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-rw-r--r--src/ipa/ipu3/algorithms/awb.cpp341
-rw-r--r--src/ipa/ipu3/algorithms/awb.h91
-rw-r--r--src/ipa/ipu3/algorithms/meson.build1
3 files changed, 433 insertions, 0 deletions
diff --git a/src/ipa/ipu3/algorithms/awb.cpp b/src/ipa/ipu3/algorithms/awb.cpp
new file mode 100644
index 00000000..e15f7406
--- /dev/null
+++ b/src/ipa/ipu3/algorithms/awb.cpp
@@ -0,0 +1,341 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2021, Ideas On Board
+ *
+ * awb.cpp - AWB control algorithm
+ */
+#include "awb.h"
+
+#include <algorithm>
+#include <cmath>
+
+#include <libcamera/base/log.h>
+
+namespace libcamera {
+
+namespace ipa::ipu3::algorithms {
+
+LOG_DEFINE_CATEGORY(IPU3Awb)
+
+static constexpr uint32_t kMinZonesCounted = 16;
+static constexpr uint32_t kMinGreenLevelInZone = 32;
+
+/**
+ * \struct IspStatsRegion
+ * \brief RGB statistics for a given region
+ *
+ * The IspStatsRegion structure is intended to abstract the ISP specific
+ * statistics and use an agnostic algorithm to compute AWB.
+ *
+ * \var IspStatsRegion::counted
+ * \brief Number of pixels used to calculate the sums
+ *
+ * \var IspStatsRegion::uncounted
+ * \brief Remaining number of pixels in the region
+ *
+ * \var IspStatsRegion::rSum
+ * \brief Sum of the red values in the region
+ *
+ * \var IspStatsRegion::gSum
+ * \brief Sum of the green values in the region
+ *
+ * \var IspStatsRegion::bSum
+ * \brief Sum of the blue values in the region
+ */
+
+/**
+ * \struct AwbStatus
+ * \brief AWB parameters calculated
+ *
+ * The AwbStatus structure is intended to store the AWB
+ * parameters calculated by the algorithm
+ *
+ * \var AwbStatus::temperatureK
+ * \brief Color temperature calculated
+ *
+ * \var AwbStatus::redGain
+ * \brief Gain calculated for the red channel
+ *
+ * \var AwbStatus::greenGain
+ * \brief Gain calculated for the green channel
+ *
+ * \var AwbStatus::blueGain
+ * \brief Gain calculated for the blue channel
+ */
+
+/**
+ * \struct Ipu3AwbCell
+ * \brief Memory layout for each cell in AWB metadata
+ *
+ * The Ipu3AwbCell structure is used to get individual values
+ * such as red average or saturation ratio in a particular cell.
+ *
+ * \var Ipu3AwbCell::greenRedAvg
+ * \brief Green average for red lines in the cell
+ *
+ * \var Ipu3AwbCell::redAvg
+ * \brief Red average in the cell
+ *
+ * \var Ipu3AwbCell::blueAvg
+ * \brief blue average in the cell
+ *
+ * \var Ipu3AwbCell::greenBlueAvg
+ * \brief Green average for blue lines
+ *
+ * \var Ipu3AwbCell::satRatio
+ * \brief Saturation ratio in the cell
+ *
+ * \var Ipu3AwbCell::padding
+ * \brief array of unused bytes for padding
+ */
+
+/* Default settings for Bayer noise reduction replicated from the Kernel */
+static const struct ipu3_uapi_bnr_static_config imguCssBnrDefaults = {
+ .wb_gains = { 16, 16, 16, 16 },
+ .wb_gains_thr = { 255, 255, 255, 255 },
+ .thr_coeffs = { 1700, 0, 31, 31, 0, 16 },
+ .thr_ctrl_shd = { 26, 26, 26, 26 },
+ .opt_center = { -648, 0, -366, 0 },
+ .lut = {
+ { 17, 23, 28, 32, 36, 39, 42, 45,
+ 48, 51, 53, 55, 58, 60, 62, 64,
+ 66, 68, 70, 72, 73, 75, 77, 78,
+ 80, 82, 83, 85, 86, 88, 89, 90 } },
+ .bp_ctrl = { 20, 0, 1, 40, 0, 6, 0, 6, 0 },
+ .dn_detect_ctrl = { 9, 3, 4, 0, 8, 0, 1, 1, 1, 1, 0 },
+ .column_size = 1296,
+ .opt_center_sqr = { 419904, 133956 },
+};
+
+/* Default color correction matrix defined as an identity matrix */
+static const struct ipu3_uapi_ccm_mat_config imguCssCcmDefault = {
+ 8191, 0, 0, 0,
+ 0, 8191, 0, 0,
+ 0, 0, 8191, 0
+};
+
+Awb::Awb()
+ : Algorithm()
+{
+ asyncResults_.blueGain = 1.0;
+ asyncResults_.greenGain = 1.0;
+ asyncResults_.redGain = 1.0;
+ asyncResults_.temperatureK = 4500;
+
+ zones_.reserve(kAwbStatsSizeX * kAwbStatsSizeY);
+}
+
+Awb::~Awb() = default;
+
+/**
+ * The function estimates the correlated color temperature using
+ * from RGB color space input.
+ * In physics and color science, the Planckian locus or black body locus is
+ * the path or locus that the color of an incandescent black body would take
+ * in a particular chromaticity space as the blackbody temperature changes.
+ *
+ * If a narrow range of color temperatures is considered (those encapsulating
+ * daylight being the most practical case) one can approximate the Planckian
+ * locus in order to calculate the CCT in terms of chromaticity coordinates.
+ *
+ * More detailed information can be found in:
+ * https://en.wikipedia.org/wiki/Color_temperature#Approximation
+ */
+uint32_t Awb::estimateCCT(double red, double green, double blue)
+{
+ /* Convert the RGB values to CIE tristimulus values (XYZ) */
+ double X = (-0.14282) * (red) + (1.54924) * (green) + (-0.95641) * (blue);
+ double Y = (-0.32466) * (red) + (1.57837) * (green) + (-0.73191) * (blue);
+ double Z = (-0.68202) * (red) + (0.77073) * (green) + (0.56332) * (blue);
+
+ /* Calculate the normalized chromaticity values */
+ double x = X / (X + Y + Z);
+ double y = Y / (X + Y + Z);
+
+ /* Calculate CCT */
+ double n = (x - 0.3320) / (0.1858 - y);
+ return 449 * n * n * n + 3525 * n * n + 6823.3 * n + 5520.33;
+}
+
+/* Generate an RGB vector with the average values for each region */
+void Awb::generateZones(std::vector<RGB> &zones)
+{
+ for (unsigned int i = 0; i < kAwbStatsSizeX * kAwbStatsSizeY; i++) {
+ RGB zone;
+ double counted = awbStats_[i].counted;
+ if (counted >= kMinZonesCounted) {
+ zone.G = awbStats_[i].gSum / counted;
+ if (zone.G >= kMinGreenLevelInZone) {
+ zone.R = awbStats_[i].rSum / counted;
+ zone.B = awbStats_[i].bSum / counted;
+ zones.push_back(zone);
+ }
+ }
+ }
+}
+
+/* Translate the IPU3 statistics into the default statistics region array */
+void Awb::generateAwbStats(const ipu3_uapi_stats_3a *stats)
+{
+ uint32_t regionWidth = round(awbGrid_.width / static_cast<double>(kAwbStatsSizeX));
+ uint32_t regionHeight = round(awbGrid_.height / static_cast<double>(kAwbStatsSizeY));
+
+ /*
+ * Generate a (kAwbStatsSizeX x kAwbStatsSizeY) array from the IPU3 grid which is
+ * (awbGrid_.width x awbGrid_.height).
+ */
+ for (unsigned int j = 0; j < kAwbStatsSizeY * regionHeight; j++) {
+ for (unsigned int i = 0; i < kAwbStatsSizeX * regionWidth; i++) {
+ uint32_t cellPosition = j * awbGrid_.width + i;
+ uint32_t cellX = (cellPosition / regionWidth) % kAwbStatsSizeX;
+ uint32_t cellY = ((cellPosition / awbGrid_.width) / regionHeight) % kAwbStatsSizeY;
+
+ uint32_t awbRegionPosition = cellY * kAwbStatsSizeX + cellX;
+ cellPosition *= 8;
+
+ /* Cast the initial IPU3 structure to simplify the reading */
+ Ipu3AwbCell *currentCell = reinterpret_cast<Ipu3AwbCell *>(const_cast<uint8_t *>(&stats->awb_raw_buffer.meta_data[cellPosition]));
+ if (currentCell->satRatio == 0) {
+ /* The cell is not saturated, use the current cell */
+ awbStats_[awbRegionPosition].counted++;
+ uint32_t greenValue = currentCell->greenRedAvg + currentCell->greenBlueAvg;
+ awbStats_[awbRegionPosition].gSum += greenValue / 2;
+ awbStats_[awbRegionPosition].rSum += currentCell->redAvg;
+ awbStats_[awbRegionPosition].bSum += currentCell->blueAvg;
+ }
+ }
+ }
+}
+
+void Awb::clearAwbStats()
+{
+ for (unsigned int i = 0; i < kAwbStatsSizeX * kAwbStatsSizeY; i++) {
+ awbStats_[i].bSum = 0;
+ awbStats_[i].rSum = 0;
+ awbStats_[i].gSum = 0;
+ awbStats_[i].counted = 0;
+ awbStats_[i].uncounted = 0;
+ }
+}
+
+void Awb::awbGreyWorld()
+{
+ LOG(IPU3Awb, Debug) << "Grey world AWB";
+ /*
+ * Make a separate list of the derivatives for each of red and blue, so
+ * that we can sort them to exclude the extreme gains. We could
+ * consider some variations, such as normalising all the zones first, or
+ * doing an L2 average etc.
+ */
+ std::vector<RGB> &redDerivative(zones_);
+ std::vector<RGB> blueDerivative(redDerivative);
+ std::sort(redDerivative.begin(), redDerivative.end(),
+ [](RGB const &a, RGB const &b) {
+ return a.G * b.R < b.G * a.R;
+ });
+ std::sort(blueDerivative.begin(), blueDerivative.end(),
+ [](RGB const &a, RGB const &b) {
+ return a.G * b.B < b.G * a.B;
+ });
+
+ /* Average the middle half of the values. */
+ int discard = redDerivative.size() / 4;
+
+ RGB sumRed(0, 0, 0);
+ RGB sumBlue(0, 0, 0);
+ for (auto ri = redDerivative.begin() + discard,
+ bi = blueDerivative.begin() + discard;
+ ri != redDerivative.end() - discard; ri++, bi++)
+ sumRed += *ri, sumBlue += *bi;
+
+ double redGain = sumRed.G / (sumRed.R + 1),
+ blueGain = sumBlue.G / (sumBlue.B + 1);
+
+ /* Color temperature is not relevant in Grey world but still useful to estimate it :-) */
+ asyncResults_.temperatureK = estimateCCT(sumRed.R, sumRed.G, sumBlue.B);
+ asyncResults_.redGain = redGain;
+ asyncResults_.greenGain = 1.0;
+ asyncResults_.blueGain = blueGain;
+}
+
+void Awb::calculateWBGains(const ipu3_uapi_stats_3a *stats)
+{
+ ASSERT(stats->stats_3a_status.awb_en);
+ zones_.clear();
+ clearAwbStats();
+ generateAwbStats(stats);
+ generateZones(zones_);
+ LOG(IPU3Awb, Debug) << "Valid zones: " << zones_.size();
+ if (zones_.size() > 10) {
+ awbGreyWorld();
+ LOG(IPU3Awb, Debug) << "Gain found for red: " << asyncResults_.redGain
+ << " and for blue: " << asyncResults_.blueGain;
+ }
+}
+
+void Awb::process(IPAContext &context, const ipu3_uapi_stats_3a *stats)
+{
+ calculateWBGains(stats);
+
+ /*
+ * Gains are only recalculated if enough zones were detected.
+ * The results are cached, so if no results were calculated, we set the
+ * cached values from asyncResults_ here.
+ */
+ context.frameContext.awb.gains.blue = asyncResults_.blueGain;
+ context.frameContext.awb.gains.green = asyncResults_.greenGain;
+ context.frameContext.awb.gains.red = asyncResults_.redGain;
+}
+
+void Awb::prepare(IPAContext &context, ipu3_uapi_params *params)
+{
+ params->acc_param.awb.config.rgbs_thr_gr = 8191;
+ params->acc_param.awb.config.rgbs_thr_r = 8191;
+ params->acc_param.awb.config.rgbs_thr_gb = 8191;
+ params->acc_param.awb.config.rgbs_thr_b = IPU3_UAPI_AWB_RGBS_THR_B_INCL_SAT
+ | IPU3_UAPI_AWB_RGBS_THR_B_EN
+ | 8191;
+
+ awbGrid_ = context.configuration.grid.bdsGrid;
+
+ params->acc_param.awb.config.grid = context.configuration.grid.bdsGrid;
+
+ /*
+ * Optical center is column start (respectively row start) of the
+ * region of interest minus its X center (respectively Y center).
+ *
+ * For the moment use BDS as a first approximation, but it should
+ * be calculated based on Shading (SHD) parameters.
+ */
+ params->acc_param.bnr = imguCssBnrDefaults;
+ Size &bdsOutputSize = context.configuration.grid.bdsOutputSize;
+ params->acc_param.bnr.column_size = bdsOutputSize.width;
+ params->acc_param.bnr.opt_center.x_reset = awbGrid_.x_start - (bdsOutputSize.width / 2);
+ params->acc_param.bnr.opt_center.y_reset = awbGrid_.y_start - (bdsOutputSize.height / 2);
+ params->acc_param.bnr.opt_center_sqr.x_sqr_reset = params->acc_param.bnr.opt_center.x_reset
+ * params->acc_param.bnr.opt_center.x_reset;
+ params->acc_param.bnr.opt_center_sqr.y_sqr_reset = params->acc_param.bnr.opt_center.y_reset
+ * params->acc_param.bnr.opt_center.y_reset;
+ /*
+ * Green gains should not be touched and considered 1.
+ * Default is 16, so do not change it at all.
+ * 4096 is the value for a gain of 1.0
+ */
+ params->acc_param.bnr.wb_gains.gr = 16 * context.frameContext.awb.gains.green;
+ params->acc_param.bnr.wb_gains.r = 4096 * context.frameContext.awb.gains.red;
+ params->acc_param.bnr.wb_gains.b = 4096 * context.frameContext.awb.gains.blue;
+ params->acc_param.bnr.wb_gains.gb = 16 * context.frameContext.awb.gains.green;
+
+ LOG(IPU3Awb, Debug) << "Color temperature estimated: " << asyncResults_.temperatureK;
+
+ /* The CCM matrix may change when color temperature will be used */
+ params->acc_param.ccm = imguCssCcmDefault;
+
+ params->use.acc_awb = 1;
+ params->use.acc_bnr = 1;
+ params->use.acc_ccm = 1;
+}
+
+} /* namespace ipa::ipu3::algorithms */
+
+} /* namespace libcamera */
diff --git a/src/ipa/ipu3/algorithms/awb.h b/src/ipa/ipu3/algorithms/awb.h
new file mode 100644
index 00000000..fac54e45
--- /dev/null
+++ b/src/ipa/ipu3/algorithms/awb.h
@@ -0,0 +1,91 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2021, Ideas On Board
+ *
+ * awb.h - IPU3 AWB control algorithm
+ */
+#ifndef __LIBCAMERA_IPU3_ALGORITHMS_AWB_H__
+#define __LIBCAMERA_IPU3_ALGORITHMS_AWB_H__
+
+#include <vector>
+
+#include <linux/intel-ipu3.h>
+
+#include <libcamera/geometry.h>
+
+#include "algorithm.h"
+
+namespace libcamera {
+
+namespace ipa::ipu3::algorithms {
+
+/* Region size for the statistics generation algorithm */
+static constexpr uint32_t kAwbStatsSizeX = 16;
+static constexpr uint32_t kAwbStatsSizeY = 12;
+
+class Awb : public Algorithm
+{
+public:
+ Awb();
+ ~Awb();
+
+ void prepare(IPAContext &context, ipu3_uapi_params *params) override;
+ void process(IPAContext &context, const ipu3_uapi_stats_3a *stats) override;
+
+ struct Ipu3AwbCell {
+ unsigned char greenRedAvg;
+ unsigned char redAvg;
+ unsigned char blueAvg;
+ unsigned char greenBlueAvg;
+ unsigned char satRatio;
+ unsigned char padding[3];
+ } __attribute__((packed));
+
+ /* \todo Make these three structs available to all the ISPs ? */
+ struct RGB {
+ RGB(double _R = 0, double _G = 0, double _B = 0)
+ : R(_R), G(_G), B(_B)
+ {
+ }
+ double R, G, B;
+ RGB &operator+=(RGB const &other)
+ {
+ R += other.R, G += other.G, B += other.B;
+ return *this;
+ }
+ };
+
+ struct IspStatsRegion {
+ unsigned int counted;
+ unsigned int uncounted;
+ unsigned long long rSum;
+ unsigned long long gSum;
+ unsigned long long bSum;
+ };
+
+ struct AwbStatus {
+ double temperatureK;
+ double redGain;
+ double greenGain;
+ double blueGain;
+ };
+
+private:
+ void calculateWBGains(const ipu3_uapi_stats_3a *stats);
+ void generateZones(std::vector<RGB> &zones);
+ void generateAwbStats(const ipu3_uapi_stats_3a *stats);
+ void clearAwbStats();
+ void awbGreyWorld();
+ uint32_t estimateCCT(double red, double green, double blue);
+
+ struct ipu3_uapi_grid_config awbGrid_;
+
+ std::vector<RGB> zones_;
+ IspStatsRegion awbStats_[kAwbStatsSizeX * kAwbStatsSizeY];
+ AwbStatus asyncResults_;
+};
+
+} /* namespace ipa::ipu3::algorithms */
+
+} /* namespace libcamera*/
+#endif /* __LIBCAMERA_IPU3_ALGORITHMS_AWB_H__ */
diff --git a/src/ipa/ipu3/algorithms/meson.build b/src/ipa/ipu3/algorithms/meson.build
index 71eedfa4..fa004df4 100644
--- a/src/ipa/ipu3/algorithms/meson.build
+++ b/src/ipa/ipu3/algorithms/meson.build
@@ -2,5 +2,6 @@
ipu3_ipa_algorithms = files([
'algorithm.cpp',
+ 'awb.cpp',
'tone_mapping.cpp',
])
generated by cgit v1.2.1 (git 2.18.0) at 2024-11-04 20:44:56 +0000