |
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diff --git a/src/ipa/raspberrypi/controller/rpi/alsc.cpp b/src/ipa/raspberrypi/controller/rpi/alsc.cpp new file mode 100644 index 00000000..821a0ca3 --- /dev/null +++ b/src/ipa/raspberrypi/controller/rpi/alsc.cpp @@ -0,0 +1,705 @@ +/* SPDX-License-Identifier: BSD-2-Clause */ +/* + * Copyright (C) 2019, Raspberry Pi (Trading) Limited + * + * alsc.cpp - ALSC (auto lens shading correction) control algorithm + */ +#include <math.h> + +#include "../awb_status.h" +#include "alsc.hpp" + +// Raspberry Pi ALSC (Auto Lens Shading Correction) algorithm. + +using namespace RPi; + +#define NAME "rpi.alsc" + +static const int X = ALSC_CELLS_X; +static const int Y = ALSC_CELLS_Y; +static const int XY = X * Y; +static const double INSUFFICIENT_DATA = -1.0; + +Alsc::Alsc(Controller *controller) + : Algorithm(controller) +{ + async_abort_ = async_start_ = async_started_ = async_finished_ = false; + async_thread_ = std::thread(std::bind(&Alsc::asyncFunc, this)); +} + +Alsc::~Alsc() +{ + { + std::lock_guard<std::mutex> lock(mutex_); + async_abort_ = true; + async_signal_.notify_one(); + } + async_thread_.join(); +} + +char const *Alsc::Name() const +{ + return NAME; +} + +static void generate_lut(double *lut, boost::property_tree::ptree const ¶ms) +{ + double cstrength = params.get<double>("corner_strength", 2.0); + if (cstrength <= 1.0) + throw std::runtime_error("Alsc: corner_strength must be > 1.0"); + double asymmetry = params.get<double>("asymmetry", 1.0); + if (asymmetry < 0) + throw std::runtime_error("Alsc: asymmetry must be >= 0"); + double f1 = cstrength - 1, f2 = 1 + sqrt(cstrength); + double R2 = X * Y / 4 * (1 + asymmetry * asymmetry); + int num = 0; + for (int y = 0; y < Y; y++) { + for (int x = 0; x < X; x++) { + double dy = y - Y / 2 + 0.5, + dx = (x - X / 2 + 0.5) * asymmetry; + double r2 = (dx * dx + dy * dy) / R2; + lut[num++] = + (f1 * r2 + f2) * (f1 * r2 + f2) / + (f2 * f2); // this reproduces the cos^4 rule + } + } +} + +static void read_lut(double *lut, boost::property_tree::ptree const ¶ms) +{ + int num = 0; + const int max_num = XY; + for (auto &p : params) { + if (num == max_num) + throw std::runtime_error( + "Alsc: too many entries in LSC table"); + lut[num++] = p.second.get_value<double>(); + } + if (num < max_num) + throw std::runtime_error("Alsc: too few entries in LSC table"); +} + +static void read_calibrations(std::vector<AlscCalibration> &calibrations, + boost::property_tree::ptree const ¶ms, + std::string const &name) +{ + if (params.get_child_optional(name)) { + double last_ct = 0; + for (auto &p : params.get_child(name)) { + double ct = p.second.get<double>("ct"); + if (ct <= last_ct) + throw std::runtime_error( + "Alsc: entries in " + name + + " must be in increasing ct order"); + AlscCalibration calibration; + calibration.ct = last_ct = ct; + boost::property_tree::ptree const &table = + p.second.get_child("table"); + int num = 0; + for (auto it = table.begin(); it != table.end(); it++) { + if (num == XY) + throw std::runtime_error( + "Alsc: too many values for ct " + + std::to_string(ct) + " in " + + name); + calibration.table[num++] = + it->second.get_value<double>(); + } + if (num != XY) + throw std::runtime_error( + "Alsc: too few values for ct " + + std::to_string(ct) + " in " + name); + calibrations.push_back(calibration); + RPI_LOG("Read " << name << " calibration for ct " + << ct); + } + } +} + +void Alsc::Read(boost::property_tree::ptree const ¶ms) +{ + RPI_LOG("Alsc"); + config_.frame_period = params.get<uint16_t>("frame_period", 12); + config_.startup_frames = params.get<uint16_t>("startup_frames", 10); + config_.speed = params.get<double>("speed", 0.05); + double sigma = params.get<double>("sigma", 0.01); + config_.sigma_Cr = params.get<double>("sigma_Cr", sigma); + config_.sigma_Cb = params.get<double>("sigma_Cb", sigma); + config_.min_count = params.get<double>("min_count", 10.0); + config_.min_G = params.get<uint16_t>("min_G", 50); + config_.omega = params.get<double>("omega", 1.3); + config_.n_iter = params.get<uint32_t>("n_iter", X + Y); + config_.luminance_strength = + params.get<double>("luminance_strength", 1.0); + for (int i = 0; i < XY; i++) + config_.luminance_lut[i] = 1.0; + if (params.get_child_optional("corner_strength")) + generate_lut(config_.luminance_lut, params); + else if (params.get_child_optional("luminance_lut")) + read_lut(config_.luminance_lut, + params.get_child("luminance_lut")); + else + RPI_WARN("Alsc: no luminance table - assume unity everywhere"); + read_calibrations(config_.calibrations_Cr, params, "calibrations_Cr"); + read_calibrations(config_.calibrations_Cb, params, "calibrations_Cb"); + config_.default_ct = params.get<double>("default_ct", 4500.0); + config_.threshold = params.get<double>("threshold", 1e-3); +} + +static void get_cal_table(double ct, + std::vector<AlscCalibration> const &calibrations, + double cal_table[XY]); +static void resample_cal_table(double const cal_table_in[XY], + CameraMode const &camera_mode, + double cal_table_out[XY]); +static void compensate_lambdas_for_cal(double const cal_table[XY], + double const old_lambdas[XY], + double new_lambdas[XY]); +static void add_luminance_to_tables(double results[3][Y][X], + double const lambda_r[XY], double lambda_g, + double const lambda_b[XY], + double const luminance_lut[XY], + double luminance_strength); + +void Alsc::Initialise() +{ + RPI_LOG("Alsc"); + frame_count2_ = frame_count_ = frame_phase_ = 0; + first_time_ = true; + // Initialise the lambdas. Each call to Process then restarts from the + // previous results. Also initialise the previous frame tables to the + // same harmless values. + for (int i = 0; i < XY; i++) + lambda_r_[i] = lambda_b_[i] = 1.0; +} + +void Alsc::SwitchMode(CameraMode const &camera_mode) +{ + // There's a bit of a question what we should do if the "crop" of the + // camera mode has changed. Any calculation currently in flight would + // not be useful to the new mode, so arguably we should abort it, and + // generate a new table (like the "first_time" code already here). When + // the crop doesn't change, we can presumably just leave things + // alone. For now, I think we'll just wait and see. When the crop does + // change, any effects should be transient, and if they're not transient + // enough, we'll revisit the question then. + camera_mode_ = camera_mode; + if (first_time_) { + // On the first time, arrange for something sensible in the + // initial tables. Construct the tables for some default colour + // temperature. This echoes the code in doAlsc, without the + // adaptive algorithm. + double cal_table_r[XY], cal_table_b[XY], cal_table_tmp[XY]; + get_cal_table(4000, config_.calibrations_Cr, cal_table_tmp); + resample_cal_table(cal_table_tmp, camera_mode_, cal_table_r); + get_cal_table(4000, config_.calibrations_Cb, cal_table_tmp); + resample_cal_table(cal_table_tmp, camera_mode_, cal_table_b); + compensate_lambdas_for_cal(cal_table_r, lambda_r_, + async_lambda_r_); + compensate_lambdas_for_cal(cal_table_b, lambda_b_, + async_lambda_b_); + add_luminance_to_tables(sync_results_, async_lambda_r_, 1.0, + async_lambda_b_, config_.luminance_lut, + config_.luminance_strength); + memcpy(prev_sync_results_, sync_results_, + sizeof(prev_sync_results_)); + first_time_ = false; + } +} + +void Alsc::fetchAsyncResults() +{ + RPI_LOG("Fetch ALSC results"); + async_finished_ = false; + async_started_ = false; + memcpy(sync_results_, async_results_, sizeof(sync_results_)); +} + +static double get_ct(Metadata *metadata, double default_ct) +{ + AwbStatus awb_status; + awb_status.temperature_K = default_ct; // in case nothing found + if (metadata->Get("awb.status", awb_status) != 0) + RPI_WARN("Alsc: no AWB results found, using " + << awb_status.temperature_K); + else + RPI_LOG("Alsc: AWB results found, using " + << awb_status.temperature_K); + return awb_status.temperature_K; +} + +static void copy_stats(bcm2835_isp_stats_region regions[XY], StatisticsPtr &stats, + AlscStatus const &status) +{ + bcm2835_isp_stats_region *input_regions = stats->awb_stats; + double *r_table = (double *)status.r; + double *g_table = (double *)status.g; + double *b_table = (double *)status.b; + for (int i = 0; i < XY; i++) { + regions[i].r_sum = input_regions[i].r_sum / r_table[i]; + regions[i].g_sum = input_regions[i].g_sum / g_table[i]; + regions[i].b_sum = input_regions[i].b_sum / b_table[i]; + regions[i].counted = input_regions[i].counted; + // (don't care about the uncounted value) + } +} + +void Alsc::restartAsync(StatisticsPtr &stats, Metadata *image_metadata) +{ + RPI_LOG("Starting ALSC thread"); + // Get the current colour temperature. It's all we need from the + // metadata. + ct_ = get_ct(image_metadata, config_.default_ct); + // We have to copy the statistics here, dividing out our best guess of + // the LSC table that the pipeline applied to them. + AlscStatus alsc_status; + if (image_metadata->Get("alsc.status", alsc_status) != 0) { + RPI_WARN("No ALSC status found for applied gains!"); + for (int y = 0; y < Y; y++) + for (int x = 0; x < X; x++) { + alsc_status.r[y][x] = 1.0; + alsc_status.g[y][x] = 1.0; + alsc_status.b[y][x] = 1.0; + } + } + copy_stats(statistics_, stats, alsc_status); + frame_phase_ = 0; + // copy the camera mode so it won't change during the calculations + async_camera_mode_ = camera_mode_; + async_start_ = true; + async_started_ = true; + async_signal_.notify_one(); +} + +void Alsc::Prepare(Metadata *image_metadata) +{ + // Count frames since we started, and since we last poked the async + // thread. + if (frame_count_ < (int)config_.startup_frames) + frame_count_++; + double speed = frame_count_ < (int)config_.startup_frames + ? 1.0 + : config_.speed; + RPI_LOG("Alsc: frame_count " << frame_count_ << " speed " << speed); + { + std::unique_lock<std::mutex> lock(mutex_); + if (async_started_ && async_finished_) { + RPI_LOG("ALSC thread finished"); + fetchAsyncResults(); + } + } + // Apply IIR filter to results and program into the pipeline. + double *ptr = (double *)sync_results_, + *pptr = (double *)prev_sync_results_; + for (unsigned int i = 0; + i < sizeof(sync_results_) / sizeof(double); i++) + pptr[i] = speed * ptr[i] + (1.0 - speed) * pptr[i]; + // Put output values into status metadata. + AlscStatus status; + memcpy(status.r, prev_sync_results_[0], sizeof(status.r)); + memcpy(status.g, prev_sync_results_[1], sizeof(status.g)); + memcpy(status.b, prev_sync_results_[2], sizeof(status.b)); + image_metadata->Set("alsc.status", status); +} + +void Alsc::Process(StatisticsPtr &stats, Metadata *image_metadata) +{ + // Count frames since we started, and since we last poked the async + // thread. + if (frame_phase_ < (int)config_.frame_period) + frame_phase_++; + if (frame_count2_ < (int)config_.startup_frames) + frame_count2_++; + RPI_LOG("Alsc: frame_phase " << frame_phase_); + if (frame_phase_ >= (int)config_.frame_period || + frame_count2_ < (int)config_.startup_frames) { + std::unique_lock<std::mutex> lock(mutex_); + if (async_started_ == false) { + RPI_LOG("ALSC thread starting"); + restartAsync(stats, image_metadata); + } + } +} + +void Alsc::asyncFunc() +{ + while (true) { + { + std::unique_lock<std::mutex> lock(mutex_); + async_signal_.wait(lock, [&] { + return async_start_ || async_abort_; + }); + async_start_ = false; + if (async_abort_) + break; + } + doAlsc(); + { + std::lock_guard<std::mutex> lock(mutex_); + async_finished_ = true; + sync_signal_.notify_one(); + } + } +} + +void get_cal_table(double ct, std::vector<AlscCalibration> const &calibrations, + double cal_table[XY]) +{ + if (calibrations.empty()) { + for (int i = 0; i < XY; i++) + cal_table[i] = 1.0; + RPI_LOG("Alsc: no calibrations found"); + } else if (ct <= calibrations.front().ct) { + memcpy(cal_table, calibrations.front().table, + XY * sizeof(double)); + RPI_LOG("Alsc: using calibration for " + << calibrations.front().ct); + } else if (ct >= calibrations.back().ct) { + memcpy(cal_table, calibrations.back().table, + XY * sizeof(double)); + RPI_LOG("Alsc: using calibration for " + << calibrations.front().ct); + } else { + int idx = 0; + while (ct > calibrations[idx + 1].ct) + idx++; + double ct0 = calibrations[idx].ct, + ct1 = calibrations[idx + 1].ct; + RPI_LOG("Alsc: ct is " << ct << ", interpolating between " + << ct0 << " and " << ct1); + for (int i = 0; i < XY; i++) + cal_table[i] = + (calibrations[idx].table[i] * (ct1 - ct) + + calibrations[idx + 1].table[i] * (ct - ct0)) / + (ct1 - ct0); + } +} + +void resample_cal_table(double const cal_table_in[XY], + CameraMode const &camera_mode, double cal_table_out[XY]) +{ + // Precalculate and cache the x sampling locations and phases to save + // recomputing them on every row. + int x_lo[X], x_hi[X]; + double xf[X]; + double scale_x = camera_mode.sensor_width / + (camera_mode.width * camera_mode.scale_x); + double x_off = camera_mode.crop_x / (double)camera_mode.sensor_width; + double x = .5 / scale_x + x_off * X - .5; + double x_inc = 1 / scale_x; + for (int i = 0; i < X; i++, x += x_inc) { + x_lo[i] = floor(x); + xf[i] = x - x_lo[i]; + x_hi[i] = std::min(x_lo[i] + 1, X - 1); + x_lo[i] = std::max(x_lo[i], 0); + } + // Now march over the output table generating the new values. + double scale_y = camera_mode.sensor_height / + (camera_mode.height * camera_mode.scale_y); + double y_off = camera_mode.crop_y / (double)camera_mode.sensor_height; + double y = .5 / scale_y + y_off * Y - .5; + double y_inc = 1 / scale_y; + for (int j = 0; j < Y; j++, y += y_inc) { + int y_lo = floor(y); + double yf = y - y_lo; + int y_hi = std::min(y_lo + 1, Y - 1); + y_lo = std::max(y_lo, 0); + double const *row_above = cal_table_in + X * y_lo; + double const *row_below = cal_table_in + X * y_hi; + for (int i = 0; i < X; i++) { + double above = row_above[x_lo[i]] * (1 - xf[i]) + + row_above[x_hi[i]] * xf[i]; + double below = row_below[x_lo[i]] * (1 - xf[i]) + + row_below[x_hi[i]] * xf[i]; + *(cal_table_out++) = above * (1 - yf) + below * yf; + } + } +} + +// Calculate chrominance statistics (R/G and B/G) for each region. +static_assert(XY == AWB_REGIONS, "ALSC/AWB statistics region mismatch"); +static void calculate_Cr_Cb(bcm2835_isp_stats_region *awb_region, double Cr[XY], + double Cb[XY], uint32_t min_count, uint16_t min_G) +{ + for (int i = 0; i < XY; i++) { + bcm2835_isp_stats_region &zone = awb_region[i]; + if (zone.counted <= min_count || + zone.g_sum / zone.counted <= min_G) { + Cr[i] = Cb[i] = INSUFFICIENT_DATA; + continue; + } + Cr[i] = zone.r_sum / (double)zone.g_sum; + Cb[i] = zone.b_sum / (double)zone.g_sum; + } +} + +static void apply_cal_table(double const cal_table[XY], double C[XY]) +{ + for (int i = 0; i < XY; i++) + if (C[i] != INSUFFICIENT_DATA) + C[i] *= cal_table[i]; +} + +void compensate_lambdas_for_cal(double const cal_table[XY], + double const old_lambdas[XY], + double new_lambdas[XY]) +{ + double min_new_lambda = std::numeric_limits<double>::max(); + for (int i = 0; i < XY; i++) { + new_lambdas[i] = old_lambdas[i] * cal_table[i]; + min_new_lambda = std::min(min_new_lambda, new_lambdas[i]); + } + for (int i = 0; i < XY; i++) + new_lambdas[i] /= min_new_lambda; +} + +static void print_cal_table(double const C[XY]) +{ + printf("table: [\n"); + for (int j = 0; j < Y; j++) { + for (int i = 0; i < X; i++) { + printf("%5.3f", 1.0 / C[j * X + i]); + if (i != X - 1 || j != Y - 1) + printf(","); + } + printf("\n"); + } + printf("]\n"); +} + +// Compute weight out of 1.0 which reflects how similar we wish to make the +// colours of these two regions. +static double compute_weight(double C_i, double C_j, double sigma) +{ + if (C_i == INSUFFICIENT_DATA || C_j == INSUFFICIENT_DATA) + return 0; + double diff = (C_i - C_j) / sigma; + return exp(-diff * diff / 2); +} + +// Compute all weights. +static void compute_W(double const C[XY], double sigma, double W[XY][4]) +{ + for (int i = 0; i < XY; i++) { + // Start with neighbour above and go clockwise. + W[i][0] = i >= X ? compute_weight(C[i], C[i - X], sigma) : 0; + W[i][1] = i % X < X - 1 ? compute_weight(C[i], C[i + 1], sigma) + : 0; + W[i][2] = + i < XY - X ? compute_weight(C[i], C[i + X], sigma) : 0; + W[i][3] = i % X ? compute_weight(C[i], C[i - 1], sigma) : 0; + } +} + +// Compute M, the large but sparse matrix such that M * lambdas = 0. +static void construct_M(double const C[XY], double const W[XY][4], + double M[XY][4]) +{ + double epsilon = 0.001; + for (int i = 0; i < XY; i++) { + // Note how, if C[i] == INSUFFICIENT_DATA, the weights will all + // be zero so the equation is still set up correctly. + int m = !!(i >= X) + !!(i % X < X - 1) + !!(i < XY - X) + + !!(i % X); // total number of neighbours + // we'll divide the diagonal out straight away + double diagonal = + (epsilon + W[i][0] + W[i][1] + W[i][2] + W[i][3]) * + C[i]; + M[i][0] = i >= X ? (W[i][0] * C[i - X] + epsilon / m * C[i]) / + diagonal + : 0; + M[i][1] = i % X < X - 1 + ? (W[i][1] * C[i + 1] + epsilon / m * C[i]) / + diagonal + : 0; + M[i][2] = i < XY - X + ? (W[i][2] * C[i + X] + epsilon / m * C[i]) / + diagonal + : 0; + M[i][3] = i % X ? (W[i][3] * C[i - 1] + epsilon / m * C[i]) / + diagonal + : 0; + } +} + +// In the compute_lambda_ functions, note that the matrix coefficients for the +// left/right neighbours are zero down the left/right edges, so we don't need +// need to test the i value to exclude them. +static double compute_lambda_bottom(int i, double const M[XY][4], + double lambda[XY]) +{ + return M[i][1] * lambda[i + 1] + M[i][2] * lambda[i + X] + + M[i][3] * lambda[i - 1]; +} +static double compute_lambda_bottom_start(int i, double const M[XY][4], + double lambda[XY]) +{ + return M[i][1] * lambda[i + 1] + M[i][2] * lambda[i + X]; +} +static double compute_lambda_interior(int i, double const M[XY][4], + double lambda[XY]) +{ + return M[i][0] * lambda[i - X] + M[i][1] * lambda[i + 1] + + M[i][2] * lambda[i + X] + M[i][3] * lambda[i - 1]; +} +static double compute_lambda_top(int i, double const M[XY][4], + double lambda[XY]) +{ + return M[i][0] * lambda[i - X] + M[i][1] * lambda[i + 1] + + M[i][3] * lambda[i - 1]; +} +static double compute_lambda_top_end(int i, double const M[XY][4], + double lambda[XY]) +{ + return M[i][0] * lambda[i - X] + M[i][3] * lambda[i - 1]; +} + +// Gauss-Seidel iteration with over-relaxation. +static double gauss_seidel2_SOR(double const M[XY][4], double omega, + double lambda[XY]) +{ + double old_lambda[XY]; + for (int i = 0; i < XY; i++) + old_lambda[i] = lambda[i]; + int i; + lambda[0] = compute_lambda_bottom_start(0, M, lambda); + for (i = 1; i < X; i++) + lambda[i] = compute_lambda_bottom(i, M, lambda); + for (; i < XY - X; i++) + lambda[i] = compute_lambda_interior(i, M, lambda); + for (; i < XY - 1; i++) + lambda[i] = compute_lambda_top(i, M, lambda); + lambda[i] = compute_lambda_top_end(i, M, lambda); + // Also solve the system from bottom to top, to help spread the updates + // better. + lambda[i] = compute_lambda_top_end(i, M, lambda); + for (i = XY - 2; i >= XY - X; i--) + lambda[i] = compute_lambda_top(i, M, lambda); + for (; i >= X; i--) + lambda[i] = compute_lambda_interior(i, M, lambda); + for (; i >= 1; i--) + lambda[i] = compute_lambda_bottom(i, M, lambda); + lambda[0] = compute_lambda_bottom_start(0, M, lambda); + double max_diff = 0; + for (int i = 0; i < XY; i++) { + lambda[i] = old_lambda[i] + (lambda[i] - old_lambda[i]) * omega; + if (fabs(lambda[i] - old_lambda[i]) > fabs(max_diff)) + max_diff = lambda[i] - old_lambda[i]; + } + return max_diff; +} + +// Normalise the values so that the smallest value is 1. +static void normalise(double *ptr, size_t n) +{ + double minval = ptr[0]; + for (size_t i = 1; i < n; i++) + minval = std::min(minval, ptr[i]); + for (size_t i = 0; i < n; i++) + ptr[i] /= minval; +} + +static void run_matrix_iterations(double const C[XY], double lambda[XY], + double const W[XY][4], double omega, + int n_iter, double threshold) +{ + double M[XY][4]; + construct_M(C, W, M); + double last_max_diff = std::numeric_limits<double>::max(); + for (int i = 0; i < n_iter; i++) { + double max_diff = fabs(gauss_seidel2_SOR(M, omega, lambda)); + if (max_diff < threshold) { + RPI_LOG("Stop after " << i + 1 << " iterations"); + break; + } + // this happens very occasionally (so make a note), though + // doesn't seem to matter + if (max_diff > last_max_diff) + RPI_LOG("Iteration " << i << ": max_diff gone up " + << last_max_diff << " to " + << max_diff); + last_max_diff = max_diff; + } + // We're going to normalise the lambdas so the smallest is 1. Not sure + // this is really necessary as they get renormalised later, but I + // suppose it does stop these quantities from wandering off... + normalise(lambda, XY); +} + +static void add_luminance_rb(double result[XY], double const lambda[XY], + double const luminance_lut[XY], + double luminance_strength) +{ + for (int i = 0; i < XY; i++) + result[i] = lambda[i] * + ((luminance_lut[i] - 1) * luminance_strength + 1); +} + +static void add_luminance_g(double result[XY], double lambda, + double const luminance_lut[XY], + double luminance_strength) +{ + for (int i = 0; i < XY; i++) + result[i] = lambda * + ((luminance_lut[i] - 1) * luminance_strength + 1); +} + +void add_luminance_to_tables(double results[3][Y][X], double const lambda_r[XY], + double lambda_g, double const lambda_b[XY], + double const luminance_lut[XY], + double luminance_strength) +{ + add_luminance_rb((double *)results[0], lambda_r, luminance_lut, + luminance_strength); + add_luminance_g((double *)results[1], lambda_g, luminance_lut, + luminance_strength); + add_luminance_rb((double *)results[2], lambda_b, luminance_lut, + luminance_strength); + normalise((double *)results, 3 * XY); +} + +void Alsc::doAlsc() +{ + double Cr[XY], Cb[XY], Wr[XY][4], Wb[XY][4], cal_table_r[XY], + cal_table_b[XY], cal_table_tmp[XY]; + // Calculate our R/B ("Cr"/"Cb") colour statistics, and assess which are + // usable. + calculate_Cr_Cb(statistics_, Cr, Cb, config_.min_count, config_.min_G); + // Fetch the new calibrations (if any) for this CT. Resample them in + // case the camera mode is not full-frame. + get_cal_table(ct_, config_.calibrations_Cr, cal_table_tmp); + resample_cal_table(cal_table_tmp, async_camera_mode_, cal_table_r); + get_cal_table(ct_, config_.calibrations_Cb, cal_table_tmp); + resample_cal_table(cal_table_tmp, async_camera_mode_, cal_table_b); + // You could print out the cal tables for this image here, if you're + // tuning the algorithm... + (void)print_cal_table; + // Apply any calibration to the statistics, so the adaptive algorithm + // makes only the extra adjustments. + apply_cal_table(cal_table_r, Cr); + apply_cal_table(cal_table_b, Cb); + // Compute weights between zones. + compute_W(Cr, config_.sigma_Cr, Wr); + compute_W(Cb, config_.sigma_Cb, Wb); + // Run Gauss-Seidel iterations over the resulting matrix, for R and B. + run_matrix_iterations(Cr, lambda_r_, Wr, config_.omega, config_.n_iter, + config_.threshold); + run_matrix_iterations(Cb, lambda_b_, Wb, config_.omega, config_.n_iter, + config_.threshold); + // Fold the calibrated gains into our final lambda values. (Note that on + // the next run, we re-start with the lambda values that don't have the + // calibration gains included.) + compensate_lambdas_for_cal(cal_table_r, lambda_r_, async_lambda_r_); + compensate_lambdas_for_cal(cal_table_b, lambda_b_, async_lambda_b_); + // Fold in the luminance table at the appropriate strength. + add_luminance_to_tables(async_results_, async_lambda_r_, 1.0, + async_lambda_b_, config_.luminance_lut, + config_.luminance_strength); +} + +// Register algorithm with the system. +static Algorithm *Create(Controller *controller) +{ + return (Algorithm *)new Alsc(controller); +} +static RegisterAlgorithm reg(NAME, &Create); |