From patchwork Wed Aug 5 18:35:13 2026 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Milan Zamazal X-Patchwork-Id: 27659 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 1D376C3306 for ; Wed, 5 Aug 2026 18:35:44 +0000 (UTC) Received: from lancelot.ideasonboard.com (localhost [IPv6:::1]) by lancelot.ideasonboard.com (Postfix) with ESMTP id 7B5BC68142; Wed, 5 Aug 2026 20:35:43 +0200 (CEST) Authentication-Results: lancelot.ideasonboard.com; dkim=pass (1024-bit key; unprotected) header.d=redhat.com header.i=@redhat.com header.b="MIYmHByN"; dkim-atps=neutral Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lancelot.ideasonboard.com (Postfix) with ESMTPS id 895C86812B for ; Wed, 5 Aug 2026 20:35:41 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1785954940; 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=qHC0PzQ7KXZy14IJyZbOrJ44fElVIVFURS8Jk0qdHBw=; b=MIYmHByN9y+Ob6FbtEjNNjNi1drxLxjSJ+iZYKOcCHi3rc1GfDB8UoCN6BM93WzBFST102 lzPG+etIaVMu82y0FSnWZwe2R2BS6soBIpNAKp3wnY1a13RbMDm2tqHYqDTTKI5AGHk627 tNTt+6P3QcdOuVk00I/9eYttPQtiDNw= Received: from mx-prod-mc-03.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-1-PqUOIhNLO7qWeu1VTy3Zug-1; Wed, 05 Aug 2026 14:35:38 -0400 X-MC-Unique: PqUOIhNLO7qWeu1VTy3Zug-1 X-Mimecast-MFC-AGG-ID: PqUOIhNLO7qWeu1VTy3Zug_1785954937 Received: from mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.111]) (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-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 15EE81955F3F; Wed, 5 Aug 2026 18:35:37 +0000 (UTC) Received: from mzamazal-thinkpadp1gen7.tpbc.com (unknown [10.44.48.68]) by mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 2C89E1800346; Wed, 5 Aug 2026 18:35:32 +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 v11 3/6] ipa: simple: Add LSC algorithm Date: Wed, 5 Aug 2026 20:35:13 +0200 Message-ID: <20260805183517.228901-4-mzamazal@redhat.com> In-Reply-To: <20260805183517.228901-1-mzamazal@redhat.com> References: <20260805183517.228901-1-mzamazal@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.111 X-Mimecast-Spam-Score: 0 X-Mimecast-MFC-PROC-ID: 2D0lkpt99ce0JTPPouDCcm3LWpSu7yiXKS_TitD5cIQ_1785954937 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 | 98 +++++++++++++++++++++++++++ src/ipa/simple/algorithms/lsc.h | 55 +++++++++++++++ src/ipa/simple/algorithms/meson.build | 1 + src/ipa/simple/ipa_context.h | 5 ++ 4 files changed, 159 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..02d8cf48c --- /dev/null +++ b/src/ipa/simple/algorithms/lsc.cpp @@ -0,0 +1,98 @@ +/* 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 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; + 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..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 */