[PATCH 15/19] libcamera: software_isp: Move color handling to an algorithm module
Milan Zamazal
mzamazal at redhat.com
Wed Jun 26 09:20:56 CEST 2024
After black level handling has been moved to an algorithm module, white
balance and the construction of color tables can be moved to an
algorithm module too. This time, the moved code is split between stats
processing and parameter construction methods.
This is the only part of the software ISP algorithms that sets the
parameters so emitting setIspParams can be moved to prepare() method.
A more natural representation of the gains (and black level) would be
floating point numbers. This is not done here in order to minimize
changes in code movements. It will be addressed in a followup patch.
Signed-off-by: Milan Zamazal <mzamazal at redhat.com>
---
src/ipa/simple/algorithms/colors.cpp | 119 ++++++++++++++++++++++++++
src/ipa/simple/algorithms/colors.h | 46 ++++++++++
src/ipa/simple/algorithms/meson.build | 1 +
src/ipa/simple/data/uncalibrated.yaml | 1 +
src/ipa/simple/ipa_context.h | 9 ++
src/ipa/simple/soft_simple.cpp | 66 +-------------
6 files changed, 180 insertions(+), 62 deletions(-)
create mode 100644 src/ipa/simple/algorithms/colors.cpp
create mode 100644 src/ipa/simple/algorithms/colors.h
diff --git a/src/ipa/simple/algorithms/colors.cpp b/src/ipa/simple/algorithms/colors.cpp
new file mode 100644
index 00000000..d4ab409c
--- /dev/null
+++ b/src/ipa/simple/algorithms/colors.cpp
@@ -0,0 +1,119 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2024, Red Hat Inc.
+ *
+ * Color gains (AWB + gamma)
+ */
+
+#include "colors.h"
+
+#include <algorithm>
+#include <cmath>
+#include <numeric>
+#include <stdint.h>
+
+#include <libcamera/base/log.h>
+
+#include "simple/ipa_context.h"
+
+namespace libcamera {
+
+LOG_DEFINE_CATEGORY(IPASoftColors)
+
+namespace ipa::soft::algorithms {
+
+static constexpr unsigned int kGammaLookupSize = 1024;
+
+Colors::Colors()
+{
+}
+
+int Colors::init(IPAContext &context,
+ [[maybe_unused]] const YamlObject &tuningData)
+{
+ /* Gamma value is fixed */
+ context.configuration.gamma = 0.5;
+ updateGammaTable(context);
+
+ auto &gains = context.activeState.gains;
+ gains.red = gains.green = gains.blue = 256;
+
+ return 0;
+}
+
+void Colors::updateGammaTable(IPAContext &context)
+{
+ auto &gammaTable = context.activeState.gammaTable;
+ const unsigned int blackIndex =
+ context.configuration.black.level * IPAActiveState::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,
+ context.configuration.gamma);
+}
+
+void Colors::prepare(IPAContext &context,
+ [[maybe_unused]] const uint32_t frame,
+ [[maybe_unused]] IPAFrameContext &frameContext,
+ DebayerParams *params)
+{
+ /* Update the gamma table if needed */
+ if (context.configuration.black.changed)
+ updateGammaTable(context);
+
+ auto &gains = context.activeState.gains;
+ auto &gammaTable = context.activeState.gammaTable;
+ for (unsigned int i = 0; i < DebayerParams::kRGBLookupSize; i++) {
+ constexpr unsigned int div =
+ static_cast<double>(DebayerParams::kRGBLookupSize) * 256 / kGammaLookupSize;
+ /* Apply gamma after gain! */
+ unsigned int idx;
+ idx = std::min({ i * gains.red / div, kGammaLookupSize - 1 });
+ params->red[i] = gammaTable[idx];
+ idx = std::min({ i * gains.green / div, kGammaLookupSize - 1 });
+ params->green[i] = gammaTable[idx];
+ idx = std::min({ i * gains.blue / div, kGammaLookupSize - 1 });
+ params->blue[i] = gammaTable[idx];
+ }
+}
+
+void Colors::process(IPAContext &context,
+ [[maybe_unused]] const uint32_t frame,
+ [[maybe_unused]] IPAFrameContext &frameContext,
+ const SwIspStats *stats,
+ [[maybe_unused]] ControlList &metadata)
+{
+ const SwIspStats::Histogram &histogram = stats->yHistogram;
+ const uint8_t blackLevel = context.configuration.black.level;
+
+ /*
+ * Black level must be subtracted to get the correct AWB ratios, they
+ * would be off if they were computed from the whole brightness range
+ * rather than from the sensor range.
+ */
+ const uint64_t nPixels = std::accumulate(
+ histogram.begin(), histogram.end(), 0);
+ const uint64_t offset = blackLevel * nPixels;
+ const uint64_t sumR = stats->sumR_ - offset / 4;
+ const uint64_t sumG = stats->sumG_ - offset / 2;
+ const uint64_t sumB = stats->sumB_ - offset / 4;
+
+ /*
+ * Calculate red and blue gains for AWB.
+ * Clamp max gain at 4.0, this also avoids 0 division.
+ * Gain: 128 = 0.5, 256 = 1.0, 512 = 2.0, etc.
+ */
+ auto &gains = context.activeState.gains;
+ gains.red = sumR <= sumG / 4 ? 1024 : 256 * sumG / sumR;
+ gains.blue = sumB <= sumG / 4 ? 1024 : 256 * sumG / sumB;
+ /* Green gain is fixed to 256 */
+
+ LOG(IPASoftColors, Debug) << "gain R/B " << gains.red << "/" << gains.blue;
+}
+
+REGISTER_IPA_ALGORITHM(Colors, "Colors")
+
+} /* namespace ipa::soft::algorithms */
+
+} /* namespace libcamera */
diff --git a/src/ipa/simple/algorithms/colors.h b/src/ipa/simple/algorithms/colors.h
new file mode 100644
index 00000000..2c2f7752
--- /dev/null
+++ b/src/ipa/simple/algorithms/colors.h
@@ -0,0 +1,46 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2024, Red Hat Inc.
+ *
+ * Color gains (AWB + gamma)
+ */
+
+#pragma once
+
+#include <libcamera/controls.h>
+
+#include "libcamera/internal/software_isp/debayer_params.h"
+#include "libcamera/internal/software_isp/swisp_stats.h"
+
+#include "algorithm.h"
+#include "ipa_context.h"
+
+namespace libcamera {
+
+namespace ipa::soft::algorithms {
+
+class Colors : public Algorithm
+{
+public:
+ Colors();
+ ~Colors() = default;
+
+ int init(IPAContext &context, const YamlObject &tuningData)
+ override;
+ void prepare(IPAContext &context,
+ const uint32_t frame,
+ IPAFrameContext &frameContext,
+ DebayerParams *params) override;
+ void process(IPAContext &context,
+ const uint32_t frame,
+ IPAFrameContext &frameContext,
+ const SwIspStats *stats,
+ ControlList &metadata) override;
+
+private:
+ void updateGammaTable(IPAContext &context);
+};
+
+} /* namespace ipa::soft::algorithms */
+
+} /* namespace libcamera */
diff --git a/src/ipa/simple/algorithms/meson.build b/src/ipa/simple/algorithms/meson.build
index 1f63c220..324c7b4e 100644
--- a/src/ipa/simple/algorithms/meson.build
+++ b/src/ipa/simple/algorithms/meson.build
@@ -2,4 +2,5 @@
soft_simple_ipa_algorithms = files([
'blc.cpp',
+ 'colors.cpp',
])
diff --git a/src/ipa/simple/data/uncalibrated.yaml b/src/ipa/simple/data/uncalibrated.yaml
index e0d03d96..7e5149e5 100644
--- a/src/ipa/simple/data/uncalibrated.yaml
+++ b/src/ipa/simple/data/uncalibrated.yaml
@@ -4,4 +4,5 @@
version: 1
algorithms:
- BlackLevel:
+ - Colors:
...
diff --git a/src/ipa/simple/ipa_context.h b/src/ipa/simple/ipa_context.h
index c79bf6f8..991a45b1 100644
--- a/src/ipa/simple/ipa_context.h
+++ b/src/ipa/simple/ipa_context.h
@@ -8,6 +8,7 @@
#pragma once
+#include <array>
#include <stdint.h>
#include <libipa/fc_queue.h>
@@ -17,6 +18,7 @@ namespace libcamera {
namespace ipa::soft {
struct IPASessionConfiguration {
+ float gamma;
struct {
uint8_t level;
bool set;
@@ -25,6 +27,13 @@ struct IPASessionConfiguration {
};
struct IPAActiveState {
+ struct {
+ unsigned int red;
+ unsigned int green;
+ unsigned int blue;
+ } gains;
+ static constexpr unsigned int kGammaLookupSize = 1024;
+ std::array<double, kGammaLookupSize> gammaTable;
};
struct IPAFrameContext : public FrameContext {
diff --git a/src/ipa/simple/soft_simple.cpp b/src/ipa/simple/soft_simple.cpp
index 99fb953c..25f6a71e 100644
--- a/src/ipa/simple/soft_simple.cpp
+++ b/src/ipa/simple/soft_simple.cpp
@@ -5,8 +5,6 @@
* Simple Software Image Processing Algorithm module
*/
-#include <cmath>
-#include <numeric>
#include <stdint.h>
#include <sys/mman.h>
@@ -93,9 +91,6 @@ private:
std::unique_ptr<CameraSensorHelper> camHelper_;
ControlInfoMap sensorInfoMap_;
- static constexpr unsigned int kGammaLookupSize = 1024;
- std::array<uint8_t, kGammaLookupSize> gammaTable_;
- int lastBlackLevel_ = -1;
/* Local parameter storage */
struct IPAContext context_;
@@ -275,6 +270,7 @@ void IPASoftSimple::prepare(const uint32_t frame)
IPAFrameContext &frameContext = context_.frameContexts.get(frame);
for (auto const &algo : algorithms())
algo->prepare(context_, frame, frameContext, params_);
+ setIspParams.emit();
}
void IPASoftSimple::queueRequest(const uint32_t frame, const ControlList &controls)
@@ -302,62 +298,6 @@ void IPASoftSimple::processStats(
algo->process(context_, frame, frameContext, stats_, metadata);
}
- SwIspStats::Histogram histogram = stats_->yHistogram;
- const uint8_t blackLevel = context_.configuration.black.level;
-
- /*
- * Black level must be subtracted to get the correct AWB ratios, they
- * would be off if they were computed from the whole brightness range
- * rather than from the sensor range.
- */
- const uint64_t nPixels = std::accumulate(
- histogram.begin(), histogram.end(), 0);
- const uint64_t offset = blackLevel * nPixels;
- const uint64_t sumR = stats_->sumR_ - offset / 4;
- const uint64_t sumG = stats_->sumG_ - offset / 2;
- const uint64_t sumB = stats_->sumB_ - offset / 4;
-
- /*
- * Calculate red and blue gains for AWB.
- * Clamp max gain at 4.0, this also avoids 0 division.
- * Gain: 128 = 0.5, 256 = 1.0, 512 = 2.0, etc.
- */
- const unsigned int gainR = sumR <= sumG / 4 ? 1024 : 256 * sumG / sumR;
- const unsigned int gainB = sumB <= sumG / 4 ? 1024 : 256 * sumG / sumB;
- /* Green gain and gamma values are fixed */
- constexpr unsigned int gainG = 256;
-
- /* Update the gamma table if needed */
- if (blackLevel != lastBlackLevel_) {
- constexpr float gamma = 0.5;
- 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 *
- std::pow((i - blackIndex) / divisor, gamma);
-
- lastBlackLevel_ = blackLevel;
- }
-
- for (unsigned int i = 0; i < DebayerParams::kRGBLookupSize; i++) {
- constexpr unsigned int div =
- DebayerParams::kRGBLookupSize * 256 / 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();
-
/* \todo Switch to the libipa/algorithm.h API someday. */
/*
@@ -374,6 +314,7 @@ void IPASoftSimple::processStats(
* Calculate Mean Sample Value (MSV) according to formula from:
* https://www.araa.asn.au/acra/acra2007/papers/paper84final.pdf
*/
+ const uint8_t blackLevel = context_.configuration.black.level;
const unsigned int blackLevelHistIdx =
blackLevel / (256 / SwIspStats::kYHistogramSize);
const unsigned int histogramSize =
@@ -423,7 +364,8 @@ void IPASoftSimple::processStats(
LOG(IPASoft, Debug) << "exposureMSV " << exposureMSV
<< " exp " << exposure_ << " again " << again_
- << " gain R/B " << gainR << "/" << gainB
+ << " gain R/B " << context_.activeState.gains.red
+ << "/" << context_.activeState.gains.blue
<< " black level " << static_cast<unsigned int>(blackLevel);
}
--
2.44.1
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