diff options
Diffstat (limited to 'src/ipa/rpi/controller')
| -rw-r--r-- | src/ipa/rpi/controller/rpi/hdr.cpp | 112 | ||||
| -rw-r--r-- | src/ipa/rpi/controller/rpi/hdr.h | 10 |
2 files changed, 105 insertions, 17 deletions
diff --git a/src/ipa/rpi/controller/rpi/hdr.cpp b/src/ipa/rpi/controller/rpi/hdr.cpp index 0019d508..34cf360e 100644 --- a/src/ipa/rpi/controller/rpi/hdr.cpp +++ b/src/ipa/rpi/controller/rpi/hdr.cpp @@ -7,6 +7,8 @@ #include "hdr.h" +#include <cmath> + #include <libcamera/base/log.h> #include "../agc_status.h" @@ -39,25 +41,52 @@ void HdrConfig::read(const libcamera::YamlObject ¶ms, const std::string &mod channelMap[v.get<unsigned int>().value()] = k; /* Lens shading related parameters. */ - if (params.contains("spatial_gain")) { - spatialGain.read(params["spatial_gain"]); - diffusion = params["diffusion"].get<unsigned int>(3); - /* Clip to an arbitrary limit just to stop typos from killing the system! */ - const unsigned int MAX_DIFFUSION = 15; - if (diffusion > MAX_DIFFUSION) { - diffusion = MAX_DIFFUSION; - LOG(RPiHdr, Warning) << "Diffusion value clipped to " << MAX_DIFFUSION; - } + if (params.contains("spatial_gain_curve")) { + spatialGainCurve.read(params["spatial_gain_curve"]); + } else if (params.contains("spatial_gain")) { + double spatialGain = params["spatial_gain"].get<double>(2.0); + spatialGainCurve.append(0.0, spatialGain); + spatialGainCurve.append(0.01, spatialGain); + spatialGainCurve.append(0.06, 1.0); /* maybe make this programmable? */ + spatialGainCurve.append(1.0, 1.0); + } + + diffusion = params["diffusion"].get<unsigned int>(3); + /* Clip to an arbitrary limit just to stop typos from killing the system! */ + const unsigned int MAX_DIFFUSION = 15; + if (diffusion > MAX_DIFFUSION) { + diffusion = MAX_DIFFUSION; + LOG(RPiHdr, Warning) << "Diffusion value clipped to " << MAX_DIFFUSION; } /* Read any tonemap parameters. */ tonemapEnable = params["tonemap_enable"].get<int>(0); - detailConstant = params["detail_constant"].get<uint16_t>(50); - detailSlope = params["detail_slope"].get<double>(8.0); + detailConstant = params["detail_constant"].get<uint16_t>(0); + detailSlope = params["detail_slope"].get<double>(0.0); iirStrength = params["iir_strength"].get<double>(8.0); strength = params["strength"].get<double>(1.5); if (tonemapEnable) tonemap.read(params["tonemap"]); + speed = params["speed"].get<double>(1.0); + if (params.contains("hi_quantile_targets")) { + hiQuantileTargets = params["hi_quantile_targets"].getList<double>().value(); + if (hiQuantileTargets.empty() || hiQuantileTargets.size() % 2) + LOG(RPiHdr, Fatal) << "hi_quantile_targets much be even and non-empty"; + } else + hiQuantileTargets = { 0.95, 0.65, 0.5, 0.28, 0.3, 0.25 }; + hiQuantileMaxGain = params["hi_quantile_max_gain"].get<double>(1.6); + if (params.contains("quantile_targets")) { + quantileTargets = params["quantile_targets"].getList<double>().value(); + if (quantileTargets.empty() || quantileTargets.size() % 2) + LOG(RPiHdr, Fatal) << "quantile_targets much be even and non-empty"; + } else + quantileTargets = { 0.2, 0.03, 1.0, 0.15 }; + powerMin = params["power_min"].get<double>(0.65); + powerMax = params["power_max"].get<double>(1.0); + if (params.contains("contrast_adjustments")) { + contrastAdjustments = params["contrast_adjustments"].getList<double>().value(); + } else + contrastAdjustments = { 0.5, 0.75 }; /* Read any stitch parameters. */ stitchEnable = params["stitch_enable"].get<int>(0); @@ -159,7 +188,7 @@ void Hdr::prepare(Metadata *imageMetadata) } HdrConfig &config = it->second; - if (config.spatialGain.empty()) + if (config.spatialGainCurve.empty()) return; AlscStatus alscStatus{}; /* some compilers seem to require the braces */ @@ -205,10 +234,61 @@ bool Hdr::updateTonemap([[maybe_unused]] StatisticsPtr &stats, HdrConfig &config return true; /* - * If we wanted to build or adjust tonemaps dynamically, this would be the place - * to do it. But for now we seem to be getting by without. + * Create a tonemap dynamically. We have three ingredients. + * + * 1. We have a list of "hi quantiles" and "targets". We use these to judge if + * the image does seem to be reasonably saturated. If it isn't, we calculate + * a gain that we will feed as a linear factor into the tonemap generation. + * This prevents unsaturated images from beoming quite so "flat". + * + * 2. We have a list of quantile/target pairs for the bottom of the histogram. + * We use these to calculate how much gain we must apply to the bottom of the + * tonemap. We apply this gain as a power curve so as not to blow out the top + * end. + * + * 3. Finally, when we generate the tonemap, we have some contrast adjustments + * for the bottom because we know that power curves can start quite steeply and + * cause a washed-out look. */ + /* Compute the linear gain from the headroom for saturation at the top. */ + double gain = 10; /* arbitrary, but hiQuantileMaxGain will clamp it later */ + for (unsigned int i = 0; i < config.hiQuantileTargets.size(); i += 2) { + double quantile = config.hiQuantileTargets[i]; + double target = config.hiQuantileTargets[i + 1]; + double value = stats->yHist.interQuantileMean(quantile, 1.0) / 1024.0; + double newGain = target / (value + 0.01); + gain = std::min(gain, newGain); + } + gain = std::clamp(gain, 1.0, config.hiQuantileMaxGain); + + /* Compute the power curve from the amount of gain needed at the bottom. */ + double min_power = 2; /* arbitrary, but config.powerMax will clamp it later */ + for (unsigned int i = 0; i < config.quantileTargets.size(); i += 2) { + double quantile = config.quantileTargets[i]; + double target = config.quantileTargets[i + 1]; + double value = stats->yHist.interQuantileMean(0, quantile) / 1024.0; + value = std::min(value * gain, 1.0); + double power = log(target + 1e-6) / log(value + 1e-6); + min_power = std::min(min_power, power); + } + double power = std::clamp(min_power, config.powerMin, config.powerMax); + + /* Generate the tonemap, including the contrast adjustment factors. */ + Pwl tonemap; + tonemap.append(0, 0); + for (unsigned int i = 0; i <= 6; i++) { + double x = 1 << (i + 9); /* x loops from 512 to 32768 inclusive */ + double y = pow(std::min(x * gain, 65535.0) / 65536.0, power) * 65536; + if (i < config.contrastAdjustments.size()) + y *= config.contrastAdjustments[i]; + if (!tonemap_.empty()) + y = y * config.speed + tonemap_.eval(x) * (1 - config.speed); + tonemap.append(x, y); + } + tonemap.append(65535, 65535); + tonemap_ = tonemap; + return true; } @@ -255,7 +335,7 @@ static void averageGains(std::vector<double> &src, std::vector<double> &dst, con void Hdr::updateGains(StatisticsPtr &stats, HdrConfig &config) { - if (config.spatialGain.empty()) + if (config.spatialGainCurve.empty()) return; /* When alternating exposures, only compute these gains for the short frame. */ @@ -270,7 +350,7 @@ void Hdr::updateGains(StatisticsPtr &stats, HdrConfig &config) double g = region.val.gSum / counted; double b = region.val.bSum / counted; double brightness = std::max({ r, g, b }) / 65535; - gains_[0][i] = config.spatialGain.eval(brightness); + gains_[0][i] = config.spatialGainCurve.eval(brightness); } /* Ping-pong between the two gains_ buffers. */ diff --git a/src/ipa/rpi/controller/rpi/hdr.h b/src/ipa/rpi/controller/rpi/hdr.h index 44272cb8..9b7327f8 100644 --- a/src/ipa/rpi/controller/rpi/hdr.h +++ b/src/ipa/rpi/controller/rpi/hdr.h @@ -26,7 +26,7 @@ struct HdrConfig { std::map<unsigned int, std::string> channelMap; /* Lens shading related parameters. */ - Pwl spatialGain; /* Brightness to gain curve for different image regions. */ + Pwl spatialGainCurve; /* Brightness to gain curve for different image regions. */ unsigned int diffusion; /* How much to diffuse the gain spatially. */ /* Tonemap related parameters. */ @@ -36,6 +36,14 @@ struct HdrConfig { double iirStrength; double strength; Pwl tonemap; + /* These relate to adaptive tonemap calculation. */ + double speed; + std::vector<double> hiQuantileTargets; /* quantiles to check for unsaturated images */ + double hiQuantileMaxGain; /* the max gain we'll apply when unsaturated */ + std::vector<double> quantileTargets; /* target values for histogram quantiles */ + double powerMin; /* minimum tonemap power */ + double powerMax; /* maximum tonemap power */ + std::vector<double> contrastAdjustments; /* any contrast adjustment factors */ /* Stitch related parameters. */ bool stitchEnable; |