From patchwork Mon Aug 10 19:02:18 2026 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Milan Zamazal X-Patchwork-Id: 27738 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 D21E3BE080 for ; Mon, 10 Aug 2026 19:03:01 +0000 (UTC) Received: from lancelot.ideasonboard.com (localhost [IPv6:::1]) by lancelot.ideasonboard.com (Postfix) with ESMTP id 93F6C68209; Mon, 10 Aug 2026 21:03:01 +0200 (CEST) Authentication-Results: lancelot.ideasonboard.com; dkim=pass (1024-bit key; unprotected) header.d=redhat.com header.i=@redhat.com header.b="PrpL104t"; 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 F2C4568193 for ; Mon, 10 Aug 2026 21:02:59 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1786388579; 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=NONNbd1NdSAfl5EaOCC0+/ZQKVI4QZ/8lpL9jX8ow5w=; b=PrpL104txHqz8ZHA0RuBGcSwexDQ0zjHQC5ieHAUtJDvdKr9WSMlAOIb3npq62S7UMzaUh NGU37gayqDvqrw0ukR38OF9k4R1Ax/FrR2un0oLioJZoCy50YH6UpRwHcBqwrX4OkYR+NX foYy10S7XSTetXX6i8Wxkv9kfGMPsCk= Received: from mx-prod-mc-06.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-550-7UDwF_tSNHqBw6jPu_y-SA-1; Mon, 10 Aug 2026 15:02:50 -0400 X-MC-Unique: 7UDwF_tSNHqBw6jPu_y-SA-1 X-Mimecast-MFC-AGG-ID: 7UDwF_tSNHqBw6jPu_y-SA_1786388569 Received: from mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.4]) (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-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 3497E18004BB; Mon, 10 Aug 2026 19:02:49 +0000 (UTC) Received: from mzamazal-thinkpadp1gen7.tpbc.csb (headnet03.pony-001.prod.iad2.dc.redhat.com [10.2.32.114]) by mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 4BAC13001D3B; Mon, 10 Aug 2026 19:02:45 +0000 (UTC) From: Milan Zamazal To: libcamera-devel@lists.libcamera.org Cc: Xander Pronk , Bryan O'Donoghue , Hans de Goede , Laurent Pinchart , Robert Mader , =?utf-8?q?Barnab=C3=A1s_P=C5=91cze?= , Rick ten Wolde , Milan Zamazal Subject: [PATCH v12 3/7] ipa: simple: Add LSC algorithm Date: Mon, 10 Aug 2026 21:02:18 +0200 Message-ID: <20260810190222.129260-4-mzamazal@redhat.com> In-Reply-To: <20260810190222.129260-1-mzamazal@redhat.com> References: <20260810190222.129260-1-mzamazal@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.4 X-Mimecast-Spam-Score: 0 X-Mimecast-MFC-PROC-ID: -qZsihrlA7IjZlBLV3F50o-qhx8vcyH8lfepYGCNoFI_1786388569 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 --- .../internal/software_isp/debayer_params.h | 7 +- src/ipa/simple/algorithms/lsc.cpp | 96 +++++++++++++++++++ src/ipa/simple/algorithms/lsc.h | 55 +++++++++++ src/ipa/simple/algorithms/meson.build | 1 + src/ipa/simple/ipa_context.h | 5 + src/ipa/simple/soft_simple.cpp | 2 + 6 files changed, 165 insertions(+), 1 deletion(-) create mode 100644 src/ipa/simple/algorithms/lsc.cpp create mode 100644 src/ipa/simple/algorithms/lsc.h diff --git a/include/libcamera/internal/software_isp/debayer_params.h b/include/libcamera/internal/software_isp/debayer_params.h index 93dcf42e6..2d6fde780 100644 --- a/include/libcamera/internal/software_isp/debayer_params.h +++ b/include/libcamera/internal/software_isp/debayer_params.h @@ -35,7 +35,12 @@ struct DebayerParams { static constexpr unsigned int kLscValuesPerCell = 4; using LscLookupTable = std::array; - LscLookupTable lscLut{}; + static constexpr auto identityLscLut = [] { + LscLookupTable lut = {}; + lut.fill(64); /* == UQ<2, 6>(1.0f).quantized() */ + return lut; + }(); + LscLookupTable lscLut = identityLscLut; uint64_t lscLutVersion = 0; }; diff --git a/src/ipa/simple/algorithms/lsc.cpp b/src/ipa/simple/algorithms/lsc.cpp new file mode 100644 index 000000000..d515be3c2 --- /dev/null +++ b/src/ipa/simple/algorithms/lsc.cpp @@ -0,0 +1,96 @@ +/* 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->lscLut = DebayerParams::identityLscLut; + lastAppliedCt_ = 0; + } + return; + } + + if (utils::abs_diff(ct, lastAppliedCt_) < minTemperatureChange) + return; + + const auto &set = lscAlgo_.interpolateComponents(ct); + + const auto &red = set.at("r"); + const auto &green = set.at("g"); + const auto &blue = set.at("b"); + + DebayerParams::LscLookupTable &lut = params->lscLut; + 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->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..13d9f2bca --- /dev/null +++ b/src/ipa/simple/algorithms/lsc.h @@ -0,0 +1,55 @@ +/* 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 { + +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: + LscAlgorithm> lscAlgo_; + + std::vector gridPos_; + + unsigned int lastAppliedCt_ = 0; +}; + +} /* namespace soft::algorithms */ + +} /* 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 */ diff --git a/src/ipa/simple/soft_simple.cpp b/src/ipa/simple/soft_simple.cpp index 629e1a32d..f48ef76a5 100644 --- a/src/ipa/simple/soft_simple.cpp +++ b/src/ipa/simple/soft_simple.cpp @@ -163,6 +163,8 @@ int IPASoftSimple::init(const IPASettings &settings, params_->gamma = 1.0 / algorithms::kDefaultGamma; params_->contrastExp = 1.0; params_->gains = { { 1.0, 1.0, 1.0 } }; + params_->lscLutVersion = 0; + params_->lscLut = DebayerParams::identityLscLut; /* combinedMatrix is reset for each frame. */ }