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Diffstat (limited to 'src/ipa/ipu3/ipu3_awb.cpp')
| -rw-r--r-- | src/ipa/ipu3/ipu3_awb.cpp | 356 |
1 files changed, 356 insertions, 0 deletions
diff --git a/src/ipa/ipu3/ipu3_awb.cpp b/src/ipa/ipu3/ipu3_awb.cpp new file mode 100644 index 00000000..060d1e18 --- /dev/null +++ b/src/ipa/ipu3/ipu3_awb.cpp @@ -0,0 +1,356 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ +/* + * Copyright (C) 2021, Ideas On Board + * + * ipu3_awb.cpp - AWB control algorithm + */ +#include "ipu3_awb.h" + +#include <cmath> +#include <numeric> +#include <unordered_map> + +#include "libcamera/internal/log.h" + +namespace libcamera { + +namespace ipa::ipu3 { + +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 settings for Auto White Balance replicated from the Kernel*/ +static const struct ipu3_uapi_awb_config_s imguCssAwbDefaults = { + .rgbs_thr_gr = 8191, + .rgbs_thr_r = 8191, + .rgbs_thr_gb = 8191, + .rgbs_thr_b = 8191 | IPU3_UAPI_AWB_RGBS_THR_B_EN | IPU3_UAPI_AWB_RGBS_THR_B_INCL_SAT, + .grid = { + .width = 160, + .height = 36, + .block_width_log2 = 3, + .block_height_log2 = 4, + .height_per_slice = 1, /* Overridden by kernel. */ + .x_start = 0, + .y_start = 0, + .x_end = 0, + .y_end = 0, + }, +}; + +/* 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 +}; + +IPU3Awb::IPU3Awb() + : Algorithm() +{ + asyncResults_.blueGain = 1.0; + asyncResults_.greenGain = 1.0; + asyncResults_.redGain = 1.0; + asyncResults_.temperatureK = 4500; +} + +IPU3Awb::~IPU3Awb() +{ +} + +void IPU3Awb::initialise(ipu3_uapi_params ¶ms, const Size &bdsOutputSize, struct ipu3_uapi_grid_config &bdsGrid) +{ + params.use.acc_awb = 1; + params.acc_param.awb.config = imguCssAwbDefaults; + + awbGrid_ = bdsGrid; + params.acc_param.awb.config.grid = awbGrid_; + + params.use.acc_bnr = 1; + params.acc_param.bnr = imguCssBnrDefaults; + /** + * Optical center is column (respectively row) startminus X (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.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; + + params.use.acc_ccm = 1; + params.acc_param.ccm = imguCssCcmDefault; + + params.use.acc_gamma = 1; + params.acc_param.gamma.gc_ctrl.enable = 1; + + zones_.reserve(kAwbStatsSizeX * kAwbStatsSizeY); +} + +/** + * 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 IPU3Awb::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 IPU3Awb::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 IPU3Awb::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 IPU3Awb::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 IPU3Awb::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 IPU3Awb::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 IPU3Awb::updateWbParameters(ipu3_uapi_params ¶ms, double agcGamma) +{ + /* + * 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; + params.acc_param.bnr.wb_gains.r = 4096 * asyncResults_.redGain; + params.acc_param.bnr.wb_gains.b = 4096 * asyncResults_.blueGain; + params.acc_param.bnr.wb_gains.gb = 16; + + LOG(IPU3Awb, Debug) << "Color temperature estimated: " << asyncResults_.temperatureK + << " and gamma calculated: " << agcGamma; + + /* The CCM matrix may change when color temperature will be used */ + params.acc_param.ccm = imguCssCcmDefault; + + for (uint32_t i = 0; i < 256; i++) { + double j = i / 255.0; + double gamma = std::pow(j, 1.0 / agcGamma); + /* The maximum value 255 is represented on 13 bits in the IPU3 */ + params.acc_param.gamma.gc_lut.lut[i] = gamma * 8191; + } +} + +} /* namespace ipa::ipu3 */ + +} /* namespace libcamera */ |