[{"id":39680,"web_url":"https://patchwork.libcamera.org/comment/39680/","msgid":"<178395219183.3603632.6647266727052120660@localhost>","date":"2026-07-13T14:16:31","subject":"Re: [PATCH v5 17/36] ipa: libipa: lsc_polynomial: Move LscPolynomial\n\tfrom RkISP1","submitter":{"id":184,"url":"https://patchwork.libcamera.org/api/people/184/","name":"Stefan Klug","email":"stefan.klug@ideasonboard.com"},"content":"Hi Jacopo,\n\nQuoting Jacopo Mondi (2026-07-08 17:50:59)\n> Move the LscPolynomial class to libipa from RkISP1.\n> \n> Rename the class from LscPolynomialImpl to a simpler LscPolynomial.\n> The class is copied verbatim, only documentation has been added.\n\nI didn't compare all the lines. But just the description makes it way\neasier. Thank you.\n\n> \n> Signed-off-by: Jacopo Mondi \n> Reviewed-by: Kieran Bingham \n\nReviewed-by: Stefan Klug \n\n> ---\n> src/ipa/libipa/lsc_polynomial.cpp | 179 +++++++++++++++++++++++++++++++++++++-\n> src/ipa/libipa/lsc_polynomial.h | 46 ++++++++--\n> src/ipa/rkisp1/algorithms/lsc.cpp | 162 +---------------------------------\n> src/ipa/rkisp1/algorithms/lsc.h | 1 -\n> 4 files changed, 218 insertions(+), 170 deletions(-)\n> \n> diff --git a/src/ipa/libipa/lsc_polynomial.cpp b/src/ipa/libipa/lsc_polynomial.cpp\n> index fb6f959e5a09..f095a5a92024 100644\n> --- a/src/ipa/libipa/lsc_polynomial.cpp\n> +++ b/src/ipa/libipa/lsc_polynomial.cpp\n> @@ -2,11 +2,14 @@\n> /*\n> * Copyright (C) 2024, Ideas On Board\n> *\n> - * Polynomial class to represent lens shading correction\n> + * Polynomial based lens shading correction\n> */\n> \n> #include \"lsc_polynomial.h\"\n> \n> +#include \n> +#include \n> +\n> #include \n> \n> /**\n> @@ -109,6 +112,180 @@ void Polynomial::setReferenceImageSize(const Size &size)\n> \n> } /* namespace lsc */\n> \n> +/**\n> + * \\class LscPolynomial\n> + * \\brief Radial Polynomial LSC algorithm implementation\n> + *\n> + * Polynomial-based LSC algorithm implementation. The LscPolynomial class\n> + * implements LSC support using a Polynomial to represent the shading artifacts\n> + * map.\n> + *\n> + * \\sa LscImplementation\n> + */\n> +\n> +/**\n> + * \\fn LscPolynomial::LscPolynomial\n> + * \\param[in] sensorSize The physical sensor size\n> + *\n> + * Construct an LscPolynomial\n> + */\n> +\n> +/**\n> + * \\brief Parse polynomial LSC data\n> + * \\param[in] sets The tuning file content\n> + *\n> + * Parse the LSC data in polyomial form from the \\a sets tuning data.\n> + *\n> + * \\return 0 on success or a negative error number otherwise\n> + */\n> +int LscPolynomial::parseLscData(const ValueNode &sets)\n> +{\n> + for (const auto &set : sets.asList()) {\n> + std::optional pr, pgr, pgb, pb;\n> + uint32_t ct = set[\"ct\"].get(0);\n> +\n> + if (lscData_.count(ct)) {\n> + LOG(LscPolynomial, Error)\n> + << \"Multiple sets found for \"\n> + << \"color temperature \" << ct;\n> + return -EINVAL;\n> + }\n> +\n> + pr = set[\"r\"].get();\n> + pgr = set[\"gr\"].get();\n> + pgb = set[\"gb\"].get();\n> + pb = set[\"b\"].get();\n> +\n> + if (!(pr || pgr || pgb || pb)) {\n> + LOG(LscPolynomial, Error)\n> + << \"Failed to parse polynomial for \"\n> + << \"colour temperature \" << ct;\n> + return -EINVAL;\n> + }\n> +\n> + pr->setReferenceImageSize(sensorSize_);\n> + pgr->setReferenceImageSize(sensorSize_);\n> + pgb->setReferenceImageSize(sensorSize_);\n> + pb->setReferenceImageSize(sensorSize_);\n> +\n> + lscData_.emplace(std::piecewise_construct,\n> + std::forward_as_tuple(ct),\n> + std::forward_as_tuple(PolynomialComponents{ *pr, *pgr, *pgb, *pb }));\n> + }\n> +\n> + if (lscData_.empty()) {\n> + LOG(LscPolynomial, Error) << \"Failed to load any sets\";\n> + return -EINVAL;\n> + }\n> +\n> + return 0;\n> +}\n> +\n> +/**\n> + * \\brief Re-sample the LSC components for \\a cropRectangle\n> + * \\param[in] cropRectangle The sensor analogue crop rectangle\n> + * \\param[in] xSizes List of horizontal positions of the LSc grid nodes\n> + * \\param[in] ySizes List of vertical positions of the LSC grid nodes\n> + *\n> + * LSC tables have to be re-sampled every time a new sensor configuration is\n> + * used, as each streaming session might use a different sensor crop rectangle.\n> + *\n> + * Polynomial LSC tables can be re-sampled for a given sensor frame resolution\n> + * using a list of horizontal and vertical nodes that define the LSC grid on\n> + * which the polynomial is re-sampled on.\n> + *\n> + * \\a cropRectangle represents the size of the frame on which the LSC tables\n> + * have to be re-sampled on.\n> + *\n> + * \\a xSizes and \\a ySizes represent the position of the grid nodes vertexes in\n> + * the [0, 1] interval. In example an equally spaced grid of 16 nodes will have\n> + * each segment of size 0.0625 and the list of nodes position will be\n> + * [0, 0.0625, 0.125, 0.1875, ... , 1]. It is expected that the first position\n> + * is 0 and the last position is 1.\n> + */\n> +lsc::ComponentsMap\n> +LscPolynomial::sampleForCrop(const Rectangle &cropRectangle,\n> + Span xSizes,\n> + Span ySizes)\n> +{\n> + std::vector xPos = sizesListToPositions(xSizes);\n> + std::vector yPos = sizesListToPositions(ySizes);\n> +\n> + lsc::ComponentsMap components;\n> +\n> + for (const auto &[k, p] : lscData_) {\n> + components[k] = {\n> + samplePolynomial(p.pr, xPos, yPos, cropRectangle),\n> + samplePolynomial(p.pgr, xPos, yPos, cropRectangle),\n> + samplePolynomial(p.pgb, xPos, yPos, cropRectangle),\n> + samplePolynomial(p.pb, xPos, yPos, cropRectangle)\n> + };\n> + }\n> +\n> + return components;\n> +}\n> +\n> +std::vector\n> +LscPolynomial::samplePolynomial(const lsc::Polynomial &poly,\n> + Span xPositions,\n> + Span yPositions,\n> + const Rectangle &cropRectangle)\n> +{\n> + double m = poly.getM();\n> + double x0 = cropRectangle.x / m;\n> + double y0 = cropRectangle.y / m;\n> + double w = cropRectangle.width / m;\n> + double h = cropRectangle.height / m;\n> + std::vector samples;\n> +\n> + samples.reserve(xPositions.size() * yPositions.size());\n> +\n> + for (double y : yPositions) {\n> + for (double x : xPositions) {\n> + double xp = x0 + x * w;\n> + double yp = y0 + y * h;\n> + /*\n> + * The hardware uses 2.10 fixed point format and limits\n> + * the legal values to [1..3.999]. Scale and clamp the\n> + * sampled value accordingly.\n> + */\n> + int v = static_cast(\n> + poly.sampleAtNormalizedPixelPos(xp, yp) *\n> + 1024);\n> + v = std::clamp(v, 1024, 4095);\n> + samples.push_back(v);\n> + }\n> + }\n> + return samples;\n> +}\n> +\n> +/*\n> + * The rkisp1 LSC grid spacing is defined by the cell sizes on the top-left\n> + * quadrant of the grid. This is then mirrored in hardware to the other\n> + * quadrants. See parseSizes() for further details. For easier handling, this\n> + * function converts the cell sizes of half the grid to a list of position of\n> + * the whole grid (on one axis). Example:\n> + *\n> + * input: | 0.2 | 0.3 |\n> + * output: 0.0 0.2 0.5 0.8 1.0\n> + */\n> +std::vector\n> +LscPolynomial::sizesListToPositions(Span sizes)\n> +{\n> + const int half = sizes.size();\n> + std::vector positions(half * 2 + 1);\n> + double x = 0.0;\n> +\n> + positions[half] = 0.5;\n> + for (int i = 1; i <= half; i++) {\n> + x += sizes[half - i];\n> + positions[half - i] = 0.5 - x;\n> + positions[half + i] = 0.5 + x;\n> + }\n> +\n> + return positions;\n> +}\n> +\n> } /* namespace ipa */\n> \n> #ifndef __DOXYGEN__\n> diff --git a/src/ipa/libipa/lsc_polynomial.h b/src/ipa/libipa/lsc_polynomial.h\n> index 2caf46d2d759..17c2c34499f0 100644\n> --- a/src/ipa/libipa/lsc_polynomial.h\n> +++ b/src/ipa/libipa/lsc_polynomial.h\n> @@ -2,25 +2,23 @@\n> /*\n> * Copyright (C) 2024, Ideas On Board\n> *\n> - * Helper for radial polynomial used in lens shading correction.\n> + * Polynomial based lens shading correction\n> */\n> #pragma once\n> \n> -#include \n> #include \n> -#include \n> -#include \n> +#include \n> +#include \n> \n> -#include \n> #include \n> \n> #include \n> \n> #include \"libcamera/internal/value_node.h\"\n> \n> -namespace libcamera {\n> +#include \"lsc_base.h\"\n> \n> -LOG_DECLARE_CATEGORY(LscPolynomial)\n> +namespace libcamera {\n> \n> namespace ipa {\n> \n> @@ -52,6 +50,40 @@ private:\n> \n> } /* namespace lsc */\n> \n> +class LscPolynomial : public LscImplementation\n> +{\n> +private:\n> + struct PolynomialComponents {\n> + lsc::Polynomial pr;\n> + lsc::Polynomial pgr;\n> + lsc::Polynomial pgb;\n> + lsc::Polynomial pb;\n> + };\n> + using PolynomialComponentsMap = std::map;\n> +\n> +public:\n> + LscPolynomial(const Size &sensorSize)\n> + : sensorSize_(sensorSize)\n> + {\n> + }\n> +\n> + int parseLscData(const ValueNode &sets) override;\n> +\n> + lsc::ComponentsMap\n> + sampleForCrop(const Rectangle &cropRectangle,\n> + Span xSizes,\n> + Span ySizes) override;\n> +\n> +private:\n> + std::vector sizesListToPositions(Span sizes);\n> + std::vector samplePolynomial(const lsc::Polynomial &poly,\n> + Span xPositions,\n> + Span yPositions,\n> + const Rectangle &cropRectangle);\n> + PolynomialComponentsMap lscData_;\n> + Size sensorSize_;\n> +};\n> +\n> } /* namespace ipa */\n> \n> } /* namespace libcamera */\n> diff --git a/src/ipa/rkisp1/algorithms/lsc.cpp b/src/ipa/rkisp1/algorithms/lsc.cpp\n> index 839525f16746..b161798763cb 100644\n> --- a/src/ipa/rkisp1/algorithms/lsc.cpp\n> +++ b/src/ipa/rkisp1/algorithms/lsc.cpp\n> @@ -33,166 +33,6 @@ namespace {\n> \n> constexpr int kColourTemperatureQuantization = 10;\n> \n> -class LscPolynomialImpl : public LscImplementation\n> -{\n> -private:\n> - struct PolynomialComponents {\n> - lsc::Polynomial pr;\n> - lsc::Polynomial pgr;\n> - lsc::Polynomial pgb;\n> - lsc::Polynomial pb;\n> - };\n> - using PolynomialComponentsMap = std::map;\n> -\n> -public:\n> - LscPolynomialImpl(const Size &sensorSize)\n> - : sensorSize_(sensorSize)\n> - {\n> - }\n> -\n> - int parseLscData(const ValueNode &sets) override;\n> -\n> - lsc::ComponentsMap\n> - sampleForCrop(const Rectangle &cropRectangle,\n> - Span xSizes,\n> - Span ySizes) override;\n> -\n> -private:\n> - std::vector sizesListToPositions(Span sizes);\n> - std::vector samplePolynomial(const lsc::Polynomial &poly,\n> - Span xPositions,\n> - Span yPositions,\n> - const Rectangle &cropRectangle);\n> - PolynomialComponentsMap lscData_;\n> - Size sensorSize_;\n> -};\n> -\n> -int LscPolynomialImpl::parseLscData(const ValueNode &sets)\n> -{\n> - for (const auto &set : sets.asList()) {\n> - std::optional pr, pgr, pgb, pb;\n> - uint32_t ct = set[\"ct\"].get(0);\n> -\n> - if (lscData_.count(ct)) {\n> - LOG(RkISP1Lsc, Error)\n> - << \"Multiple sets found for \"\n> - << \"color temperature \" << ct;\n> - return -EINVAL;\n> - }\n> -\n> - pr = set[\"r\"].get();\n> - pgr = set[\"gr\"].get();\n> - pgb = set[\"gb\"].get();\n> - pb = set[\"b\"].get();\n> -\n> - if (!(pr || pgr || pgb || pb)) {\n> - LOG(RkISP1Lsc, Error)\n> - << \"Failed to parse polynomial for \"\n> - << \"colour temperature \" << ct;\n> - return -EINVAL;\n> - }\n> -\n> - pr->setReferenceImageSize(sensorSize_);\n> - pgr->setReferenceImageSize(sensorSize_);\n> - pgb->setReferenceImageSize(sensorSize_);\n> - pb->setReferenceImageSize(sensorSize_);\n> -\n> - lscData_.emplace(std::piecewise_construct,\n> - std::forward_as_tuple(ct),\n> - std::forward_as_tuple(PolynomialComponents{ *pr, *pgr, *pgb, *pb }));\n> - }\n> -\n> - if (lscData_.empty()) {\n> - LOG(RkISP1Lsc, Error) << \"Failed to load any sets\";\n> - return -EINVAL;\n> - }\n> -\n> - return 0;\n> -}\n> -\n> -lsc::ComponentsMap\n> -LscPolynomialImpl::sampleForCrop(const Rectangle &cropRectangle,\n> - Span xSizes,\n> - Span ySizes)\n> -{\n> - std::vector xPos = sizesListToPositions(xSizes);\n> - std::vector yPos = sizesListToPositions(ySizes);\n> -\n> - lsc::ComponentsMap components;\n> -\n> - for (const auto &[k, p] : lscData_) {\n> - components[k] = {\n> - samplePolynomial(p.pr, xPos, yPos, cropRectangle),\n> - samplePolynomial(p.pgr, xPos, yPos, cropRectangle),\n> - samplePolynomial(p.pgb, xPos, yPos, cropRectangle),\n> - samplePolynomial(p.pb, xPos, yPos, cropRectangle)\n> - };\n> - }\n> -\n> - return components;\n> -}\n> -\n> -std::vector\n> -LscPolynomialImpl::samplePolynomial(const lsc::Polynomial &poly,\n> - Span xPositions,\n> - Span yPositions,\n> - const Rectangle &cropRectangle)\n> -{\n> - double m = poly.getM();\n> - double x0 = cropRectangle.x / m;\n> - double y0 = cropRectangle.y / m;\n> - double w = cropRectangle.width / m;\n> - double h = cropRectangle.height / m;\n> - std::vector samples;\n> -\n> - samples.reserve(xPositions.size() * yPositions.size());\n> -\n> - for (double y : yPositions) {\n> - for (double x : xPositions) {\n> - double xp = x0 + x * w;\n> - double yp = y0 + y * h;\n> - /*\n> - * The hardware uses 2.10 fixed point format and limits\n> - * the legal values to [1..3.999]. Scale and clamp the\n> - * sampled value accordingly.\n> - */\n> - int v = static_cast(\n> - poly.sampleAtNormalizedPixelPos(xp, yp) *\n> - 1024);\n> - v = std::clamp(v, 1024, 4095);\n> - samples.push_back(v);\n> - }\n> - }\n> - return samples;\n> -}\n> -\n> -/*\n> - * The rkisp1 LSC grid spacing is defined by the cell sizes on the top-left\n> - * quadrant of the grid. This is then mirrored in hardware to the other\n> - * quadrants. See parseSizes() for further details. For easier handling, this\n> - * function converts the cell sizes of half the grid to a list of position of\n> - * the whole grid (on one axis). Example:\n> - *\n> - * input: | 0.2 | 0.3 |\n> - * output: 0.0 0.2 0.5 0.8 1.0\n> - */\n> -std::vector\n> -LscPolynomialImpl::sizesListToPositions(Span sizes)\n> -{\n> - const int half = sizes.size();\n> - std::vector positions(half * 2 + 1);\n> - double x = 0.0;\n> -\n> - positions[half] = 0.5;\n> - for (int i = 1; i <= half; i++) {\n> - x += sizes[half - i];\n> - positions[half - i] = 0.5 - x;\n> - positions[half + i] = 0.5 + x;\n> - }\n> -\n> - return positions;\n> -}\n> -\n> class LscTableImpl : public LscImplementation\n> {\n> public:\n> @@ -358,7 +198,7 @@ int LensShadingCorrection::init([[maybe_unused]] IPAContext &context,\n> * \\todo: Most likely the reference frame should be native_size.\n> * Let's wait how the internal discussions progress.\n> */\n> - algo_ = std::make_unique(context.sensorInfo.activeAreaSize);\n> + algo_ = std::make_unique(context.sensorInfo.activeAreaSize);\n> ret = algo_->parseLscData(sets);\n> } else {\n> LOG(RkISP1Lsc, Error) << \"Unsupported LSC data type '\"\n> diff --git a/src/ipa/rkisp1/algorithms/lsc.h b/src/ipa/rkisp1/algorithms/lsc.h\n> index b21c91c0d81f..2a428293cb2e 100644\n> --- a/src/ipa/rkisp1/algorithms/lsc.h\n> +++ b/src/ipa/rkisp1/algorithms/lsc.h\n> @@ -7,7 +7,6 @@\n> \n> #pragma once\n> \n> -#include \n> #include \n> \n> #include \"libipa/interpolator.h\"\n> \n> -- \n> 2.54.0\n>","headers":{"Return-Path":"","X-Original-To":"parsemail@patchwork.libcamera.org","Delivered-To":"parsemail@patchwork.libcamera.org","Received":["from lancelot.ideasonboard.com (lancelot.ideasonboard.com\n\t[92.243.16.209])\n\tby patchwork.libcamera.org (Postfix) with ESMTPS id A97E9C3264\n\tfor ;\n\tMon, 13 Jul 2026 14:16:37 +0000 (UTC)","from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id BCB566611A;\n\tMon, 13 Jul 2026 16:16:36 +0200 (CEST)","from perceval.ideasonboard.com (perceval.ideasonboard.com\n\t[IPv6:2001:4b98:dc2:55:216:3eff:fef7:d647])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id CD38D66114\n\tfor ;\n\tMon, 13 Jul 2026 16:16:34 +0200 (CEST)","from ideasonboard.com (unknown\n\t[IPv6:2a00:6020:448c:6c00:6c1f:355d:1c19:aba6])\n\tby perceval.ideasonboard.com (Postfix) with ESMTPSA id 113241049;\n\tMon, 13 Jul 2026 16:15:41 +0200 (CEST)"],"Authentication-Results":"lancelot.ideasonboard.com; dkim=pass (1024-bit key;\n\tunprotected) header.d=ideasonboard.com header.i=@ideasonboard.com\n\theader.b=\"n05j4bYP\"; dkim-atps=neutral","DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com;\n\ts=mail; t=1783952141;\n\tbh=jVKxdrqI3XzywA4yqkfuA+8VZBDNzOjfnROeUEpAO8A=;\n\th=In-Reply-To:References:Subject:From:Cc:To:Date:From;\n\tb=n05j4bYPArbJFgsL2vdHs4hENlmyXqiW4AbW4PyrZgfsn4yL7zXkYoKKI7oBWD9ju\n\t4nZK3hr0yMNNIdonxNO3qdoVHG+VgMDwMG9QtsWMlT+mL935SN4nQKsP4SF6jFypq5\n\t+e/U0k3yEM4VqL1ewSHPBmduJQ9q+MXxsj5QyIoA=","Content-Type":"text/plain; charset=\"utf-8\"","MIME-Version":"1.0","Content-Transfer-Encoding":"quoted-printable","In-Reply-To":"<20260708-libipa-algorithms-v5-17-0759d0359f52@ideasonboard.com>","References":"<20260708-libipa-algorithms-v5-0-0759d0359f52@ideasonboard.com>\n\t<20260708-libipa-algorithms-v5-17-0759d0359f52@ideasonboard.com>","Subject":"Re: [PATCH v5 17/36] ipa: libipa: lsc_polynomial: Move LscPolynomial\n\tfrom RkISP1","From":"Stefan Klug ","Cc":"Jacopo Mondi ,\n\tKieran Bingham ","To":"Jacopo Mondi ,\n\tlibcamera-devel@lists.libcamera.org","Date":"Mon, 13 Jul 2026 16:16:31 +0200","Message-ID":"<178395219183.3603632.6647266727052120660@localhost>","User-Agent":"alot/0.12.dev43+g2cacc0d03","X-BeenThere":"libcamera-devel@lists.libcamera.org","X-Mailman-Version":"2.1.29","Precedence":"list","List-Id":"","List-Unsubscribe":",\n\t","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n\t","Errors-To":"libcamera-devel-bounces@lists.libcamera.org","Sender":"\"libcamera-devel\" "}}]