From patchwork Wed Jul 8 09:25:13 2026 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jacopo Mondi X-Patchwork-Id: 27291 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 92DD5C3339 for ; Wed, 8 Jul 2026 09:25:40 +0000 (UTC) Received: from lancelot.ideasonboard.com (localhost [IPv6:::1]) by lancelot.ideasonboard.com (Postfix) with ESMTP id 43CA8660E0; Wed, 8 Jul 2026 11:25:40 +0200 (CEST) Authentication-Results: lancelot.ideasonboard.com; dkim=pass (1024-bit key; unprotected) header.d=ideasonboard.com header.i=@ideasonboard.com header.b="IJzlHq+w"; dkim-atps=neutral Received: from perceval.ideasonboard.com (perceval.ideasonboard.com [IPv6:2001:4b98:dc2:55:216:3eff:fef7:d647]) by lancelot.ideasonboard.com (Postfix) with ESMTPS id 24DCA660A7 for ; Wed, 8 Jul 2026 11:25:13 +0200 (CEST) Received: from [192.168.1.182] (93-46-82-201.ip106.fastwebnet.it [93.46.82.201]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id 703643FBE; Wed, 8 Jul 2026 11:24:23 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1783502663; bh=rQpuQHXCyAXIKUP2x9f0JycAyoGrS4OUcp9j0GEys7U=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=IJzlHq+wEPs8Ah3e4m48azngswhifYreXNUMDqYTxzsyT6515LISibP1w2RnWaDYy xzJ3ZB46yvtW0uqAXVWgQQyy85cBkSDWUc/WnGUEuuuNKfcoLpkKnb5yHBg0V0L6B4 e28STmh27Qkg0m2oIl1Qs05fwe9ya7BELj5YhXks= From: Jacopo Mondi Date: Wed, 08 Jul 2026 11:25:13 +0200 Subject: [PATCH v4 26/35] ipa: libipa: lsc: Document Components parsing MIME-Version: 1.0 Message-Id: <20260708-libipa-algorithms-v4-26-f0e99f035294@ideasonboard.com> References: <20260708-libipa-algorithms-v4-0-f0e99f035294@ideasonboard.com> In-Reply-To: <20260708-libipa-algorithms-v4-0-f0e99f035294@ideasonboard.com> To: libcamera-devel@lists.libcamera.org, Stefan Klug Cc: Jacopo Mondi X-Mailer: b4 0.14.3 X-Developer-Signature: v=1; a=openpgp-sha256; l=4242; i=jacopo.mondi@ideasonboard.com; h=from:subject:message-id; bh=rQpuQHXCyAXIKUP2x9f0JycAyoGrS4OUcp9j0GEys7U=; b=owEBbQKS/ZANAwAKAXI0Bo8WoVY8AcsmYgBqThdvUx2HTn43uPFM72pCYALjQRxGvrMNKf2+X 6bpsm35IJKJAjMEAAEKAB0WIQS1xD1IgJogio9YOMByNAaPFqFWPAUCak4XbwAKCRByNAaPFqFW POs/D/4ptHnIOv5v9D2XusHrbvj03vMPRETg7vzT0zqWTPa8CHGFM6RboCruo2w/VK/Iy+lRyZu pp8mMq+Gs6U6mEZukVgKoAFfD270gm99O+NMGLZhiGBl08/AriHcP3POlKQ2Df9/L9cn8CaFmzn W76HbnkldrnHHG60YPnahbITCFopf8BnGpv/QQNz8PQp7/hZ2PVIwAgSb9tDNbC/i96mQV2qOsf 9WWzZYozMIiPgedS1VfS4l6M3rLosBoHUmpSLAOrrfXM/HUpLVKTAilKMF0IK5X3tWHqS3dlKYx SxBHixHzkTK4k6HxkIUFndTeo+UNbTuzM7MjglN7PmUNJcXGVTmYzY1dl4StZbd+N/oUEmCbVFn fuhxXm2mLzE2K7yhl/R3E8gy1mGxvR+oi5WCk2BtGs9goHqKc5X+mQk9v+s1JZIjSOnKM7ls+fj oRUqb5XL+vtnmJF1qNA5Zr0TtQ51yf0nuy0k3E5s25qHdiWi4CUhoZZjOJ5kTktUMHTkolBLsxW wnys3qs2NGAbgtqAOukbAd0opq5pqwfwbbm7JRtdV1aMGPP8KVmcVsACwSCyGi//ColeSX729qF Wz/HZ3fqsZEMTuC6UaF7C+MUzYYxQgsih5/iRQUYYB6+VxWOd6+UWuQSgyA7ViUTL+fU47CmVC1 2F7AwZj9WsafJXQ== X-Developer-Key: i=jacopo.mondi@ideasonboard.com; a=openpgp; fpr=72392EDC88144A65C701EA9BA5826A2587AD026B 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" Document with examples how different IPA modules parse the tuning file depending on the number of colour channels they support. Signed-off-by: Jacopo Mondi --- src/ipa/libipa/lsc.cpp | 111 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 111 insertions(+) diff --git a/src/ipa/libipa/lsc.cpp b/src/ipa/libipa/lsc.cpp index 796c75f6d729..26c3e9968072 100644 --- a/src/ipa/libipa/lsc.cpp +++ b/src/ipa/libipa/lsc.cpp @@ -68,6 +68,117 @@ namespace lsc { * tables are organized per-colour temperature with per-colour components gain * vectors or polynomial coefficients. * + * The colour components names are IPA-implementation specific and depend on the + * ISP LSC engine design. Some LSC engine support 4 colour components (r, gr, + * gb, b), some only support 3 colour components (r, g, b). The name (and + * number) of the expected colour components shall be provided to + * LscAlgorithm::init() using the LscDescriptor::keys field. + * + * Example of a tabular lens shading tuning file with 'r', 'g' and 'b' colour + * components. The gain table has been here omitted, but the expected number + * of entries has to be equal to + * LscDescriptor::numHCells * LscDescriptor::numVCells. + * + * \code{.yaml} + * - Lsc: + * sets: + * - ct: 2500 + * r: [ + * .. gains table omitted.. + * ] + * g: [ + * .. gains table omitted.. + * ] + * b: [ + * .. gains table omitted.. + * ] + * - ct: 6500 + * r: [ + * .. gains table omitted.. + * ] + * g: [ + * .. gains table omitted.. + * ] + * b: [ + * .. gains table omitted.. + * ] + * \endcode + * + * Example of a polynomial lens shading tuning file with 'r', 'gr', 'gb' and 'b' + * colour components: + * + * \code{.yaml} + * - Lsc: + * type: "polynomial" + * sets: + * - ct: 2500 + * r: + * cx: 0.5006571711950275 + * cy: 0.510093737499277 + * k0: 1.5393282208428813 + * k1: -1.1434559757908016 + * k2: 4.332602305814554 + * k3: 0.0 + * k4: 0.0 + * gr: + * cx: 0.5009320529087338 + * cy: 0.511208038949085 + * k0: 1.5634738574805407 + * k1: -1.5623484259968348 + * k2: 4.846686073656501 + * k3: 0.0 + * k4: 0.0 + * gb: + * cx: 0.5012013290343839 + * cy: 0.5128251541578288 + * k0: 1.526147944919103 + * k1: -1.4316976083689723 + * k2: 4.792604063222728 + * k3: 0.0 + * k4: 0.0 + * b: + * cx: 0.49864139511067784 + * cy: 0.5162095081739346 + * k0: 1.0405245474038738 + * k1: 0.05618339879447103 + * k2: 1.8792813594001752 + * k3: 0.0 + * k4: 0.0 + * - ct: 6000 + * r: + * cx: 0.5006202239353942 + * cy: 0.5099531318307661 + * k0: 1.4702946023945032 + * k1: -0.8893767547927631 + * k2: 3.920547732201387 + * k3: 0.0 + * k4: 0.0 + * gr: + * cx: 0.500907874178317 + * cy: 0.511084916024106 + * k0: 1.5336172760559457 + * k1: -1.39964026514435 + * k2: 4.565487728954618 + * k3: 0.0 + * k4: 0.0 + * gb: + * cx: 0.5011898608900477 + * cy: 0.5126797906745105 + * k0: 1.5013145790354843 + * k1: -1.2747407173754124 + * k2: 4.514682876897286 + * k3: 0.0 + * k4: 0.0 + * b: + * cx: 0.4987561413116136 + * cy: 0.5159619420778772 + * k0: 1.0102986422191802 + * k1: 0.13263449763985727 + * k2: 1.686556107316064 + * k3: 0.0 + * k4: 0.0 + * \endcode + * * At LscAlgorithm::configure() time the LSC tables are re-sampled on the * sensor's crop rectangle in use to adapt them to the configuration in use for * a streaming session. Polynomial LSC tables support re-sampling and can be