[PATCH 3/5] libcamera: software_isp: Move color mappings out of debayering
Milan Zamazal
mzamazal at redhat.com
Tue Apr 23 20:19:58 CEST 2024
Constructing the color mapping tables is related to stats rather than
debayering, where they are applied. Let's move the corresponding code
to stats processing.
This is a preliminary step towards building this functionality on top of
libipa/algorithm.h, which should follow.
Signed-off-by: Milan Zamazal <mzamazal at redhat.com>
---
.../internal/software_isp/debayer_params.h | 18 ++--
src/ipa/simple/soft_simple.cpp | 84 ++++++++++++-------
src/libcamera/software_isp/debayer.cpp | 29 ++++---
src/libcamera/software_isp/debayer_cpu.cpp | 41 ++-------
src/libcamera/software_isp/debayer_cpu.h | 9 +-
src/libcamera/software_isp/software_isp.cpp | 4 +-
6 files changed, 87 insertions(+), 98 deletions(-)
diff --git a/include/libcamera/internal/software_isp/debayer_params.h b/include/libcamera/internal/software_isp/debayer_params.h
index 32cd448a..09f4ff00 100644
--- a/include/libcamera/internal/software_isp/debayer_params.h
+++ b/include/libcamera/internal/software_isp/debayer_params.h
@@ -1,6 +1,6 @@
/* SPDX-License-Identifier: LGPL-2.1-or-later */
/*
- * Copyright (C) 2023, Red Hat Inc.
+ * Copyright (C) 2023, 2024 Red Hat Inc.
*
* Authors:
* Hans de Goede <hdegoede at redhat.com>
@@ -10,20 +10,20 @@
#pragma once
+#include <array>
+#include <stdint.h>
+
namespace libcamera {
struct DebayerParams {
static constexpr unsigned int kGain10 = 256;
+ static constexpr unsigned int kRGBLookupSize = 256;
- unsigned int gainR;
- unsigned int gainG;
- unsigned int gainB;
+ using ColorLookupTable = std::array<uint8_t, kRGBLookupSize>;
- float gamma;
- /**
- * \brief Level of the black point, 0..255, 0 is no correction.
- */
- unsigned int blackLevel;
+ ColorLookupTable red;
+ ColorLookupTable green;
+ ColorLookupTable blue;
};
} /* namespace libcamera */
diff --git a/src/ipa/simple/soft_simple.cpp b/src/ipa/simple/soft_simple.cpp
index 30956a19..c5085f71 100644
--- a/src/ipa/simple/soft_simple.cpp
+++ b/src/ipa/simple/soft_simple.cpp
@@ -5,6 +5,7 @@
* soft_simple.cpp - Simple Software Image Processing Algorithm module
*/
+#include <math.h>
#include <numeric>
#include <stdint.h>
#include <sys/mman.h>
@@ -84,6 +85,10 @@ private:
ControlInfoMap sensorInfoMap_;
BlackLevel blackLevel_;
+ static constexpr unsigned int kGammaLookupSize = 1024;
+ std::array<uint8_t, kGammaLookupSize> gammaTable_;
+ int lastBlackLevel_ = -1;
+
int32_t exposureMin_, exposureMax_;
int32_t exposure_;
double againMin_, againMax_, againMinStep_;
@@ -246,40 +251,59 @@ void IPASoftSimple::processStats(const ControlList &sensorControls)
if (ignoreUpdates_ > 0)
blackLevel_.update(histogram);
const uint8_t blackLevel = blackLevel_.get();
- params_->blackLevel = blackLevel;
/*
* Calculate red and blue gains for AWB.
* Clamp max gain at 4.0, this also avoids 0 division.
*/
- {
- const uint64_t nPixels = std::accumulate(
- histogram.begin(), histogram.end(), 0);
- auto subtractBlackLevel = [blackLevel, nPixels](
- uint64_t sum, uint64_t div)
- -> uint64_t {
- uint64_t reducedSum = sum - blackLevel * nPixels / div;
- uint64_t spreadSum = reducedSum * 256 / (256 - blackLevel);
- return spreadSum;
- };
- const uint64_t sumR = subtractBlackLevel(stats_->sumR_, 4);
- const uint64_t sumG = subtractBlackLevel(stats_->sumG_, 2);
- const uint64_t sumB = subtractBlackLevel(stats_->sumB_, 4);
-
- if (sumR <= sumG / 4)
- params_->gainR = 1024;
- else
- params_->gainR = 256 * sumG / sumR;
-
- if (sumB <= sumG / 4)
- params_->gainB = 1024;
- else
- params_->gainB = 256 * sumG / sumB;
+ const uint64_t nPixels = std::accumulate(
+ histogram.begin(), histogram.end(), 0);
+ auto subtractBlackLevel = [blackLevel, nPixels](
+ uint64_t sum, uint64_t div)
+ -> uint64_t {
+ const uint64_t reducedSum = sum - blackLevel * nPixels / div;
+ const uint64_t spreadSum = reducedSum * 256 / (256 - blackLevel);
+ return spreadSum;
+ };
+ const uint64_t sumR = subtractBlackLevel(stats_->sumR_, 4);
+ const uint64_t sumG = subtractBlackLevel(stats_->sumG_, 2);
+ const uint64_t sumB = subtractBlackLevel(stats_->sumB_, 4);
+
+ /* Gain: 128 = 0.5, 256 = 1.0, 512 = 2.0, etc. */
+ unsigned int gainR = sumR <= sumG / 4 ? 1024 : 256 * sumG / sumR;
+ unsigned int gainB = sumB <= sumG / 4 ? 1024 : 256 * sumG / sumB;
+ /* Green gain and gamma values are fixed */
+ constexpr unsigned int gainG = 256;
+ /* gamma == 1.0 means no correction */
+ constexpr float gamma = 0.5;
+
+ /* Update the gamma table if needed */
+ if (blackLevel != lastBlackLevel_) {
+ const unsigned int blackIndex = blackLevel * kGammaLookupSize / 256;
+ std::fill(gammaTable_.begin(), gammaTable_.begin() + blackIndex, 0);
+ const float divisor = kGammaLookupSize - blackIndex - 1.0;
+ for (unsigned int i = blackIndex; i < kGammaLookupSize; i++)
+ gammaTable_[i] = UINT8_MAX * powf((i - blackIndex) / divisor, gamma);
+
+ lastBlackLevel_ = blackLevel;
}
- /* Green gain and gamma values are fixed */
- params_->gainG = 256;
- params_->gamma = 0.5;
+ for (unsigned int i = 0; i < DebayerParams::kRGBLookupSize; i++) {
+ constexpr unsigned int div =
+ DebayerParams::kRGBLookupSize * DebayerParams::kGain10 /
+ kGammaLookupSize;
+ unsigned int idx;
+
+ /* Apply gamma after gain! */
+ idx = std::min({ i * gainR / div, (kGammaLookupSize - 1) });
+ params_->red[i] = gammaTable_[idx];
+
+ idx = std::min({ i * gainG / div, (kGammaLookupSize - 1) });
+ params_->green[i] = gammaTable_[idx];
+
+ idx = std::min({ i * gainB / div, (kGammaLookupSize - 1) });
+ params_->blue[i] = gammaTable_[idx];
+ }
setIspParams.emit();
@@ -300,7 +324,7 @@ void IPASoftSimple::processStats(const ControlList &sensorControls)
* https://www.araa.asn.au/acra/acra2007/papers/paper84final.pdf
*/
const unsigned int blackLevelHistIdx =
- params_->blackLevel / (256 / SwIspStats::kYHistogramSize);
+ blackLevel / (256 / SwIspStats::kYHistogramSize);
const unsigned int histogramSize =
SwIspStats::kYHistogramSize - blackLevelHistIdx;
const unsigned int yHistValsPerBin = histogramSize / kExposureBinsCount;
@@ -348,8 +372,8 @@ void IPASoftSimple::processStats(const ControlList &sensorControls)
LOG(IPASoft, Debug) << "exposureMSV " << exposureMSV
<< " exp " << exposure_ << " again " << again_
- << " gain R/B " << params_->gainR << "/" << params_->gainB
- << " black level " << params_->blackLevel;
+ << " gain R/B " << gainR << "/" << gainB
+ << " black level " << blackLevel;
}
void IPASoftSimple::updateExposure(double exposureMSV)
diff --git a/src/libcamera/software_isp/debayer.cpp b/src/libcamera/software_isp/debayer.cpp
index 1c035e9b..ac438a33 100644
--- a/src/libcamera/software_isp/debayer.cpp
+++ b/src/libcamera/software_isp/debayer.cpp
@@ -1,7 +1,7 @@
/* SPDX-License-Identifier: LGPL-2.1-or-later */
/*
* Copyright (C) 2023, Linaro Ltd
- * Copyright (C) 2023, Red Hat Inc.
+ * Copyright (C) 2023, 2024 Red Hat Inc.
*
* Authors:
* Hans de Goede <hdegoede at redhat.com>
@@ -24,29 +24,28 @@ namespace libcamera {
*/
/**
- * \var DebayerParams::gainR
- * \brief Red gain
- *
- * 128 = 0.5, 256 = 1.0, 512 = 2.0, etc.
+ * \var DebayerParams::kRGBLookupSize
+ * \brief Size of a color lookup table
*/
/**
- * \var DebayerParams::gainG
- * \brief Green gain
- *
- * 128 = 0.5, 256 = 1.0, 512 = 2.0, etc.
+ * \typedef DebayerParams::ColorLookupTable
+ * \brief Type of the lookup tables for red, green, blue values
*/
/**
- * \var DebayerParams::gainB
- * \brief Blue gain
- *
- * 128 = 0.5, 256 = 1.0, 512 = 2.0, etc.
+ * \var DebayerParams::red
+ * \brief Lookup table for red color, mapping input values to output values
+ */
+
+/**
+ * \var DebayerParams::green
+ * \brief Lookup table for green color, mapping input values to output values
*/
/**
- * \var DebayerParams::gamma
- * \brief Gamma correction, 1.0 is no correction
+ * \var DebayerParams::blue
+ * \brief Lookup table for blue color, mapping input values to output values
*/
/**
diff --git a/src/libcamera/software_isp/debayer_cpu.cpp b/src/libcamera/software_isp/debayer_cpu.cpp
index 88d6578b..8b2b2f40 100644
--- a/src/libcamera/software_isp/debayer_cpu.cpp
+++ b/src/libcamera/software_isp/debayer_cpu.cpp
@@ -11,7 +11,6 @@
#include "debayer_cpu.h"
-#include <math.h>
#include <stdlib.h>
#include <time.h>
@@ -47,9 +46,9 @@ DebayerCpu::DebayerCpu(std::unique_ptr<SwStatsCpu> stats)
*/
enableInputMemcpy_ = true;
- /* Initialize gamma to 1.0 curve */
- for (unsigned int i = 0; i < kGammaLookupSize; i++)
- gamma_[i] = i / (kGammaLookupSize / kRGBLookupSize);
+ /* Initialize color lookup tables */
+ for (unsigned int i = 0; i < DebayerParams::kRGBLookupSize; i++)
+ red_[i] = green_[i] = blue_[i] = i;
for (unsigned int i = 0; i < kMaxLineBuffers; i++)
lineBuffers_[i] = nullptr;
@@ -698,37 +697,9 @@ void DebayerCpu::process(FrameBuffer *input, FrameBuffer *output, DebayerParams
clock_gettime(CLOCK_MONOTONIC_RAW, &frameStartTime);
}
- /* Apply DebayerParams */
- if (params.gamma != gammaCorrection_ || params.blackLevel != blackLevel_) {
- const unsigned int blackIndex =
- params.blackLevel * kGammaLookupSize / 256;
- std::fill(gamma_.begin(), gamma_.begin() + blackIndex, 0);
- const float divisor = kGammaLookupSize - blackIndex - 1.0;
- for (unsigned int i = blackIndex; i < kGammaLookupSize; i++)
- gamma_[i] = UINT8_MAX * powf((i - blackIndex) / divisor, params.gamma);
-
- gammaCorrection_ = params.gamma;
- blackLevel_ = params.blackLevel;
- }
-
- if (swapRedBlueGains_)
- std::swap(params.gainR, params.gainB);
-
- for (unsigned int i = 0; i < kRGBLookupSize; i++) {
- constexpr unsigned int div =
- kRGBLookupSize * DebayerParams::kGain10 / kGammaLookupSize;
- unsigned int idx;
-
- /* Apply gamma after gain! */
- idx = std::min({ i * params.gainR / div, (kGammaLookupSize - 1) });
- red_[i] = gamma_[idx];
-
- idx = std::min({ i * params.gainG / div, (kGammaLookupSize - 1) });
- green_[i] = gamma_[idx];
-
- idx = std::min({ i * params.gainB / div, (kGammaLookupSize - 1) });
- blue_[i] = gamma_[idx];
- }
+ green_ = params.green;
+ red_ = swapRedBlueGains_ ? params.blue : params.red;
+ blue_ = swapRedBlueGains_ ? params.red : params.blue;
/* Copy metadata from the input buffer */
FrameMetadata &metadata = output->_d()->metadata();
diff --git a/src/libcamera/software_isp/debayer_cpu.h b/src/libcamera/software_isp/debayer_cpu.h
index 689c1075..47373426 100644
--- a/src/libcamera/software_isp/debayer_cpu.h
+++ b/src/libcamera/software_isp/debayer_cpu.h
@@ -122,15 +122,12 @@ private:
void process2(const uint8_t *src, uint8_t *dst);
void process4(const uint8_t *src, uint8_t *dst);
- static constexpr unsigned int kGammaLookupSize = 1024;
- static constexpr unsigned int kRGBLookupSize = 256;
/* Max. supported Bayer pattern height is 4, debayering this requires 5 lines */
static constexpr unsigned int kMaxLineBuffers = 5;
- std::array<uint8_t, kGammaLookupSize> gamma_;
- std::array<uint8_t, kRGBLookupSize> red_;
- std::array<uint8_t, kRGBLookupSize> green_;
- std::array<uint8_t, kRGBLookupSize> blue_;
+ DebayerParams::ColorLookupTable red_;
+ DebayerParams::ColorLookupTable green_;
+ DebayerParams::ColorLookupTable blue_;
debayerFn debayer0_;
debayerFn debayer1_;
debayerFn debayer2_;
diff --git a/src/libcamera/software_isp/software_isp.cpp b/src/libcamera/software_isp/software_isp.cpp
index e4e56086..3e07453d 100644
--- a/src/libcamera/software_isp/software_isp.cpp
+++ b/src/libcamera/software_isp/software_isp.cpp
@@ -63,9 +63,7 @@ LOG_DEFINE_CATEGORY(SoftwareIsp)
* handler
*/
SoftwareIsp::SoftwareIsp(PipelineHandler *pipe, const CameraSensor *sensor)
- : debayerParams_{ DebayerParams::kGain10, DebayerParams::kGain10,
- DebayerParams::kGain10, 0.5f, 0 },
- dmaHeap_(DmaHeap::DmaHeapFlag::Cma | DmaHeap::DmaHeapFlag::System)
+ : dmaHeap_(DmaHeap::DmaHeapFlag::Cma | DmaHeap::DmaHeapFlag::System)
{
if (!dmaHeap_.isValid()) {
LOG(SoftwareIsp, Error) << "Failed to create DmaHeap object";
--
2.42.0
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