summaryrefslogtreecommitdiff
path: root/src/ipa/rpi/controller/rpi/hdr.cpp
diff options
context:
space:
mode:
Diffstat (limited to 'src/ipa/rpi/controller/rpi/hdr.cpp')
-rw-r--r--src/ipa/rpi/controller/rpi/hdr.cpp114
1 files changed, 97 insertions, 17 deletions
diff --git a/src/ipa/rpi/controller/rpi/hdr.cpp b/src/ipa/rpi/controller/rpi/hdr.cpp
index fb580548..34cf360e 100644
--- a/src/ipa/rpi/controller/rpi/hdr.cpp
+++ b/src/ipa/rpi/controller/rpi/hdr.cpp
@@ -2,11 +2,13 @@
/*
* Copyright (C) 2023 Raspberry Pi Ltd
*
- * hdr.cpp - HDR control algorithm
+ * HDR control algorithm
*/
#include "hdr.h"
+#include <cmath>
+
#include <libcamera/base/log.h>
#include "../agc_status.h"
@@ -39,25 +41,52 @@ void HdrConfig::read(const libcamera::YamlObject &params, 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. */
generated by cgit v1.2.1 (git 2.18.0) at 2024-05-20 12:51:27 +0000