From patchwork Fri Jul 31 21:10:40 2026 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Milan Zamazal X-Patchwork-Id: 27535 Return-Path: X-Original-To: parsemail@patchwork.libcamera.org Delivered-To: parsemail@patchwork.libcamera.org Received: from lancelot.ideasonboard.com (lancelot.ideasonboard.com [92.243.16.209]) by patchwork.libcamera.org (Postfix) with ESMTPS id 8FA2BBDE4C for ; Fri, 31 Jul 2026 21:11:14 +0000 (UTC) Received: from lancelot.ideasonboard.com (localhost [IPv6:::1]) by lancelot.ideasonboard.com (Postfix) with ESMTP id 57BC867FE8; Fri, 31 Jul 2026 23:11:14 +0200 (CEST) Authentication-Results: lancelot.ideasonboard.com; dkim=pass (1024-bit key; unprotected) header.d=redhat.com header.i=@redhat.com header.b="Pf6POwK7"; dkim-atps=neutral Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lancelot.ideasonboard.com (Postfix) with ESMTPS id CA4C465F9F for ; Fri, 31 Jul 2026 23:11:12 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1785532271; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=oLvxlfLFiPFKN2HKLVuoZCKUn58qcf5Zo1Yx+J1QdVc=; b=Pf6POwK7oue5P4BVByoCCfyjHHuQuI+E/hiKHYwmb1UGDL7q/6Hr2DIoZPmp0ZXxaJjtrG eqSMbbBb7+/W+90/gNvoI/9KRH/oM40ZAUEjp/+PnO7lRT15qgC1h+6CBchMomniEHxAo0 lugVbMXQTyiIjxWPEx1Je1+6yZzKWjw= Received: from mx-prod-mc-08.mail-002.prod.us-west-2.aws.redhat.com (ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-228-L-Cz3m9uOJCb7dVwOB4Byw-1; Fri, 31 Jul 2026 17:11:08 -0400 X-MC-Unique: L-Cz3m9uOJCb7dVwOB4Byw-1 X-Mimecast-MFC-AGG-ID: L-Cz3m9uOJCb7dVwOB4Byw_1785532266 Received: from mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.93]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 70CA11800348; Fri, 31 Jul 2026 21:11:06 +0000 (UTC) Received: from mzamazal-thinkpadp1gen7.tpbc.com (unknown [10.44.32.42]) by mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 2721D180056E; Fri, 31 Jul 2026 21:11:02 +0000 (UTC) From: Milan Zamazal To: libcamera-devel@lists.libcamera.org Cc: Xander Pronk , Bryan O'Donoghue , Hans de Goede , Laurent Pinchart , Robert Mader , Rick ten Wolde , Milan Zamazal Subject: [RFC PATCH v10 3/6] ipa: simple: Add LSC algorithm Date: Fri, 31 Jul 2026 23:10:40 +0200 Message-ID: <20260731211044.135970-4-mzamazal@redhat.com> In-Reply-To: <20260731211044.135970-1-mzamazal@redhat.com> References: <20260731211044.135970-1-mzamazal@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.93 X-Mimecast-Spam-Score: 0 X-Mimecast-MFC-PROC-ID: F2T_inbyoqbX8JWAH3Mn7_DYognrNBG8-bChz9EtZG4_1785532266 X-Mimecast-Originator: redhat.com content-type: text/plain; charset="US-ASCII"; x-default=true X-BeenThere: libcamera-devel@lists.libcamera.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: libcamera-devel-bounces@lists.libcamera.org Sender: "libcamera-devel" From: Xander Pronk The algorithm is based on the common libipa lens shading correction implementation. The grid values obtained from the libipa algorithm are passed to the debayer algorithm as an array and used as an an RGB texture. Notes on the implementation: - The overall idea is to keep things simple, to not make the LSC computation unnecessarily expensive. - LscAlgorithm accepts only quantised types. UQ<2,6> is used, to be converted to float in debayering. - The limit of 100 degrees to consider a temperature change noticeable is arbitrary. Co-developed-by: Rick ten Wolde Signed-off-by: Rick ten Wolde Signed-off-by: Xander Pronk Signed-off-by: Milan Zamazal --- src/ipa/simple/algorithms/lsc.cpp | 99 +++++++++++++++++++++++++++ src/ipa/simple/algorithms/lsc.h | 82 ++++++++++++++++++++++ src/ipa/simple/algorithms/meson.build | 1 + src/ipa/simple/ipa_context.h | 5 ++ 4 files changed, 187 insertions(+) create mode 100644 src/ipa/simple/algorithms/lsc.cpp create mode 100644 src/ipa/simple/algorithms/lsc.h diff --git a/src/ipa/simple/algorithms/lsc.cpp b/src/ipa/simple/algorithms/lsc.cpp new file mode 100644 index 000000000..618d2135c --- /dev/null +++ b/src/ipa/simple/algorithms/lsc.cpp @@ -0,0 +1,99 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ +/* + * Lens shading correction + */ + +#include "lsc.h" + +#include + +namespace libcamera { + +namespace ipa::soft::algorithms { + +LOG_DEFINE_CATEGORY(IPASoftLsc) + +int Lsc::init(IPAContext &context, const ValueNode &tuningData) +{ + static constexpr unsigned int kGridSize = DebayerParams::kLscGridSize; + + for (unsigned int i = 0; i < kGridSize; i++) + gridPos_.push_back(static_cast(i) / (kGridSize - 1)); + + return lscAlgo_.init(tuningData, context.ctrlMap, + { .keys = { "r", "g", "b" }, + .numHSamples = kGridSize, + .numVSamples = kGridSize, + .sensorSize = context.sensorInfo.activeAreaSize }); +} + +int Lsc::configure(IPAContext &context, + [[maybe_unused]] const IPAConfigInfo &configInfo) +{ + return lscAlgo_.configure(context.activeState.lsc, + context.sensorInfo.analogCrop, + gridPos_, gridPos_); +} + +void Lsc::prepare([[maybe_unused]] IPAContext &context, + [[maybe_unused]] const uint32_t frame, + IPAFrameContext &frameContext, + DebayerParams *params) +{ + unsigned int ct = frameContext.awb.colourTemperature; + constexpr unsigned int minTemperatureChange = 100; + + if (!frameContext.lsc.enabled) { + if (lastAppliedCt_ != 0 || params->lscLutVersion == 0) { + params->lscLut.fill(64); /* UQ<2, 6>(64) == 1.0 */ + params->lscLutVersion++; + lastAppliedCt_ = 0; + } + return; + } + + if (utils::abs_diff(ct, lastAppliedCt_) < minTemperatureChange) + return; + + const SimpleLscAlgorithm::Components &set = + lscAlgo_.getInterpolator().getInterpolated(ct); + + const auto &red = set.at("r"); + const auto &green = set.at("g"); + const auto &blue = set.at("b"); + + DebayerParams::LscLookupTable lut; + constexpr unsigned int gridSize = DebayerParams::kLscGridSize; + for (unsigned int i = 0, j = 0; i < gridSize * gridSize; i++) { + lut[j++] = red[i]; + lut[j++] = green[i]; + lut[j++] = blue[i]; + lut[j++] = 0; /* padding */ + } + params->lscLut = lut; + params->lscLutVersion++; + + lastAppliedCt_ = ct; +} + +void Lsc::queueRequest(IPAContext &context, [[maybe_unused]] const uint32_t frame, + IPAFrameContext &frameContext, const ControlList &controls) +{ + lscAlgo_.queueRequest(context.activeState.lsc, frameContext.lsc, + controls); +} + +void Lsc::process([[maybe_unused]] IPAContext &context, + [[maybe_unused]] const uint32_t frame, + IPAFrameContext &frameContext, + [[maybe_unused]] const SwIspStats *stats, + ControlList &metadata) +{ + lscAlgo_.process(frameContext.lsc, metadata); +} + +REGISTER_IPA_ALGORITHM(Lsc, "Lsc") + +} /* namespace ipa::soft::algorithms */ + +} /* namespace libcamera */ diff --git a/src/ipa/simple/algorithms/lsc.h b/src/ipa/simple/algorithms/lsc.h new file mode 100644 index 000000000..981aaef53 --- /dev/null +++ b/src/ipa/simple/algorithms/lsc.h @@ -0,0 +1,82 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ +/* + * Lens shading correction + */ + +#pragma once + +#include + +#include "libipa/fixedpoint.h" +#include "libipa/lsc.h" + +#include "algorithm.h" +#include "ipa_context.h" + +namespace libcamera { + +namespace ipa { + +namespace soft::algorithms { + +using SimpleLscAlgorithm = LscAlgorithm>; +using SimpleComponents = SimpleLscAlgorithm::Components; +using SimpleComponentsMap = SimpleLscAlgorithm::ComponentsMap; + +class Lsc : public Algorithm +{ +public: + Lsc() = default; + ~Lsc() = default; + + int init(IPAContext &context, const ValueNode &tuningData) override; + int configure(IPAContext &context, + const IPAConfigInfo &configInfo) override; + void queueRequest(IPAContext &context, [[maybe_unused]] const uint32_t frame, + IPAFrameContext &frameContext, const ControlList &controls) override; + void prepare(IPAContext &context, + const uint32_t frame, + IPAFrameContext &frameContext, + DebayerParams *params) override; + void process([[maybe_unused]] IPAContext &context, + [[maybe_unused]] const uint32_t frame, + IPAFrameContext &frameContext, + [[maybe_unused]] const SwIspStats *stats, + ControlList &metadata) override; + +private: + SimpleLscAlgorithm lscAlgo_; + std::vector gridPos_; + + unsigned int lastAppliedCt_ = 0; +}; + +} /* namespace soft::algorithms */ + +#ifndef __DOXYGEN__ +template +void interpolateVector(const std::vector &a, + const std::vector &b, + std::vector &dest, double lambda) +{ + ASSERT(a.size() == b.size()); + dest.resize(a.size()); + for (size_t i = 0; i < a.size(); i++) + dest[i] = a[i] * (1.0 - lambda) + b[i] * lambda; +} + +template<> +void Interpolator:: + interpolate(const soft::algorithms::SimpleComponents &a, + const soft::algorithms::SimpleComponents &b, + soft::algorithms::SimpleComponents &dest, + double lambda) +{ + for (auto const &[k, v] : a) + interpolateVector(v, b.at(k), dest[k], lambda); +} +#endif /* __DOXYGEN__ */ + +} /* namespace ipa */ + +} /* namespace libcamera */ diff --git a/src/ipa/simple/algorithms/meson.build b/src/ipa/simple/algorithms/meson.build index 73c637220..c9f6e5590 100644 --- a/src/ipa/simple/algorithms/meson.build +++ b/src/ipa/simple/algorithms/meson.build @@ -6,4 +6,5 @@ soft_simple_ipa_algorithms = files([ 'agc.cpp', 'blc.cpp', 'ccm.cpp', + 'lsc.cpp', ]) diff --git a/src/ipa/simple/ipa_context.h b/src/ipa/simple/ipa_context.h index ff312ae8f..23c2cfd0a 100644 --- a/src/ipa/simple/ipa_context.h +++ b/src/ipa/simple/ipa_context.h @@ -19,6 +19,7 @@ #include #include #include +#include "libipa/lsc.h" #include "core_ipa_interface.h" @@ -61,6 +62,8 @@ struct IPAActiveState { std::optional contrast; std::optional saturation; } knobs; + + ipa::lsc::ActiveState lsc; }; struct IPAFrameContext : public FrameContext { @@ -75,6 +78,7 @@ struct IPAFrameContext : public FrameContext { float gamma; std::optional contrast; std::optional saturation; + ipa::lsc::FrameContext lsc; }; struct IPAContext { @@ -89,6 +93,7 @@ struct IPAContext { FCQueue frameContexts; ControlInfoMap::Map ctrlMap; bool ccmEnabled = false; + ipa::lsc::ActiveState lsc; }; } /* namespace ipa::soft */