From 61b43e50e76c16456b5d1873b6efd8aa0e848d6b Mon Sep 17 00:00:00 2001 From: Naushir Patuck Date: Fri, 3 Feb 2023 09:17:34 +0000 Subject: ipa: raspberrypi: Normalise region sums to 16-bits The VC4 ISP uses a pipeline bit-depth of 13-bits. The AGC algorithm needs to know this bit-depth when computing the Y value for the image. Instead of hardcoding the VC4 bit-depth in the AGC source code, normalise all region sums to 16-bits when filling the Statistics structure. AWB and ALSC are agnostic about pipeline depth, so do not need changing. Signed-off-by: Naushir Patuck Reviewed-by: David Plowman Reviewed-by: Kieran Bingham Signed-off-by: Kieran Bingham --- src/ipa/raspberrypi/controller/rpi/agc.cpp | 11 +++++------ src/ipa/raspberrypi/raspberrypi.cpp | 18 ++++++++++++------ 2 files changed, 17 insertions(+), 12 deletions(-) diff --git a/src/ipa/raspberrypi/controller/rpi/agc.cpp b/src/ipa/raspberrypi/controller/rpi/agc.cpp index 868c30f0..ea0c82b5 100644 --- a/src/ipa/raspberrypi/controller/rpi/agc.cpp +++ b/src/ipa/raspberrypi/controller/rpi/agc.cpp @@ -28,8 +28,6 @@ LOG_DEFINE_CATEGORY(RPiAgc) #define NAME "rpi.agc" -static constexpr unsigned int PipelineBits = 13; /* seems to be a 13-bit pipeline */ - int AgcMeteringMode::read(const libcamera::YamlObject ¶ms) { const YamlObject &yamlWeights = params["weights"]; @@ -586,6 +584,7 @@ void Agc::fetchAwbStatus(Metadata *imageMetadata) static double computeInitialY(StatisticsPtr &stats, AwbStatus const &awb, double weights[], double gain) { + constexpr unsigned int maxVal = 1 << Statistics::NormalisationFactorPow2; /* * Note how the calculation below means that equal weights give you * "average" metering (i.e. all pixels equally important). @@ -593,9 +592,9 @@ static double computeInitialY(StatisticsPtr &stats, AwbStatus const &awb, double rSum = 0, gSum = 0, bSum = 0, pixelSum = 0; for (unsigned int i = 0; i < stats->agcRegions.numRegions(); i++) { auto ®ion = stats->agcRegions.get(i); - double rAcc = std::min(region.val.rSum * gain, ((1 << PipelineBits) - 1) * region.counted); - double gAcc = std::min(region.val.gSum * gain, ((1 << PipelineBits) - 1) * region.counted); - double bAcc = std::min(region.val.bSum * gain, ((1 << PipelineBits) - 1) * region.counted); + double rAcc = std::min(region.val.rSum * gain, (maxVal - 1) * region.counted); + double gAcc = std::min(region.val.gSum * gain, (maxVal - 1) * region.counted); + double bAcc = std::min(region.val.bSum * gain, (maxVal - 1) * region.counted); rSum += rAcc * weights[i]; gSum += gAcc * weights[i]; bSum += bAcc * weights[i]; @@ -608,7 +607,7 @@ static double computeInitialY(StatisticsPtr &stats, AwbStatus const &awb, double ySum = rSum * awb.gainR * .299 + gSum * awb.gainG * .587 + bSum * awb.gainB * .114; - return ySum / pixelSum / (1 << PipelineBits); + return ySum / pixelSum / maxVal; } /* diff --git a/src/ipa/raspberrypi/raspberrypi.cpp b/src/ipa/raspberrypi/raspberrypi.cpp index 8c0df0ec..9b08ae4c 100644 --- a/src/ipa/raspberrypi/raspberrypi.cpp +++ b/src/ipa/raspberrypi/raspberrypi.cpp @@ -1377,11 +1377,17 @@ RPiController::StatisticsPtr IPARPi::fillStatistics(bcm2835_isp_stats *stats) co /* RGB histograms are not used, so do not populate them. */ statistics->yHist = RPiController::Histogram(stats->hist[0].g_hist, NUM_HISTOGRAM_BINS); + /* + * All region sums are based on a 13-bit pipeline bit-depth. Normalise + * this to 16-bits for the AGC/AWB/ALSC algorithms. + */ + constexpr unsigned int scale = Statistics::NormalisationFactorPow2 - 13; + statistics->awbRegions.init({ DEFAULT_AWB_REGIONS_X, DEFAULT_AWB_REGIONS_Y }); for (i = 0; i < statistics->awbRegions.numRegions(); i++) - statistics->awbRegions.set(i, { { stats->awb_stats[i].r_sum, - stats->awb_stats[i].g_sum, - stats->awb_stats[i].b_sum }, + statistics->awbRegions.set(i, { { stats->awb_stats[i].r_sum << scale, + stats->awb_stats[i].g_sum << scale, + stats->awb_stats[i].b_sum << scale }, stats->awb_stats[i].counted, stats->awb_stats[i].notcounted }); @@ -1391,9 +1397,9 @@ RPiController::StatisticsPtr IPARPi::fillStatistics(bcm2835_isp_stats *stats) co */ statistics->agcRegions.init(15); for (i = 0; i < statistics->agcRegions.numRegions(); i++) - statistics->agcRegions.set(i, { { stats->agc_stats[i].r_sum, - stats->agc_stats[i].g_sum, - stats->agc_stats[i].b_sum }, + statistics->agcRegions.set(i, { { stats->agc_stats[i].r_sum << scale, + stats->agc_stats[i].g_sum << scale, + stats->agc_stats[i].b_sum << scale }, stats->agc_stats[i].counted, stats->awb_stats[i].notcounted }); -- cgit v1.2.1