From 59ac34b728c573317fd37ad10e6d1c9df486c5e4 Mon Sep 17 00:00:00 2001 From: Milan Zamazal Date: Thu, 15 May 2025 18:04:31 +0200 Subject: [PATCH] libcamera: software_isp: Add saturation control Saturation control is added on top of the colour correction matrix. A method of saturation adjustment that can be fully integrated into the colour correction matrix is used. The control is available only if Ccm algorithm is enabled. The control uses 0.0-2.0 value range, with 1.0 being unmodified saturation, 0.0 full desaturation and 2.0 quite saturated. The saturation is adjusted by converting to Y'CbCr colour space, applying the saturation value on the colour axes, and converting back to RGB. ITU-R BT.601 conversion is used to convert between the colour spaces, for no particular reason. The colour correction matrix is applied before gamma and the given matrix is suitable for such a case. Alternatively, the transformation used in libcamera rpi ccm.cpp could be used. Signed-off-by: Milan Zamazal Reviewed-by: Paul Elder Reviewed-by: Kieran Bingham Signed-off-by: Kieran Bingham --- src/ipa/simple/algorithms/ccm.cpp | 60 +++++++++++++++++++++++++++++-- src/ipa/simple/algorithms/ccm.h | 11 ++++++ src/ipa/simple/ipa_context.h | 4 +++ 3 files changed, 72 insertions(+), 3 deletions(-) diff --git a/src/ipa/simple/algorithms/ccm.cpp b/src/ipa/simple/algorithms/ccm.cpp index d5ba928d3..0a98406c1 100644 --- a/src/ipa/simple/algorithms/ccm.cpp +++ b/src/ipa/simple/algorithms/ccm.cpp @@ -3,7 +3,7 @@ * Copyright (C) 2024, Ideas On Board * Copyright (C) 2024-2025, Red Hat Inc. * - * Color correction matrix + * Color correction matrix + saturation */ #include "ccm.h" @@ -13,6 +13,8 @@ #include +#include "libcamera/internal/matrix.h" + namespace { constexpr unsigned int kTemperatureThreshold = 100; @@ -35,28 +37,77 @@ int Ccm::init([[maybe_unused]] IPAContext &context, const YamlObject &tuningData } context.ccmEnabled = true; + context.ctrlMap[&controls::Saturation] = ControlInfo(0.0f, 2.0f, 1.0f); return 0; } +int Ccm::configure(IPAContext &context, + [[maybe_unused]] const IPAConfigInfo &configInfo) +{ + context.activeState.knobs.saturation = std::optional(); + + return 0; +} + +void Ccm::queueRequest(typename Module::Context &context, + [[maybe_unused]] const uint32_t frame, + [[maybe_unused]] typename Module::FrameContext &frameContext, + const ControlList &controls) +{ + const auto &saturation = controls.get(controls::Saturation); + if (saturation.has_value()) { + context.activeState.knobs.saturation = saturation; + LOG(IPASoftCcm, Debug) << "Setting saturation to " << saturation.value(); + } +} + +void Ccm::applySaturation(Matrix &ccm, float saturation) +{ + /* https://en.wikipedia.org/wiki/YCbCr#ITU-R_BT.601_conversion */ + const Matrix rgb2ycbcr{ + { 0.256788235294, 0.504129411765, 0.0979058823529, + -0.148223529412, -0.290992156863, 0.439215686275, + 0.439215686275, -0.367788235294, -0.0714274509804 } + }; + const Matrix ycbcr2rgb{ + { 1.16438356164, 0, 1.59602678571, + 1.16438356164, -0.391762290094, -0.812967647235, + 1.16438356164, 2.01723214285, 0 } + }; + const Matrix saturationMatrix{ + { 1, 0, 0, + 0, saturation, 0, + 0, 0, saturation } + }; + ccm = ycbcr2rgb * saturationMatrix * rgb2ycbcr * ccm; +} + void Ccm::prepare(IPAContext &context, const uint32_t frame, IPAFrameContext &frameContext, [[maybe_unused]] DebayerParams *params) { + auto &saturation = context.activeState.knobs.saturation; + const unsigned int ct = context.activeState.awb.temperatureK; - /* Change CCM only on bigger temperature changes. */ + /* Change CCM only on saturation or bigger temperature changes. */ if (frame > 0 && - utils::abs_diff(ct, lastCt_) < kTemperatureThreshold) { + utils::abs_diff(ct, lastCt_) < kTemperatureThreshold && + saturation == lastSaturation_) { frameContext.ccm.ccm = context.activeState.ccm.ccm; context.activeState.ccm.changed = false; return; } lastCt_ = ct; + lastSaturation_ = saturation; Matrix ccm = ccm_.getInterpolated(ct); + if (saturation) + applySaturation(ccm, saturation.value()); context.activeState.ccm.ccm = ccm; frameContext.ccm.ccm = ccm; + frameContext.saturation = saturation; context.activeState.ccm.changed = true; } @@ -67,6 +118,9 @@ void Ccm::process([[maybe_unused]] IPAContext &context, ControlList &metadata) { metadata.set(controls::ColourCorrectionMatrix, frameContext.ccm.ccm.data()); + + const auto &saturation = frameContext.saturation; + metadata.set(controls::Saturation, saturation.value_or(1.0)); } REGISTER_IPA_ALGORITHM(Ccm, "Ccm") diff --git a/src/ipa/simple/algorithms/ccm.h b/src/ipa/simple/algorithms/ccm.h index f4e2b85b9..8279a3d59 100644 --- a/src/ipa/simple/algorithms/ccm.h +++ b/src/ipa/simple/algorithms/ccm.h @@ -7,6 +7,8 @@ #pragma once +#include + #include "libcamera/internal/matrix.h" #include @@ -24,6 +26,12 @@ public: ~Ccm() = default; int init(IPAContext &context, const YamlObject &tuningData) override; + int configure(IPAContext &context, + const IPAConfigInfo &configInfo) override; + void queueRequest(typename Module::Context &context, + const uint32_t frame, + typename Module::FrameContext &frameContext, + const ControlList &controls) override; void prepare(IPAContext &context, const uint32_t frame, IPAFrameContext &frameContext, @@ -34,7 +42,10 @@ public: ControlList &metadata) override; private: + void applySaturation(Matrix &ccm, float saturation); + unsigned int lastCt_; + std::optional lastSaturation_; Interpolator> ccm_; }; diff --git a/src/ipa/simple/ipa_context.h b/src/ipa/simple/ipa_context.h index 88cc6c353..a471b80ae 100644 --- a/src/ipa/simple/ipa_context.h +++ b/src/ipa/simple/ipa_context.h @@ -63,6 +63,7 @@ struct IPAActiveState { struct { /* 0..2 range, 1.0 = normal */ std::optional contrast; + std::optional saturation; } knobs; }; @@ -75,11 +76,14 @@ struct IPAFrameContext : public FrameContext { int32_t exposure; double gain; } sensor; + struct { double red; double blue; } gains; + std::optional contrast; + std::optional saturation; }; struct IPAContext {